New Gobel Power Battery DIY Kit V2 - Better quality, further improvements, cable size correct?

[@upnorthandpersonal]

This is one of the reasons I tend to recommend adding a fast fuse (Class T, BS-88 or NH type) to every battery. Also, if you really want to pull 200A, get two batteries. 200A represents a draw of 10kW and is also more than 0.5C on a typical 280Ah or 304Ah cell - better to cut that in half by adding a battery or two extra in parallel. Besides, if those cables are undersized (there are arguments against that but I won't go into that), than so are the bus bars interconnecting the cells (at terminal/stud contact at least).

[@OffGridGarageAustralia]

Correct, I always stress about proper externa; fusing or safety devices. Yes, the busbars with 20mm x 2mm are underrated too for 250A. We have tested this, right?!

Using 1/3C rate or less in and out of a LiFePo4 battery bank creates less internal cell heating and as we all should know heat means increased ageing and deterioration over time.. So adding more batteries increases overall life..

[@JdZ-2023]

Yeah, that the breaker to heavy is is no problem for me. I wouldn't trust it as a safety device anyway and use it as a manual main switch only. I definitely ad a passive fuse for safety, based upon the smallest wire. The only task of any fuse is always securing the wires.

[@schunkelndedschunke6914]

I am using a 12kW 3-phase Deye inverter and my solar system has a max load of 10kW. For that and relaxed battery current I have installed 3 boxes of the 14,3kWh GobelPower batteries. They are lying on a heavy duty rack horizontal. I am very happy with that configuration. The 3 GobelPower batteries are connected to a Victron Lynx PowerIn and the fuses are ADLER fuses with 20kA. (there is sand inside)

[@OffGridGarageAustralia]

@schunkelndedschunke6914 nice setup. That supplies power to your whole house obviously. So, a bit under 100A per battery under full load, which you probably never use...

[@belljoxer]

Andy, congratulations on the award and 100K subscribers. You are missing something here and it's not merely the cross sectional area of the wire but also the nature of the insulation and whether they are run in free air, in conduit, with other cables, etc. In general 200C rated insulated wire can safely carry 1.5 to 2 times the amperage of 100C rated PVC insulation. For the circuit breaker you should always derate the capacity of the circuit to 80%. So for a 250A circuit you should not draw more than 200A and that's a perfect match for a 200A BMS. If you had a 100A BMS then a 125A breaker would be appropriate.

[@TheAbyrvalg666]

I bought BatteryTech 280 ah batteries from Gobel a year ago for my sailbot and now I have 1440 ah of power at the boat and couldn't be happier. Gobel is a solid supplier!

[@ricardomarcelino8388]

What voltage are you working with? 12v?

[@OffGridGarageAustralia]

Oh wow, that is a solid setup!

[@TheAbyrvalg666]

@@ricardomarcelino8388 Yep that's 12v. Just drop in replaced old Sonnenchein battery banks. I just made 5 assemblies each with it's own BMS (200A JK BMS) and paralleled them. This is better for such application in terms of safety and reliability than using a centralized BMS. In addition I replaced old solar chargers with Victrons, and it works flawlessly now.

[@edwardvanhazendonk]

Wow, great to see your YT achievement in the shiny mirroring award. Well earned with all your super videos! Thanks for all your hard work in delivering us this cool content!

[@OskarHartmannsson]

200A BMS needs a 250A braker, 250A @80% is 200A and that is the standard if you are using full load over long time, the same is true for car chargers as they pull full power over a long time a 32A charger should be cabled and have a braker of 40A. and yes cable length is a thing for short cables and 50mm2 @ under 1m is good for a lot more than 250A

[@OffGridGarageAustralia]

You are using 200A from one of such a battery?

[@OskarHartmannsson]

@@OffGridGarageAustralia no absolutely not but that is a function of the BMS, if you want just 100A output the BMS size should be adjusted you don't want the braker to be smaler than the cut off in the BMS, and as a consequence the wiring wold be a lot easier with smaler gauge wire 35mm2

[@DincaSilviu61]

Hello from Romania. I have been using mb31 from eve for 4 months. They have at least 330Ah capacity, I charge them at 3.45v full. For now, I'm satisfied with the batteries, I'm waiting for the passage of time to see how they behave!

[@markmcm]

Congratulations Andy. Well done! 🇨🇦 🍁

[@jalpa9642]

Merry Christmas Andie & Wife/Family....Thank you for sharing Gobel Power DIY Kit...!

[@OffGridGarageAustralia]

Thank you. Merry Christmas🎄

[@Knightliner69]

Gobel actually posted a whole lot of short videos in the last couple of days about there products on their KZbin channel. There were some videos about the assembly of those boxes as well. Still happy about my old GP-SR-150 box and the batteries I got from them. They were a reliable supplier and it seems they are working to improve quality and developing of their products. If I need more batteries they would be my first choice for now.

[@OffGridGarageAustralia]

Yes, because I urged them to upgrade the manual and they had the ideas with the videos. Yeah, all in all Gobel is great with high quality and consistency.

[@philipbarth5937]

Thank you for your quick response. I would have never purchased the kits, if I hadn’t watched your channel. 4 kits for off grid BARN

[@johnmonroe3147]

Thanks Andy. I have a Pace version of this box sitting in the shed waiting to be built. This is very helpful.

[@peterle987]

A 250A circuit breaker is only intended for accidental short-circuit situations and must not trip on short maximum power situations within the possibilities of the BMS. The overcurrent protection of the BMS takes over the overload protection. Its short-circuit protection only. Covering the valves with that floppy plastic stuff doesnt matter. You can easily turn the front plate to insert the circuit breaker ;-)

[@jasonbroom7147]

I was listening to this video while doing something else and the second time you said "slaughtered duck" I had to back up the video to see what you were talking about! :)

[@m_cabral]

My DIY case came with two pairs of dual 8 AWG 200C cables for each line. When you work through the calculators for ampacity of combined conductors you lose some ampacity vs a single longer conductor but various rules for the US and Europe basically point to 160A as being the maximum reasonable ampacity once you derate for running at 105C max temperature in a steel chassis that can become fairly hot itself (40C). As an analog, this is the condition of a DC fast charger and other common equipment so the derating guidelines should be conservative and reliable (aka, you should believe your electrical code). If you decided to rely on the 200C insulation it’s in theory 360A capable, but I’m not going to be the person who finds out! Running the equivalent of an oven heating coil next to LiFePO4 cells seems silly. In my case I’m going to rewire with triple 6AWG when I make some changes to my setup to ensure I keep the wires cool. It didn’t come with any fuses or breakers so I added a 200A ANL fuse (which is not very quick to react) in line inside the case as a last resort to protect the wiring and prevent a fire. In a bad case I’d rather the BMS OCP apply in a safe way but in an even worse worst case I want to avoid a fire from burning the wires and terminals inside. I’m going to use a fast acting fuse externally at below 200A and breakers for the intended load. Each layer of protection protects and isolates which is why our homes are wired and protected in kind. Main breakers you should never trip, branch breakers you may trip, and device fuses/thermal breakers you will trip a few times per year. I’d rather a 20A branch fuse go than have the battery fuse go. As for who wants 11kW from their battery, it’s likely the Americas and SE Asia where Air Conditioning requirements are high due to humidity. There’s also battery storage for car charging where someone may want to charge very quickly. I’m with you though Andy, just run multiple batteries and share the load. Running three 100aH batteries with 200A capable wiring is better than running one 300aH battery with 200A wiring at 200A.

[@marcschneider7338]

Andy: I recently got the Gobel and the Yxijang DIY Box. According to your video it seems I got Gobel V2 and Yxijang V1 box. I can admit, the Gobel manual is really bad. It took me almost three times as long to build the Gobel box. I built the Yxijang box first, and it was really easy. After the two builds I would recomend the Yxijang box. They use this flexible copper bars for the main connection. This is much easier! The pcb for balancing wiring is much more convinient and time saving. I agree with you about the main switch. It could be much smaller. For the same price, you get more and better quality with yxijang. Btw: I bought both boxes by myself.

[@NaughtyGoatFarm]

Wow, congrats on the play button! Amazing.

[@holdenman8850]

Congrats on receiving your silver play button Andy.

[@OffGridGarageAustralia]

Thank you for your support

[@holdenman8850]

@@OffGridGarageAustralia You're very welcome. P.s the EFH got a few friends called Peter the other day :)

[@CantFindInYoutube]

Agree 100% with you, breakers and fuses have the function of protect the installation, that 250A will destroy it, in my case the max I use are 135A fuses. Like they separate the BMS and compression plate, had to disassemble one EEL with MB31 to move it to my attic, after 1 hour when I try assemble it the cells grow about 2cm total and need a lot of force to be able to put it back, the battery had 2 months, after a couple of years if they deform the compression plate, it can bend the BMS.

[@OffGridGarageAustralia]

Yeah, that's a good point!

[@koestich]

Are you sure that the switch is a circuit breaker (so has potential to protect a cable) OR is it just a switch disconnector? In German it would be a Leitungssschutzschalter (Circuit breaker) or a Lasttrennschalter (switch disconnector).

[@OffGridGarageAustralia]

@@koestich It's not a switch, it's a circuit breaker.

[@jamess4972]

@@koestich I love German. 22 letters for one word, so good!

[@wennyyuan0207]

HI Andy ,we are confident that we can beat their boxes in quality and price : )

[@RFDarter]

15:24 If that is true then how does any ring lug work at all? Or how dos the contact area of the busbar to the cell work out? The cross section there is far less than 50mm²

[@stocksons]

The wires in this box are probably safe for fault conditions as the current needed to melt them is very high (nearly 1000A for 4 gauge wire) and the circuit breaker would trip long before this happened and Gobel has added the fibreglass sheathes to contain any insulation melting during the brief heating during a fault. I agree a smaller breaker would be sensible for normal use of the battery.

[@OffGridGarageAustralia]

Good point, thank you.

[@m_cabral]

The 1000A he calculated could be a motor/compressor Locked Rotor Amp rating. It’s exceptionally brief. If you look at an air conditioning unit you’ll see it may use 25A at Running, 65A when it starts, and list a 40A breaker. Everything works out ok since the overcurrent is so brief but the wiring needs to be larger than the 25A rating would indicate to give some startup margin. Aren’t electrons fun!

[@dama054]

Have a great Christmas Andy

[@OffGridGarageAustralia]

Thank you, you too!

[@mikedurham4448]

congratulations andy ! .. merry xmass to u and mrs andy !... cheers

[@marcoarpago]

Congrats for the silver plate !!!!

[@wayne8113]

Thanks Andy, It makes it a lot easier than building your own shelf as we did (but takes a lot of the fun out of it if you have the skills) 😄😁👍

[@clarencewiles963]

Congratulations on your achievement. Remove the numbers and put the award in its place. 😊 And your at 101K 🎉 The vent may look covered but in reality they are still open to the air. Room to breathe is still available.

[@OffGridGarageAustralia]

Oh, that is a very good idea! I think, once the vent opens it's over anyway, regardless if there is a duct above or not.

[@rcguymike]

As an electrical engineer i appreciate the work and design time of companies like EG4 that make a nice server rack battery like the LL-S v2 and better😁. I could build a DIY but I value my time more I think😅😂. If I wanted a large non-moving pack I think I'd do like you did for your battery shelf and go full custom 😁

[@rickeemeee3252]

Merry Christmas 😊

[@OffGridGarageAustralia]

To you too!

[@johncampbell2311]

cally 1/0 AWG (American Wire Gauge) copper wire, which is suitable for most applications with this amperage, especially for shorter cable runs; for longer distances, consider using a 2/0 AWG cable to minimize voltage drop. Key points to remember: Wire gauge: Always consult a wire gauge chart to ensure the cable size is adequate for the current draw. Cable length: Longer cable runs may require a larger gauge wire to compensate for voltage drop. Application: Consider the specific application (e.g., solar power system, battery bank) when choosing the cable type and size.

[@joseo.cordero7286]

I have 3 EEL Vertical Battery Boxes with the JK BMS and I really like it. The only thing that I would improve is using a "beefier" circuit breaker. But so far it is working OK and looks great.

[@universeisundernoobligatio3283]

When I look at my aircraft wire single conductor in free air wire table. A 4Awg wire will have a 100degC temperature rise at 200Amps. Then you add the ambient temperature in the box, on a hot day say 60degC in the box. The cable and its mounting hardware will temperature cycle, creating a chance the crimp and hardware will loosen in time, increasing its resistance, which causes more heat from I^2R. Also the 200Amp breaker, what trip curve does it have? That governs at what current and how much time before it trips. Good chance the BMS will go up in smoke long before the breaker trips, therefore the breaker is just an on/off switch

[@sammaimas155]

Andy, This video is so opportune for me. I just received my MB31 batteries and Battery box kit. So good .Thanks muchly...

[@TheRonskiman]

I routinely discharge at 190 amps for an hour at a time, I do have two 48v batteries in my rack so only 95 amps per battery though. This discharge is for the saving sessions where we get fairly good rewards, not as good as last year though.

[@rcinfla9017]

Fyi, I have though breakers, 250 amp rating. Measured four of them and they run about 0.45 milliohms series resistance. This means they do not have electromagnetic instant short circuit tripping. They also take a lot of force to flip the toggle. They are pretty good breakers for Chinese breakers. When a breaker has electromagnetic short circuit latch coil it adds a lot of series resistance to breaker due to the series latch electromagnetic coil that trips quickly on high current. Typically, in 4 to 5 milliohms of series resistance range. They get pretty hot.

[@stefankaufmann8257]

@@rcinfla9017 can't follow you on that. The bimetal is heating up the CB, not the electromagnetic coil.

In your calculator you had a cable length of 30 meters when in fact they are .3 meters or so long.. A short jumper has very low resistance and thus higher power handling capacity, please use the engineer's jumper calculator and not the at length calculator and you will see the difference.. This is why you don't need a huge thick buss on the circuit board either.. I built high voltage/high current industrial control panels for several years and short jumpers were always undersized..

[@petermeier7149]

Maybe but with a cable length of 0,2m you would have two 10-11 Watt heater cables in your Battery Box🤷‍♂️

[@waynelove6851]

Correct, if you look at jCalc and alter the cable length for a given current, the cable size changes when you alter the lenght. 40 years in the electrical industry, we always take the cable length into account..

[@OffGridGarageAustralia]

I did not use any length calculation in my video. As I explained, length does not matter for ampacity.

[@jelleklinge9743]

​@@OffGridGarageAustraliayou are very wrong on this. Cable length is a great factor. 0.3 meter can handle very much. Check your formula,s

[@OffGridGarageAustralia]

@@jelleklinge9743 there is no length in any of the formulas for ampacity calculation.

[@andrewflies9119]

Thanks Andy. Your timing is exceptional. My first DYI is on it's way and didn't realize it was V2 until your video. You have saved me trying to make sense of the install manual. Great video as always and congrats on 100k subs.

[@OffGridGarageAustralia]

Thanks a lot and have fun with your project!

[@caesarvalenti2763]

I built a V1 just after Andy's original video but did not have any of the issues he had...so he probably got a prototype. My second unit is still in Customs but should arrive next week. I knew I was getting V2, but I did not know what that meant...now I know. Thanks Andy.

[@MMMM2MMMM2MMMM]

Very THANKFULL you did mention cable THICKNESS and Amperage again. All breakers indeed are rated too high and normally cable thickness is too THIN. Drawing 200A on a 25mm² will make that cable glow like a filament bulb! The flexible bar in the Yixiang V2 battery box is too thin too!

[@kuhrd]

One thing I would say about the cables supplied for inside the case is that the 50mm2 cable should be fine for chassis wiring up to 230 amps and the double 4 AWG cable is good for nearly 210 amps for chassis wiring. The breaker should be closer to 200A or they should include larger wires but I also wonder how hot those cables would actually really get when running at say 300 amps for about an hour till the batteries are dead? Remember inside a case like this we would only use the ampacity chart for chassis wiring but if this was in a wire way or open air you would use the power distribution or open air charts. Since the ampacity rating is directly related to heating and chassis wiring also counts the heat being conducted into other components from the wiring they can get away with running higher current for prolonged periods of time since the case adds a layer of safety and silicone does not melt but instead chars so the cable would contribute to the fuse or breaker melting or tripping long before the cable in the conductor would fail. Interestingly the fusing current in amps for copper wire is about 35.4 times the cross sectional area in mm2. I would say that even at 250Amps these breakers would be fine for instantaneous fault but may be a bit slow to react to a slight overload of say 300 amps but would likely eventually trip and still long before it is a problem in most cases. The BMS should trip long before this and the rest of the system should never let it the current get that high anyway.

[@MrSqueegey]

Great to know the top fit and all screw holes lined up.think they finally got it right😅😅😅

[@OffGridGarageAustralia]

Yeah, I was relieved as well. But the first ones were really prototypes...

[@yooper423]

It seems to me that they are using the 250 Amp circuit breaker as a simple disconnect and not for any protection. Definitely overkill.

[@frankbierschneider8785]

Gratulation!!! Weil deserved!! 🎉🎉

[@OffGridGarageAustralia]

Many thanks!

[@einzelkampfer2006]

What is the cross section of the bus bars? Are they adequate for 250A? I don't like how the thick cables bent over sharp metal edges. Makes all these epoxy sheets kinda useless. Also all the balance cables are touching each other. I don't think they have a fuse at the end. Interessant: Deine Videobeschreibung erscheint auf deutsch, wenn ich KZbin auf deutsch umstelle. 😀 Und herzliche Gratulation zur silbernen Platte. 👍

[@bjornemmy]

I have 6 gobel diy boxes coming delivery this friday!

[@OffGridGarageAustralia]

Sounds like a nice weekend ahead😄

[@bjornemmy]

@@OffGridGarageAustralia it Will probably take more then a weekend to do it right 😉

[@Dutch_off_grid_homesteading]

Heya, that gobel Power battery DIY battery box looks very good I would give it 4 out of 5

[@schunkelndedschunke6914]

The 1st GobelPower Box I have bought, has a built in 150A Circuit breaker and 2 mega fuses. Than they changed to the 250A circuit breaker only. GobelPower should give more space in the front for the bms and active balancer and change from the cables to copper bars.

[@mckenziekeith7434]

A very short cable connecting massive bus bars can probably carry a bit more current because the bus bars conduct the heat away. But you are right that the tables do not make any allowance for length.

[@j.k.1964]

The main error Andy makes on the cable topic is to take the table for ambient temp of 150°C. Using one for more resonable ambient temp. of e.g. 85°C (in the battery box!) would show, that continous 250Amps are possible without exceeding the usual 180°C max. temperatures for silicon cables.

[@CollinBaillie]

I'm pretty sure, you don't want a 180°C cable inside your battery box! You don't want more than about 10°C temperature rise on your internal cables. Ambient temperature should be the temperature of your environment, NOT the maximum temperature you want to see inside the pack. Take Andy's garage. He might see 45-50°C in there during summer. That would be ambient. With the battery doing nothing for a number of hours at that temperature, the cables and all else inside would equalise to that temperature. Then turn the battery on and load it up, the temperature rise in the cables (and the BMS, bus bars, etc) would heat up the internals of the pack. You wouldn't want to exceed about 65°C inside the case. So maybe 10-15°C temperature rise, worst case scenario. The battery box and parts included MUST be rated for worst case scenarios, with reasonable boundaries (they're not going to sell a general kit engineered for an environment (ambient temp) of 85°C, that would be hella expensive, and would accommodate 0.0001% of use cases). So, having the correctly sized cable would be required to prevent heat generation under the rated load to no more than 10°C, given that the cells, the BMS, bus bars etc all generate heat. I like another comment suggesting that you add more packs in parallel. You run the packs WELL under the rating, meaning you never generate potential heat under maximum rated load. This is more likely the scenario these designs are aimed at, and if Gobel (and others) were consulted on an ESS overall system, they would most likely include this advice, based on their design.

[@j.k.1964]

@@CollinBaillie No question, that high temps should be avoided within the pack. But this is not the task of the breaker - it should prevent damage of the cable and reduce the risk of fire hazard due to cable burning. And for silicon cable and usual ambient temperature of the cable it should just work out. But using a lower rated breaker would be better for the setup.

[@paulsmalser3261]

As Andy said, cable length has nothing to do with current capacity, but length of cable DOES affect voltage drop. As far as supplying a 120mm cable, I think then the bus bars would then be over their current carrying capacity.

[@bjornemmy]

Correct, And thé voltage drop in the cable is multiplied by thé current Running through it, giving thé generated heat in this cable. A shorter cable Will allow more current because thé heat generated in said cable is lower. But i agree the breaker could be lower rating to be sure, you should not pull 250A from a single box anyway...

[@frostyfroze7352]

No! shot cable will not safely carry more current, a short cable it will deliver more usable watts . e.g cable with a 100amp rating is good for a 100amps, regardless of length, now say cable 100mm length 53v x100amps= 5300w minimum voltage drop on that short cable, now that same cable at a 100meters long will have a voltage drop of 6.5v still at 100amp so 53v-6.5v=46.5v on the other end, now useable power is 46.5v x100amps= 4650watts

[@bjornemmy]

@@frostyfroze7352 lenght definatifly matters , in your example you 100m cable is using nearly 600W of power, dropping the voltage also increased thé current in the system because whatever you are Running Will pull whatever current it needs to get thé power it needs, so thé 600W of cable loss is not subtracted at thé end it is actualy added tonthe Total, a inverter Will obviously top out at peak current but if gets 10% less voltage, it Will demand 10% more current for thé same load. For short cables this voltage drop is as you mentioned, nearly nothing and thereby thé cable dous not add Andy significant added power tonthe system.

[@frostyfroze7352]

100% you need to subtract voltage drop to calculate USABLE power, now using a 100m of cable rated for 100amps and drawing 100amp is wildly inefficient as you mentioned, that aside 100amps is a 100amps the only thing that changes is usable power i.e. watts due to voltage drop.

[@Michaelhdk67]

@@frostyfroze7352you are both right, but at different terms. (As many others here) If the load at the end of a long cabel is a resistive load, a heater element, then the usabel power drops. If it is a inverter, switchmode powersupply, the amp will increase, and the voltage drop will also increase.

[@SylwerDragon]

Nice video. I mostly agree that circuit breaker doesn't have to be 250Amps. i believe 200A is plenty. but i'm using water heater that could use 8-9kW ..if i used bigger one that is 15kW instant power..then aircon 2kW ..then some cooker 5kW one microwave 2kW and one water heater(for coffee) 2kW ..so total 26kW ..ofc I'm not saying you will use it often.. that is why i have two 11kW Inverters. and max i went so far was about 18kW as test..but normally 10-12kW is max i use

[@VillageVidiot100]

I'm pretty regularly fitting domestic systems that will pull up to 250A - it makes sense under some circumstances in the UK. We have a demand reduction service which will pay signifficant ammounts of cash for you to dump power back to the grid over an hour slot. These systems will therfore run at full load for extended periods of time and need speciffying accordingly. I would always fit multipul battery packs to service a load like this and I always do a thermal camera test under full load in addition to the normal electrical safety testing. I think people confuse issues on current carrying capacity of cables and DC ripple. Shorter cables can't carry more max current just as Andy says but it is true to say that a shorter cable will cause less DC ripple. If you have a longer cable run from the packs to your inverter you may need to signifficantly oversize your cables to keep the voltage drop and consequent DC ripple down. See Victron "wiring unlimited" document for an in-depth description of DC ripple, its causes and effects.

[@stefankaufmann8257]

Current capacity is limited by cable resistance, that creates a voltage drop. Cable resistance is a function of crosssection and length. Voltage drop is a function of resistance and current = crosssection, length amd current. It's wrong to say, crossection determins the current capacity, no matter how long or short the cable is and that's also not what victron says about it. Victron talks about the connection between cable length, current amd crosssection - which give you the voltage drop - that create the ripple.

[@VillageVidiot100]

@stefankaufmann8257 cable resistance is specified in ohms per meter or more often miliohms per metre. If you have a cable with 1miliohm per meter of resistance carrying 100 amps then because P=I^2R it will dissipate 100 squared X 0.001ohms = 10watts per meter. If the installation method of the cable allows it to dissipate 10watts per meter and still stay below the rated effective temperature of its insulation then it can carry 100amps. That same 1m cable with 100amps flowing will drop 100x0.001 = 0.1 volts per meter because of the resistance per meter and the current. If we make that cable 100 meters long we can still force 100 amps down it, so long as it can dissipate 10 watts per meter, but we will drop 0.1x100 = 10v along its length. When connected to an inverter that will give you very high dc ripple. Current carrying capacity is not effected by length or voltage it is effected by the ability to dissipate heat without compromising the insulation. Voltage drop and therefore ripple is effected by length.

[@stefankaufmann8257]

@VillageVidiot100 No need to teach me...

[@zisaurierzisaurier9286]

I like the extension of the extension of the extension looks like in my home

[@OffGridGarageAustralia]

Works all the time😄

[@InspectorGadget2014]

Indeed, a smaller circuit breaker would be a way more safer choice. Look at the datasheet for a typical DC circuit breaker (so-called Characteristics Curve) where it states how the circuit breaker will react to the various currents and (especially) at what time-span it will trip (read: protect). Which can be several seconds up to several minutes(!) depending on the circuit breaker, amount of current etc etc. What people often seem to forget that the circuit breaker is not here to protect your battery (in this case/instance) but in fact the equipment connected to your battery (often the inverter). The battery can generate several hundreds of amps, no circuit breaker will be able to protect against that fast enough to avoid problems with your battery (thermals etc etc)

[@zisaurierzisaurier9286]

Hi Andy, did you are also regard heat pumps for your maximum power in addition to all your other stuff?

[@OffGridGarageAustralia]

Yes, I have three AC inside the house and they are super efficient, using less than 500W when keeping the house cool. More in a future video.

[@LynxPower-w4s]

Andy, I think you might want to check the orientation of the cable at the top of the breaker going to the main battery positive. It should come towards the front of case first and then loop round to the positive terminal

[@OffGridGarageAustralia]

That's what they had before, I think from memory. they changed the design now.

[@LynxPower-w4s]

I’ve got another 50 units coming to Scotland shortly so I will check. I always thought that the bottom part of this connection to the positive busbar would have been better with a flexible busbar. It does work though and I rate this kit well above the Seplos

[@mckenziekeith7434]

That is not silicone wire is it?

[@GapRecordingsNamibia]

Andy FYI, when using stainless steel screws you can use some bluetac or prestik to get the screws in and out of deep holes.... Been using this method for a few years, was taught this by an elderly gentleman named Hanz Schweiz, who was an electrical engineer......

[@DanBurgaud]

28:35 I managed to replace the jk bms on an existing yixiang box with 3 more piled on top. Imagine doing all that with these gooble boxes...

[@anzzgar]

Nooo, 125A is a bit too less for the battery, with around 150A youll be at the trip-level of the Breaker, which means if i ever have a peak it will trigger, and ill have to manually restart the battery. Dor the most cases id like to have the BMS stop everything and not mechanically the breaker. Also the 190A is for the cable for very very long times, it takes a long time for the cables to actually have a ambient temperature of 50-60° when in the box, and itll have to be several hours of charging/discharging with over 150A

[@OffGridGarageAustralia]

I use a 63A breaker in my battery shelf to connect other external batteries and run it on 80A forever. Yeah, it gets warm but does not trip. 150A for 20s also no problem.

[@paulg1802]

one box supplier yichun qhangyi. supplied 230AH cells box with one single pole 150amps circuit breaker.

[@twingoman2000]

hm, not really fully correct Andy what you said on the cables. As Cables are getting longer, the Resistenz is getting higher, the Voltage drop is getting higher and the Temperatur due to higher Resistance is increasing. Short to say, higher Resistance, lower voltage = higher amps going thru the cable. For DC power you can check on Cable length / thickness calculators, as longer the cable is, as thicker it should be to lower the Resistance and voltage drop. 😅 .. I think you will agree to it or check such kind of calculators

[@petermeier7149]

Cable length increases resistance, which means a higher voltage drop. The voltage drop increases the power lost in the cable, which heats up the cable and decreases the current it can carry. But Andy is right in the sense,that a short cable length cant increase the current a cable can carry. 50mm2 is definitely to small for 250 Amps🥴

[@twingoman2000]

@petermeier7149 Yeah, sure, the cable is decreasing possible load lets say but different point of view: If you pull same Wattage over the cabel by lower voltage the amps will increase right? 😉😅 means pulling 5kw on 1m is different then on 5m Also many calculators say, at a 2% voltage drop which already is high (my opinion) you can go with 50mm² at 250A on short cable length without big issues Truly bigger is always better, but on my 12v system max thickness is 70mm² and 250A is quickly reached but always with max 0,5m length 🤷

[@petermeier7149]

​@@twingoman2000 If that works in your System 🤷‍♂️ But the Voltage of the load is not really import. The cable has a defined resistance which multiplied by the amount of amps, causes the cable to behave like a resistor in series. In your cause with 0,5m 50mm2 you would have a voltage drop of 0,12V×250 Amps would mean, that each of your cables burn around 30 Watts of heat.

[@Stefanfj]

The ability of a wire to cool itself down depends on the surface area available to dissipate heat. Since wiring can be simplified as a cylinder when doing thermo calculations for steady state Qin=Qout, where you multiply by the length of for heat addition calculation, but also multiply by the same length for heat rejection calculation, the length just cancels out - its common on both sides. Length has absolutely zero impact on the ampacity of a wire. Ampacity is the determined ability of a wire to continuously carry a specific amount of current while remaining below some rated temperature (usually 60, 75 or 90 degrees Celsius) in a defined ambient condition - ampacity is one of 2 factors used to select the size of a conductor. the other is voltage drop, which is independent of the insulation material or ambient considerations.

[@twingoman2000]

​@@petermeier7149 how you calculate 10% of voltage drop? it will be at around 2-4% at 50mm² which would lead to 0,024 to 0,048v voltage drop right? with this it only "burns" around 6-12w but not 30w correct?

[@flemmingmulbjerg6124]

Congratulation on the Award. Half a year ago I bought Gobel Power Battery DIY Kit V1, with BMS Model JK200-ESS and 4A Bluetooth Balancer. I installed both in my battery pack. I'm now wiser 😊, but what do I do now? Should I remove the 4A Bluetooth Balancer or ?

[@BluBioBike]

I´ve got the V1 in August 24. Only difference of V2 to V1 is the display and dthe cable duct. The rest is the same.

[@olafschermann1592]

30:40 but now the pressure releaf valves are now covered.

[@OffGridGarageAustralia]

Good or bad?

[@olafschermann1592]

@ i think it would be better if the balance cables are on the side of the beam so that hot gases (hopefully never) have a free path of escape. If those gasses melt the cables other cells could also get angry.

[@olafschermann1592]

@ i guess yixian also provides a fire extinquishing / cooling capsulate in the case. Don‘t know how effective those would be but on batteries in EU it is apreciated (don‘t know if it is law or an insurance topic)

[@stocki_esy625]

Hab letztens ein diy kit von apexium mit jk bms gebaut. Die bms lösung mit den pcbs gefällt mir deutlich besser. Das case hat auch einen Steg zwischen den zellen, sodass die Druckplatte an insgesamt 7 punkten verschraubt wird und gleichmäßiger auf die Zellen drückt. Alle bms zu/ableitungen sind aus massiven busbars. Bin sehr zufrieden damit. Einziger nachteil. Kein Leitungsschutz. Nur eine 400A sicherung (hab halt extern abgesichert) Und keine Rollen

[@Dan-g8k5n]

nice, but i won´t hang a ~100 kg box only on 4 tiny screws on the front panel to mount it in the rack... this definitely needs a support on the back

[@joggiepretorius4271]

With all the rain have you ever considered adding some water tanks to supplement the solar and have a truly off grid solution ?

[@sammaimas155]

Good recommendation for Gobel power to include a QR Code to the latest update manual...

[@OffGridGarageAustralia]

It's an easy step, right?!

[@jamiroquai33]

If Andy is right about cable sizing, then all BMS on the market is crap. Do you know any bms board with conductors cross section above 50mm2?

[@OffGridGarageAustralia]

I'm stressing about this for a long time!

[@universeisundernoobligatio3283]

No circuit breaker is fast enough to protect the Hexfets in the BMS. The Hexfets will either fail open or short, both cases the magic smoke may be released. If the BMS Hexfets fail short you will never know until you try to shut down the BMS by the app or the BMS has not protected the battery. If the BMS Hexfets fail open the battery will not supply voltage or current. The circuit breaker has a trip curve which governs how fast it trips and at what current above its rating that happens. In the end the circuit breaker is just a switch to disconnect the battery.

[@Doppelhorn]

Actually when it comes to carrying high currents, a shorter cable will always fare better because the electrical resistance (ohms) is proportional to the length.This is precisely why you can get by with a smaller gauge wire for a smaller distance because it won't heat up as much as a longer stretch of exactly the same diameter when the same current is passing through. I am not an engineer, but I am sure there will be one in the comments to confirm this point.

[@OffGridGarageAustralia]

The ampacity is only dependant on the cross section and insulation material. Not the length.

[@twingoman2000]

@@OffGridGarageAustralia Andy, sorry, I do not want to blame in any way .. really .. but then tell me why on the Multiplus always is a table for cable thickness based on the length? As longer as thicker right? I also struggled a lot with this as I build my 12v system but you should try not to stick to given tables as this are mainly used on ac system without considering the length I really like you and your videos, so please dont get me wrong but also victron toolkit app tells you about

[@Michaelhdk67]

⁠@@twingoman2000cabel length is becource of the voltage drop. There is a minimum cabel size for the amp, but if you have long cabels you also have large voltage drop, so you need to go up in cabel size. Not becource of the amp, but for the voltage drop. This need to be calculated special whit low voltage systems, 12-48 volt, as a voltage drop here af 2-4 volt whit long cabels is much worse than a 2-4 volt drop in a 120 - 230 volt system.

[@philipbarth5937]

Congrats, I have a technical question. I purchased a kit, because of you.😂 the cells arrived this week, I will not be able to build the kit until next year. They will be stored in our barn and it is not heated. Will they be ok or should I do something different in the storage? Thanks

[@OffGridGarageAustralia]

Totally fine to store them as they are. Even if there is frost in your barn, no problem as long as you don't charge them in these temps.

[@beebop9808]

Wouldn't be DIY if they told you how to put it together. 😂 Merry Christmas!

[@OffGridGarageAustralia]

Yeah, you are right!☺️

[@vk4kws]

Isn't the current rating for continuous draw. The cables could "maybe" handle the 250a long enough to trip the breaker?

[@jackturtle131]

Congrats mate

[@cattales-mo2rd]

Hallo Andy, herzlichen Glückwunsch zur Silbermedaille. Habt ein wunderbares Weihnachtsfest in Down under! Liebe Grüsse aus Ludwigsfelde

[@HybridShedIraq]

I have to disagree Andy about cable length, with distance resistance increase voltage drop increase so you either have to increase the voltage to transfer more power or increase the diameter. that is why they are using high voltage to transfer power between cities even 400kv dc for large distance like Australia. so yes short distance you can use lower cable to carry 100A for example.

[@universeisundernoobligatio3283]

P = I^R the power peer unit length does not care how long the cable is. The watts per foot at a given current will be the same if the cable is a foot long or a hundred miles long.

[@HybridShedIraq]

@universeisundernoobligatio3283 voltage drop due to cable resistant what makes you need larger diameter cable for the same current at higher distance.

[@universeisundernoobligatio3283]

@@HybridShedIraq All depends if the voltage drop is not acceptable and the cost of the larger cable can be justified. It's system enginnering trade offs which always happen.

[@HybridShedIraq]

@@universeisundernoobligatio3283 just like comparing 1/2 inch pipe the length of 10 meter with 1 hp motor with 200 meter 1/2 inch pipe with also 1hp motor expecting you have the same water flow in the both cases 😂.

[@universeisundernoobligatio3283]

@@HybridShedIraq Voltage drop V = IR, if you keep the same wire gauge and current, every time you do double the wire length your R doubles therefore your voltage drop doubles. But your power per unit length stays the same P=VI

[@nicovosje]

I think the circuit breaker is used more for short circuit protection and not overload protection. So short term short circuit, Just like your main fuse in house.

[@OffGridGarageAustralia]

A circuit breaker is mostly to protect from a cable fire. It should match the installed cables.

[@sergejstojanovic2518]

i don't even know if what I'm asking is possible. Still, since you used Gemini in this video it reminded me that there might be an AI tool that can decrease the noise that rain makes while you talk and it might be useful for these types of situations when it raining heavily and you need to talk to us.

[@mflo1970]

Congratulations, l have used 4cm,3mm aluminium bus bars on my entire homemade bench including the bms conections 9 months later is it like the first day

[@martdaymo]

🤔 how is a fuse able to handle the same amps as the cable???

[@5nowChain5]

We need a 24v 2p8s Version. Maybe offer a case version that with side mounting points to allow rack mounting.

[@zisaurierzisaurier9286]

The damage of the heat Shrink maybe a risk not only for you but for every buyer! Since some Isolation between the cable and the case ist needed but not present anymore.

[@OffGridGarageAustralia]

What risk are you talking about?

[@zisaurierzisaurier9286]

@OffGridGarageAustralia An electrical connection between the cable with the damaged heat shrink isolation and the case.

[@OffGridGarageAustralia]

@zisaurierzisaurier9286 neither the cable nor the case can move towards each other... Seems impossible that this becomes a hazard. Even without heat shrink it would be safe.

[@zisaurierzisaurier9286]

Only for your damage or all possible damage of other buyers for the same reason? This problem does not exist with other cases. And we are talking about DIY. Do you know what other people do? Perhaps many people may damage their isolation the same way and even harder or at other places. The cable has an isoltaion for a reason and that is not for damaging it afterwards. In my opinion it is a risk and therefore a minus for the box. Wont recommend it. If i am doing DIY instead buying cheap ready 16x280ah box, it is safety. I can assure myself everything is done correct.

[@bile024]

Hi Andy! I think, your KZbin reward plate should be standing beneath the "subscriber counter" wall! Congratulations by the way on the reward, and thank you for all the knowledge that you share with us! ❤

[@OffGridGarageAustralia]

Thank you, that's a great idea!

[@CantFindInYoutube]

Congrats for the award

[@OffGridGarageAustralia]

Thanks to you and your support!

[@rickeemeee3252]

Nice work

[@OffGridGarageAustralia]

Thank you.

[@stocki_esy625]

Ich denke du musst mal ein video darüber machen, warum die Leitungslänge keinen Einfluss auf die Belastbarkeit hat. Hier sind ja scheinbar einige "profis" fälschlicherweise sehr vom gegenteil überzeugt. Studiere Maschinenbau und habe erst letztens in Wärmeübertragungs Vorlesung 2-3 beispiele mit isolierten leitern/rohren gerechnet. Da fällt die Leiterlänge wunderbar aus den gleichungen raus :D

[@gavlikor]

i have 3 DIY kit from GobelPower and two off them are version 2 they realy improved quality. In both I have recevied these 50mm silicon cables so it isn't option. First of these V2 was delivered without cable's duct but in the second one it helps me a lot to cover all balance and bms cables. for me it is right now 🐸🐸🐸🐸🐸

I could not use these 16 cell boxes or the new inverter BMS because I have 17 cell batteries to give me a little higher voltage for efficiency so I use the older JK BMS that can handle up to 24 cells in my home brew setups..

[@sebastiang2321]

For example if i take a 50mm² H01n2-d cable i can take 274A over this cable at 100% on time. So i think the silicone cables can handle this current too.

[@petermeier7149]

Bro, welding is not the same as supplying a load with 274 Amps on a 50mm2 cable. The cable insulation material doesnt increase the amount of amps. I have tested a 70mm2 cable with 240 amps continous for 2 hours and it was already at 75°C, which further decreased the amp capacity and it heated up faster and faster.

[@j.k.1964]

@@petermeier7149 75°C is nothing - silicon cables withstand 180°C for 3000h. So the cables easily withstand 250Amps continous at ambient temperatures below 85°C.

[@petermeier7149]

@j.k.1964 The Cable he listed here is recommended with a conductor temperatur of 85°C and his is 50mm2 not 70mm2. I only tested it for two hours, where it had a outside temperatur of 75°C, but showed a steady increase of heating up. And why would you want, that kind of temperatur in a closed battery box? I didnt say it, would not be possible in other circumstances, altough i would always use the diameter with a little bit of oversize in the amp department🤷‍♂️

[@sebastiang2321]

On an other website i saw if a 50mm² cable withstand a ambient temperature of 90C° and had a 30C° air temperature it can handle 275A at installation methods G. For example a NSGAFÖU cable.

[@petermeier7149]

@@sebastiang2321 Yea maybe it works stretched to the limits, but it is not like 1 or 2 Meters of 95mm2 cost a fortune

[@MatthiasSchwarz-y7z]

Leitungsschutzschalter DC 125A are sold in the big onlineshop of Jeff B.

[@diederickr]

I know it's a CB but it's it more of an isolation switch? Install a fuse in the output. Also can you test a 50mm cable at 200 amps?

[@dreckbaer]

I really do not like if there is no middle support column in the box, so that you can apply equal pressure when mounting the pressure plate. Its so funny. If one manufacturer would just make an effort to watch all your videos of the DIY battery boxes, they would be able to build the perfect battery pack for us! But well, they will just do it by trail and error. I reckon some day we will get all the features we would love to see. 😅 PS: It really would be nice to see how the Apexium DIY Battery boxes would hold up in your review.

[@natesoffroad]

What about voltage drop due to length.. creates more resistance, thus lowers the current carry capacity.

[@curioussand1339]

1:36 Did you say: "Without further to do"

[@gibo1971]

Heres a question for you. The old 200 amp JK BMS (non inverter) has twin 7AWG (10mm2?) cables soldered to the BMS. Surely these small cables cant handle 200 amps?

[@dmeyer8937]

Interesting, just looked on Gobel website and shipping to Texas is almost the same as the diy kit. So multiply price by 2 as the delivered price?

[@OffGridGarageAustralia]

Don't know, you need to contact them for that. What will happen next year with the tariffs? Makes such options like cases and cells unaffordable?

[@the_schmue2973]

Alles Jute zum silbernen Dingeling. Vorab auch schonmal nen frohes Fest für deine Familie und Dich. Guten Rutsch spar ich mir fürs nächste Video... Aber sag mal, kannst du was machen das mich YT nicht mit der krampfhaften deutschen KI Übersetzung nervt? P.S. ist zu Weihnachten wieder ne PV Quartett Runde mit dir geplant?

[@carlosgaspar74]

Personally I wouldn't like to have cables at 70ºC plus near my cells or my BMS . With a 10 to 15 KW load it's really easy to test cable temperature in the setup provided by the different manufacturers and know for sure what Amps are safe to use.

[@OffGridGarageAustralia]

Do you use 10kW from such a battery?

[@carlosgaspar74]

​@@OffGridGarageAustraliaPersonally 100A max and 150 on short peak demand in the Gobel. But it would make a good test. The cells can do 1C no problem there. It would show that the bars that connect the cells and the temperature of the cables can be the weak link. *Only thing missing is a 10 KW plus inverter 😬 Congratulations on the silver plate.

[@OffGridGarageAustralia]

@@carlosgaspar74 Thank you. I don't have a large enough load (inverter) to pull 10kW from such a battery. We can test on a 12V battery though with 250A.

[@carlosgaspar74]

@@OffGridGarageAustralia It would be a good test to put things in perspective and show in practice the dangers of not respecting the Ampacity and good practice system design.

[@Michaelhdk67]

@@OffGridGarageAustraliayou dont really need to test whit 200-300A Just test a 10A rated cabel, whit 20-30A, it should scale the same as testing a 100A cabel, whit 200-300A

[@olafschermann1592]

How do discount codes work when on the website instead of a price it says „contact seller for price“?

[@OffGridGarageAustralia]

I complained about this many times with Gobel... I don't know why they are doing this.

[@derfreiemensch]

MOREDAY 2 3 Pole 1000v 1500v Dc Mccb 125a 150a 200a this you can buy, i use this 150a Breaker from Moreday and it is work well. So no problem to find 150a Breaker

[@jameshancock]

You ignored the distance of the cable. It can handle almost 300 amps at 15 cm You’re completely incorrect about distance. You’re mistaking code which makes assumptions about length in a house and thus makes no differentiation. But your own calculator tells you you’re wrong. The longer the wire the higher the resistance AND you end up with inductance which makes the resistance worse.