WE WIRED OUR PYLONTECH BATTERIES 'WRONG' (and other misconceptions!)

[@davidbrodie5044]

It's amazing in life how often 'experts' disagree and manufacturers give conflicting advice. I think you're right to trust your own judgement and experience fundamentally.

[@deang5622]

That is because they are not experts. They tend to be electricians that think they are experts. The public thinks they are experts but the fact is they are not. Sadly electricians are the people supposedly qualified in electrical matters in to which the public routinely come into contact with, and therefore they assume they are experts. If only the public knew the truth! Most electrician's cannot do the design, analysis and simple calculations required for these kinds of things. As for using your own judgment. This a very dangerous thing to do, if you are not an expert in the subject. Your judgement is based on your knowledge which if you are not an expert, then it is not high enough. And that then is where you should turn to experts..the problem is you are turning to electricians and not qualified engineers.

[@The_OffGridFamily]

Thank you, that is definitely what we have found to be the case. We've been let down by experts before!

[@darraghfinnan3740]

Really. Maybe the "experts" are not experts? Why does this channel always think they know more than experts??

[@darraghfinnan3740]

Fyi - when you have an odd battery at the end it is likely to get hit harder as the resistance is lower in the circuit. Any chance that battery was tripping on you?

[@GregLangford89]

Remember the higher the voltage the lower the current. This is why say a 48V 3000W inverter can get away with a smaller diameter DC cable than a 12V 3000W inverter. I once bought a 12V 3000W inverter to use off some leisure batteries and was mortified at the cost of the cable per meter, the 48V stuff is much cheaper but obviously means you need 4 12V batteries in series. Good video, keep up the good work.

[@The_OffGridFamily]

Thanks for your comment, glad you enjoyed the video 😊 when we were looking at joining 12v batteries we were horrified how many we would need 😩

[@henvan8737]

I have wired my Pylontechs batteries just like you have done, This is the correct way to configure a hi output system.

[@markmcculloch2570]

Really enjoyed this video. From the country with hardly any grid supply- South Africa.

[@seangourley14]

Personally I think you are very brave to take on the project you have and then open yourself to the social media world to be scrutinised. I admire you. As you have learned there is much rubbish banded about as fact but know-it-alls who don’t know anything. I am not qualified to say anything but my opinion on the voltage limitation on the Victron power in or distributor is to do with safety and the exposed conductors. DC is safe to touch up to about 60V. The way the Victron system links together leaves exposed conductors at the end. If higher than 60V there is a real danger of electrocution if you tough both those conductors.

[@The_OffGridFamily]

Thanks for this, that sounds like a sensible theory 😊 and thanks for your support. We always get a bit nervy when it’s a solar video, especially a Pylontech one as people REALLY love them 😳 Just sharing our experiences in the hope that it helps someone 👍

[@audiotek10]

Firstly what you've done is fantastic, well done. I've been watching since the start. Nobody should ever criticise when you add more safety or use a bit of common sense engineering to achieve something, so long as you're not selling it and you have only yourself to hurt. The cables you are using there from your PV busbar to the MPPT are probably automotive cables, but you ordered them not me so I can only guess. You can check with the manufacturer about the voltage rating but it's normally up to 60V DC. Single insulated wire is available for higher voltages just like "single" cable used in 230V building wiring which is tested to 500V DC or higher once you get to higher appliance voltages. It's not about the number of layers of outer insulation, rather it's about the insulation resistance of the cable jacket you use. What is more of concern is that you have exposed terminals, you really should put some 3:1 heat shrink over the cable and the terminal on the left side PV busbar. It can get such a high DC voltage there you may not be able to let go if you touch them both. Just remember when AC passes the 0V point you can let go but DC doesn't do that. Same reason arc flash is more difficult to extinguish. You can also get a cover for the terminals on your Victron MPPT now which are reasonably cheap. It would also be safer to put your PV DINrail fuse and suppression device inside a plastic consumer unit style enclosure.

[@The_OffGridFamily]

Thanks for your comment and for the safety advice 😊👍 it’s great to hear from people who have been following us since the start. Thanks for your support 😊

[@imik3y]

Inverter doesn’t draw 400A. The fuse is to protect the cable. The cable is oversized to reduce voltage drop and DC ripple. Your correct in using multiple battery cables to your Lynx distributor but you have still wired it wrong because you’ve only used 1x pos and 1x neg cable from the Lynx to the Multiplus. Installation manual says use 2x 50mm pos and 2x 50mm neg. There’s a reason the internal DC connection has 2x connections each

[@waterboy8999]

I'd like to add my tuppence worth on your installation, I haven't a clue but I do enjoy your videos!

[@The_OffGridFamily]

Thank you 😊 We are pleased you enjoy them and thanks for the comment 👍

[@davidniquot6423]

Good spirit to come back on something you said and correct it .. !

[@4LXK]

You are off-grid, so it is all hypothetical to you, but this is a nice setup and more thought went into it than most of what i see online with off-grids. I went through learning the grid code (am low voltage electrical engineer) and self-certifying our setup for grid-tie in Finland, after going through 3 unsuccessful electricians that seem to not know our own standards and you are right to question and double check with manuals, but grid codes or standards are the better way to do that. Some things you could improve on the setup is to move all the solar and DC disconnects to a place where you and the fire department can reach them safely, in the case of fire or arcing - usually that is outside. Covering the DC terminals for the Solar may also be useful to avoid shorting them when dropping a screwdriver etc. If you are unsure about the cables and combiner boxes, usually a 1kV installation tester will show you when doing an insulation resistance test.

[@HobbyFinn2]

This is actually informative to watch. There does not seem to be a single correct way to do this but many possibilities for mistakes.

[@antoniegill7994]

Volts - Amps, Resistance and Watts are joined at the hip (Ohm's law), On the topic of the busbar/fuse rating, remember the formula is Volts x Amps = Watts, 160 Volts x 100 Amps = 16000 Watts or 16Kw. You have to consider the watts which is the power handling and always look at Volts and Amps together, not separately. (if you exceed the Watt rating of a conductor, busbar or cable it will resist the flow of current and can only get rid of the extra power in heat. I recommend getting the combiner box. Ensure the DC cables are all the EXACT same length and make a very good connection to the terminals and that each lug is crimped well, i.e from pylontech to fuse - same length, from fuse to combiner box - same length and from combiner box to inverter - same length for each string of batteries, even a 5% discrepancy in length will change the impedance of that circuit and could create a battery to become dominant and degrade faster or charge incorrectly than the other batteries over time. Another important topic is grounding your panels, see the resource below as you want to keep high Voltage from lightning or EMP outside of your house and away from your inverter/MPPT/Charger. The last link is for the NEC Handbook, look around you should find some online copies if you dont want to buy it on this link. Please read and use these resources for detailed explanation, especially the wiring unlimited pdf and use the web based cable sizing tool: www.victronenergy.com/upload/documents/Wiring-Unlimited-EN.pdf - see Page 16 www.solar-wind.co.uk/info/dc-cable-wire-sizing-tool-low-voltage-drop-calculator www.solarpowerworldonline.com/2015/08/what-is-the-process-of-grounding-and-bonding-a-solar-pv-array/ catalog.nfpa.org/NFPA-70-National-Electrical-Code-NEC-Handbook-P16530.aspx

[@The_OffGridFamily]

Thanks for your comment and for the info 👍😊

[@BC-tp8ep]

Ideally you have an equal length of cables for each battery for balanced resistance when charging or discharging. BMS will compensate though. Victron wiring unlimited guide is useful.

[@adrianhart9409]

The distribution box is probably not rated for high VDC because of the exposed terminals poking out of the end. Sure its capable of handling the higher voltage and current. But its a health and Safety issue with it being exposed. Placing a plastic guard over the terminals to keep fingers away would fix it. I built my own combiner box using a plastic Consumer unit box, dc cartridge fuses on each wire and a lightning surge protector.. Cost less than £100.

[@The_OffGridFamily]

Thanks for this, that’s really interesting to know 😊👍

[@PhilipHollowaychannel]

Loving the videos, it’s amazing how experts!!! come out of the woodwork when they spot the smallest thing. It looks great and I love the way you have all your wires open and to hand. I did this on my van electrical wall and loads of people didn’t like it. But you can trace everything. 😊

[@The_OffGridFamily]

Thanks for your comment 😊 We like the open wire look too 👍 And yeah, you’ve gotta watch out for those ‘experts’!

[@howardadams4072]

You have done it correctly, as busbars are a must. Just go and watch David Poz recent videos on the subject. I have three different pairs of LifePo4, battery manufactures Total 10kWh, with all the negatives paralled directly on to a single 40mm x 3mm copper busbar, using lubricated brass 8mm nuts, bolts and washers and the positives to a positive busbar through DC circuit breakers in a consumer unt box. 125A for a pair of UP2500 Pylontech's, 40A breakers each for two Simpliphi 2.6kWh and a single 16A breaker for an 800W battery. I use a Victron 24/3000/70 Multiplus II and it all works very well and has been since 2017.

[@The_OffGridFamily]

Good to hear your system is working so well, especially with a mix of batteries 😊 sounds great 👍

[@CoolMusicToMyEars]

What can I say the voltage ⚡ is Low from the batteries, I'm a retired UKAS Electrical Measurement Manager you won't get arcing on that, but what can happen is you can get voltage drops with high current demand if that happens you can get local heating & eventually burning of connections, to check this you can measure that voltage drop with a hand held Digital multimeter set on DC mV or Voltage ranges, measure voltage drop in each cable & across fuses terminals, that will also give you an idea 💡where voltage drops will cause heating around connections 😉 that is what you don't want to happen, that heating could cause burning & fires, You can get something like thick switchgear board or what the used in my day was a ideal backboard very heavy material to move around, good for insulation & mounting standoffs for busbar etc hard to cut its that tough, If in the future I suggest you mount all that in a Rittal 19" cabinet with lock door, those batteries look like standard 19" fitting, plus with Rittal cabinets you can get all the nice internal fittings 👍 www.rittal.com/com-en/products/PG0002SCHRANK1 They make outdoor cabinets very heavy material, www.rittal.com/com-en/products/PG0229STV1/PG0300STV1 It's only when it gets above 75V DC its classed as high voltage Look at this en.m.wikipedia.org/wiki/Low_Voltage_Directive In my system I will use busbar smart shunt Fuses attached to busbar nothing fancy to tell me if the fuse is blown you can do that with a LED in series with a suitable resistor, batteries, Victron Energy is great choice its built quality is top & after sales is good, In my day as a apprentice Instrument Engineer we went upto 80kV AC & 50kV DC, current upto 1000A from massive single cell batteries, other ways you can look at local heating is infrared thermal camera 📷 there produced by Fluke there very expensive, you can get adapters that fit on iPhone or Android phones with various different connectors, use your phone as infrared camera, high current connections you can buy from www.farnell.com you can buy anything there based in Leeds or RS Components over the trade counter both will deliver, you can buy busbar from either in set length & ceramic insulation standoffs, Hope that helps, oh welding cable might be alternative to paying overpriced solar cables again look at ratings, Offcuts of cables you might buy from cable manufacturers, I like silver plated copper PTFE insulation its expensive but high current rating a little awkward to bend if you choose thick types.

[@Lee-xs4dj]

I think the bus bar rating up to 60vdc is because it's not enclosed. Dangerous voltages just hanging out, ready to be lent against on those bars there. Also maybe the insulation isn't rated to insulate very well. Higher voltages usually require some rubber insulation.

[@philware1546]

Great video. Thanks for posting an update. I can see now you've got x2 batteries x3. That should be fine I would have thought. I'm running two stacks of 4x batteries with two DC cables (top+bottom). Seems to work so far. Hopefully you'll get a replacement for that dodgy pylontech battery as there's obviously something different about that one compared to the other six.

[@The_OffGridFamily]

Thanks for your comment 😊 We threatened the supplier with legal action and things have progressed since then, albeit slowly! 👍

[@happyglampers9053]

Loving your thick skinned approach and you’ve still got your sense of humour Fraser👍👏😊 You guys would be a perfect team for Victron to work with. Maybe drop ‘Journey with Jono’ a line. You’ll probably already know he narrates for them. And…. There was nothing wrong with riding a bike without a helmet or using a trampoline without a safety net 😂😂👍 Cheers

[@The_OffGridFamily]

Thanks for your comment and support as always 😊 We actually had a chat with Victron and Jorney with Jono, and one of our videos was featured on the Victron website a while back 👍 maybe they’d like to sponsor our minibus project 😉

[@sebastianlehmann3698]

What battery switch (the red and black ones) are you using? None on amazon seems to be rated for more than 48vDC. (They should be able to hold on 53vdc, but none of them, even the expensive ones, have clear indication of that voltage higher capacity.

[@davidniquot6423]

The fuse is not rated or sized to the inverter power ... BUT to the cable, the fuse is here to protect the cable, not the inverter, if something go wrong .. it cut the circuit before the cable melt and maybe catch fire. IF the inverter is too draw 400A AND the Pylontech cables are rated 100A, then you need to make 4 strings of 2 batteries in parrallel. (4x100A = 400A). If the inverter only draw 200A max then 2 strings of 4 batteries is ok. All parallels need to be connected together and from ehre a 400A cable to the inverter, i would add one breaker per string inc ase you need to work on one pair of Pylontech. Those fuse you got are fine if they can whistand 5000A and break at 150A. PV wires just got a coating that resist UV and high temperatures, there is nothing else special about them, and of course they are multi threaded (this is the word in english i think) with a minium of threads. Let's say .. those cables combine what's better for PV use.

[@ticso24]

The busbar itself should be fine for the PV voltages, unless you are using 600V strings or such. The concern is if you are using fuses, those can arc if they trip at a high voltage. If you need fuses depends on the panels, things are fine with 2 strings and sometimes with 3. This is to protect a faulty string to be backfeed and overloaded by the remaining other strings. They should have a gPV trip characteristic. For the batteries - you do need some additional fusing because the electronic protection can fail. And as long as you are using the 58V rated mega fuses, those will be fine. You can get them for 32V though, which can be a problen.

[@The_OffGridFamily]

Thanks for your comment 😊 We use string fuses for our panels 👍 Our concern with the mega fuses is the lack of short protection, which is why we used the others instead.

[@kevinmatthews2620]

i have watched a lot of nicholas howells videos, he is a bit like you in some respect a mad scientist type in his garden shed, hats off to you for getting to the root of the problem, likewise with nicholas and his diy powerwall with the kitt style leds :)

[@The_OffGridFamily]

We have a lot of respect for Nick. He was putting out really useful info before anyone else and helped us loads 😊

[@MichaelPickles]

This is a great episode! Loved it. I'm in similar position. Wondering how to wire up. I'm going to be doing halfway pairs

[@The_OffGridFamily]

Glad you enjoyed the video 🤩 We enjoyed laying the sh*t bare 😂

[@firefox7530]

Well, thanks for posting my advice, haha I do not have a beef with you. I think it is very dangerous to say it is well proven to work. Yes, maybe it is, NOW, but systems will tend to fail over time, so will also isolation of cables change over time. Why do you think have modern good inverters a so called isolation resistor check where they measure fault voltage to ground which is because of failing isolation OVER TIME or if for example a bird picked into the isolation of a cable. All SMA PV inverters I installed in the last years for example have this check built it. The higher the Voltage of your DC String is the more easily an Arc can JUMP several inches. The outgoing poles of your "DIY Combiner Lynx" are NOT COVERED. Stick a metal screwdriver or simply a metal wristband of a watch near the both poles and watch how fast the ARC is really badly injuring yourself or whoever is working on your system. See here for demonstration: kzbin.info/www/bejne/iWrEY6KGeK6AqJI or more educational here: kzbin.info/www/bejne/rnWvfH-ki8mfjac (5-10 Arc flash injuries a day only in the US!!!) And that was not a lot of volts on that string! only 4 panels with around maybe 150-160V. The DC arc will NOT stop believe me when I say that so called fireproof sheet behind your installation will start to burn if this is going on for a long time of period. I love your videos and I love that you showed your installation. I just want you and also others who watch them to be safe. High Voltage DC Strings are very very dangerous, more than you might think. Just watch the videos I provided. Just a word about the Pylontechs, which I also use with 3 MP2 3000VA inverters. You can actually use 2 positive and 2 negative wires per Group and double the amount of current capabilities. So therefore you can have one long positive wire at the top and one long at the bottom of the group both going to the busbar. You can run yours like this but your then still limited to 100A continous as you just use one cable per group. If you want to step up I propose to use 2x2 per group and you then easily have 200A per group which would make it easiy to have 4 in a group and still have 200A current. Sadly this Amphenol terminals will only go up to 35mm2. Thats the max the connector will handle. Thats why pylontech in their original manual for the C series, which is different to the non-C series, is even showing this connection possibility. It is working fine in my 3 phase System like that.

[@The_OffGridFamily]

Thanks for your comment 😊 More evidence as to why we called you ‘The One That Was Right’. We’ll have a think about what you’ve said. Until then, no watches! 😳👍

[@jimbosun2]

Arr the joy of youtube. Amazing advice from people who know and care mixed with the advice of pipe and slippers. Glad you've made up with the box at the end tho. Gonna call it a box because I'm a garage chair expert and not a actual expert. Though in my head iam obviously an expert🤔. Great video guys and a warning to us all.

[@The_OffGridFamily]

😂😂😂 Yes there’s experts in all walks of life. Take your dog out for a walk and you’ll meet 20 dog experts on your travels. Thanks for your comment 😊👍

[@PaulHughes-hd5vq]

Hi don't know if anyone has let you know about the victron lynx but it is rated at 60VDC as it has exposed terminals at the end and one you get over a certain Voltage on DC it has to have enclosed terminal to avoid shock risk this is why they are supposed to only be used on the low Voltage side of the battery system as they usually only go upto 48V which is below safe touch voltage. This means you can touch it but it will not overcome the human body resistance to give a shock. hence the low voltage rating but high amps.

[@deang5622]

So you have an exposed busbar? What's the voltage on it?

[@stewartj00701]

Only thing I can add that might be a help is the parallel cable lengths from each battery pair must be identical to each other battery pair for even charging and discharging.

[@The_OffGridFamily]

Thanks for your comment 😊 our cables are 👍

[@marcobrian1619]

This is a hard one as no two systems are the same (unless payed and fitted). It's all a big learning curve for us all. IV done 10yrs on commercial generators, this is still a learning curve for me..... But like you IV used my head and now how to build my system......I'm still learning. But I get so many asking me this and that.....I can't answer them coz thay have no flipping clue what there doing, then thay ask prise......that's when I see brown slugged around there ankles. Folk think just slap some panels up and put it in here with afew nackerd lead acid starter battery I'll be quids in. As you know it's somuch more.

[@The_OffGridFamily]

This is true. It has been a massive learning curve for us, and still is. People giving incorrect advice makes it so much harder, but that’s just the Wild West nature of KZbin isn’t it?!!😊

[@simonpeggboard4004]

Bus bar calculation for copper is roughly 1.2 x cross sectional area = current capability. There is no skin effect in DC. The Voltage is irrelevant until you hit the breakdown voltage of the insulators (usually between 600-1000V).

[@DomHogan]

I’m afraid you don’t have enough batteries for the peak surge on the 10kva Victron. Victron also state the minimum number of Pylon batteries for each Multi or Quattro. Pylon spec sheets also state the maximum current per unit. The larger Pylon units can also handle much larger demand. You are right about your fusing and cables though although, but you need to check every element for longevity. I’t not easy. Keep going we really enjoy your channel.

[@DomHogan]

Hope that helps, use the lower figures for output which corresponds to a battery that’s not fully charged.

[@derekcfoley]

Love your videos. As an ex electrician in a past career, I always thought the series connection and stacking of the Pylontech batteries always seemed a bit bizarre to me, after all, the more current, the thicker the cables required, I have a 5000 model Pylontech battery on order and have the rest of the kit all ready to connect on grid to my new Multiplus II 5000 GX. After ordering parts ready - I was quite surprised to see how small the standard "end" 2 metre Pylontech cables really are as I've not worked with AWG cabling before. I certainly wouldn't want to run more than 100A or 150A at a push through such cables at 48V. So I think what you've done is very sensible parralel connecting them onto a bus-bar. Additionally, I'm interested in your fuse holders / isolators - can you post a link or tell me the phrase to look for please!? Keep up the good off-grid work!

[@ajaxharg]

They are parallel connected even in the photos you see.

[@ajaxharg]

The cable is rated higher than you might expect as the insulation can take a higher temperature than normal.

[@The_OffGridFamily]

Thanks for your comment 😊 we got the fuses from Bimble solar. www.bimblesolar.com/DC-fused-disconnect-2pole

[@derekcfoley]

Many thanks. Funnily enough I have bought from Bimble Solar before but didnt think about looking for these there! Cheers!

[@venanciofaial]

Hi, have you tried, for example just 2 batteries to see if the problem continues?

[@The_OffGridFamily]

We’ve gone down to 6, removing the troublesome one and no problems since 😊👍

[@shitina.bucket9699]

I'll tell ya what tho, if I was to start over or when I need new batteries I'll prob just buy a few eve cells and make my own, good video don't mind the cowboys you're doing fine🤠⚡👍

[@w3bb0y]

Also cheaper than plyontech

[@evil17]

Cheaper & Better with a good BMS, I like the JK BMS’s

[@shitina.bucket9699]

@@evil17 I'll look into the jk bms thank you =)

[@The_OffGridFamily]

Thanks for the comment 😊 glad you enjoyed the video 👍

[@shitina.bucket9699]

@@The_OffGridFamily I know this is gonna seem a bit random, concept 'Grow a Home' get a few chimney sticks and cable tie them together to make a dome like structure like 2meters radius and each stick 1foot apart then plant willow at the base of each stick and train it along the sticks tuck any stray branches over to the next willow anything that can't be tucked take a cutting of and plant near by,cuttings can be used to fill in any gaps, once the dome is grown plaster it with hemp lime(so far this is a carbon negative structure) paint the whole thing with 2 coats of epdm liquid rubber, the chimney sticks can be reused to create more domes 🌱🏡🌱we live amongst the willow its chill tho,cosy domes from trees they're grown🌱🏡🌱

[@noahriding5780]

I grew up in the 80s also... and everyone I grew up with cheated through school at some point except me. So this makes me wonder how do you know if such and such batteries really do have the amp hours they stated? I mean... those guys probably cheated through school too. People that don't cheat just don't get noticed to get hired because they look boring. So... what do you think on this? (Battery amp hour accuracy) ... Also whether or not you wire the batteries parralel or series really depends on if you want a 24 volt or a 12 volt system or whatever. But I don't know yet if it matters if solar panels have to be parralel? I mean if batteries can be either then can solar panels be either also?

[@The_OffGridFamily]

We’re not experts by any means, but our understanding is yes panels can be in series, parallel or series parallel depending on your system size 😊

[@michaelansell9203]

Hi just changing tack for a moment, have you calculated the cost per kWhr of running your back up diesel gennie? I just ran mine and it works out at 28p/kWhr, a bit less than the new electricity price cap (32p/kWhr). This cost doesnt include depreciation, maintenance, oils, spares and so on though but then again we have no standing charge. Maybe it would be cheaper for Liz to start gifting generators instead of the price cap (just joking!)

[@deang5622]

Technically the inverter does not draw 400 amps. It is the load to which it is connected which determines the current. The 400 amps is the maximum output load current the inverter can deliver, *IF* the load requires it. So for example, if the maximum load wattage is 20kW, then the inverter need only deliver 87 amps. And you don't need an inverter with 400 amp output capability. Now let's suppose you do continue to use that 400 amp inverter, even if it is oversized, your batteries do not need to deliver 400 amps either, and you don't need to wire them in a way that delivers 400 amps. So the starting point has to be what your total load is in kW. From there, you can size the inverter and battery.

[@aureltanasan1413]

What you can do, is get a 6-8 way consumer unit, fill it with fuse holders and use 38x10 gpv ultra fast blow fuses, intended for string fusing. Your strings should come in there first, then to dc disconnect. In the same box with the dc string fuses, you can fit some spd’s rated at string dc voltage.

[@The_OffGridFamily]

Thanks for your comment, we will look into this 😊👍

[@beresheeth]

They are nuts... busbar is a must!

[@The_OffGridFamily]

Lots of scary suggestions out there for our system 😱😱😱

[@mrutubeuk]

Do you have updated guide document? Also would be good to see how you would re-approach this if you were to start again? Mate, you should start your own Victron installation company.

[@The_OffGridFamily]

Definitely not qualified to be installing other people’s Victron for them. It was stressful enough installing our own 😩😂 This is the updated version we use midsummerwholesale.co.uk/pdfs/pylon-us3000c-manual-240221.pdf 👍

[@eriklefevre5490]

Hi, I'm not here to criticize. I just want to try to help. I respect that you want to try and install all of this yourself. For real. Have you already tested whether, for example, 2 x 3 or 4 batteries do not work better? I bought this (ICM from iccsoftware) because I also had doubts about my pylontech. Since then I've been more reassured about how it works. I draw 120amp max from a 374AH pack. I helped a friend with an 8000w multiplus with a 400AH pack. (2x4 US2000C pack) Also works perfectly. My first setup also had an alarm a few times when the battery pack was only 2xUS2000C. That inverter could only draw 50 amps. Also worked perfectly with 4xUS2000C pack afterwards. This Windows software can also read Pylontech. (multisibcontrol)

[@The_OffGridFamily]

Thanks for your comment and for sharing your own experiences 😊 it’s always interesting to hear what other people do 👍

[@leeebbrell9]

i bought two us5000s recently, it tells me to have a fuse between the battery and invertor

[@deang5622]

Let's do the analysis. 6 Pylontech US3000C batteries, each with 74Ah capacity (= 3.55kWh each) giving a total capacity of 444Ah. And you've got a 400 amp inverter. I'm assuming that is the input current into the inverter. So at full load, with a full set of batteries, your batteries will be completely drained in just over 1 hour. Did you know this? 400 amps discharge current at 48 volts from those batteries is a power rating of 19.2 kW. Many houses in the UK are fitted with a 100 amp main fuse at 230 volts, which gives most households a maximum power utilisation of 23kW. So it would appear your design objective was to put together a battery installation which could feed an entire house. Would that be right? But did you know that when that happens, you can only feed power for the entire house for 1 hour. It is not likely you will be using 19kW unless you have electric heating for the premises, so it is likely that the batteries will be able to provide power for longer than an hour, way longer. Have you looked at your electricity meter and the kWh usage over 24 hours in summer, and on a cold winter's day? Do you know how long the batteries will last before becoming depleted?

[@davidw460]

Hi - as the cable voltage rating increases it’s likely that a 2nd layer of insulation is added to secure that it is safe to touch in all circumstances. Perhaps like an extension cord - insulation on the live conductor and then another layer around the whole lot. Just my thought :)

[@The_OffGridFamily]

That sounds like a sensible theory 😊 Thanks for sharing 👍

[@davidw460]

Inside an electrical appliance the manufacturers often use thinner insulation than we are used to seeing, because they know that we can’t touch it. The “second layer” is then the appliance box which we need tools to open and hopefully we have unplugged it by then … hopefully :) .

[@evil17]

Good vid & response. I think you have done well, it all looks pretty good to me, building this stuff doesn’t always come together straight away, and you are doing the right thing in assessing the overall system for weak area’s and addressing them as well you can. Hope you can get things sorted out with ur Supplier/Manufacturer, re: the battery issues, otherwise I would suggest to consider build ur own from 300+Amp Eve type cells and a good (JK) BMS. Cheers

[@The_OffGridFamily]

Thanks for this 😊 sounds like a good suggestion. We’ve threatened the supplier with legal action now so watch this space 😊👍

[@MrButuz]

Few thoughts. Glad you've gone the bus bar route with the batteries in groups of 2. I was worried you had it in one string as Pylon usually recommend. Why are you obsessing about your bus bars and fuses being rated to 200vdc? Your pylontechs run at 44vdc to 53vdc which are under the 58vdc rating of say the victron megafuses. The mega fuses will be fine which is why they are used in thousands of 48v installations around the world?

[@davidg487]

I think it is the bus bar for the incoming PV DC he is concerned about.

[@chrismorrison3298]

Are all your battery cables exactly the same length because the difference in battery cable lens will equal a different resistance which will cause some batteries to charge quicker than others bringing them out of balance, which seems to be your problem

[@donegal1983]

It’s great hearing your experience on your Pylontech batteries. I would question the suitability of using these batteries in a big storage system like yours. They maybe ok in a smaller system. One question I would have is what is the second Victron MPPT for ? If you have more than one they need to be linked together so one is the master and controls the charging that is done by the slaves. I am fairly sure you have all that done.

[@ajaxharg]

Why question? They even have extra hardware to combine even more batteries. The US5000 can have 16 without any extra hardware.

[@aureltanasan1413]

Why do they need to be linked for? I have 3 on a system working for the past 8 years non linked. Only the ve can can be linked, the ve direct are all connected to the GX hub. No need for any linking; and this is per victron manual.

[@Qosmio1955]

As Andrew said, up to 16 of these Pylontech units can be connected natively. More units can be added by using a dedicated communications hub. The idea is to match the number of batteries to the calculated load so that the current draw from each battery does not exceed the manufacturer's specification. For the US3000C this is 37A continuous and double that for short periods. Given that, 8 batteries is well within spec. As for the MPPT controllers, if using VE.Direct, you can use DVCC in the GX device and configure it to use a single voltage source as the reference voltage. Once that is done two completely different MPPTs will work together beautifully. Sometimes a system requires this sort of thing. For example, if the number of panels you have connected in series and parallel exceeds the rating of one MPPT, but the extra panels don't justify another larger MPPT, then adding a smaller unit is both feasible and desirable. As long as they are each capable the same output voltage then mixing and matching fine.

[@The_OffGridFamily]

We have two MPPTs as we have 2 solar arrays. One 16 panels and one 4. They communicate with each other through the Cerbo GX, like the other comments have said 😊👍 Glad you’ve found our Pylontech videos useful and thanks for commenting 😊

[@wilhelm-thomasmicu1690]

The problem with the pylontech is probably a needed firmware update. Because of the chip shortage pylontech installed a different chip than usual. This chip sometimes creates an error. Here the video how to do the update: kzbin.info/www/bejne/n6u9oZt9jNOqpJo

[@dtvking]

🤣😂🤣😂 Love it

[@The_OffGridFamily]

😂 Glad you enjoyed it 👍

[@BrazzaB1]

I could not see the PV connections, but treat them with care! There is a reason why the batteries are around 50v. Any voltage higher can be lethal. You mentioned 90v and that voltage can give you a bad day. Also note that if you get electrocuted by DC, and you are gripping the conductor, you cannot let it go!

[@olavhautekees5513]

Boy , do i see more than 1 thing wrong or nothing at all…. ?

[@Songomx]

My dears, you should have gone with the recommend Victron Energy battery bank schematics (2 battery banks of 4 Pylontech batteries each)... not more, because it's a known fact that it's very difficult (not to say impossible) to balance out batteries and cells in more than 2 parallel battery banks (you intended to use 4 battery banks, hence the problems with the individual batteries and their frequent alarms)... if I remember correctly, I recommended exactly that some time ago and you just explained your lack of space in the attic to do that... 🤔🤔 On the other hand, you should have balanced out your batteries as soon as you got them (Pylontech ships them at 50% SOC)... don't remember seeing you do that ... forgive me if I'm wrong... putting them to work at that state, is a BIG mistake... sorry to say...😔😔 Last but not least, you're right, you should get your combiner box on the PV DC side... Hope you can figure it all out and get rid of your battery issues... Cheers...!!! PS: Go with 2 stacks of Pylontech batteries (4 or less each), please... that works...!!!😀😀

[@aureltanasan1413]

He has balanced them even better, in two’s. Why you question something before you understand how it’s wired?

[@Songomx]

@@aureltanasan1413 Sorry, but I understand PERFECTLY... I have studied Battery based inverting... more than 2 battery banks in parallel is WRONG...!!! Even Victron Energy says so... An balancing batteries is ONE thing and putting them to work WITHOUT balancing is another issue... Study a little bit before you give a criteria, Sr...

[@obajer]

To be honest, the real trouble here is, that they had 2 "lemon" batteries in the pack of those 8. First one was dead on arrival, second has a faulty BMS and throws "internal error" all the time. Dealer is the one to blame: he should swap the BMS boards, or replace those 2 batteries. But he's playing hide & seek instead. Speaking of cables and lack of PV combiner box: yeah, it would be better to fix these, but it has nothing to do with the fact that these 2 batteries are having faulty BMS.

[@The_OffGridFamily]

Alfredo, we had a little look back at your first comment on our channel and you said we should stack the batteries in one pile and use one set of DC cables. 🔥🔥🔥🤔

[@Songomx]

@@The_OffGridFamily Yes, Fraser...!!! Now that you mention it... that was probably it... to make one single 48 VDC battery bank... I think it was some time ago... After that, I have been lucky enough to study Off Grid Battery Based Solar systems and I have learned a little bit more of these type of systems, hence my recommendations to not parallel more than 2 battery banks and to always balance your batteries (naturally in parallel or to top balance them with a charger) BEFORE putting them to work with your loads... Anyway, now you're in a situation that you have to try to make the best of what you got... so, if it was me, I would make 2 48 VDC battery banks with the batteries left working properly (6 of them if I am correct)... either 2 banks of 3 Pylontech batteries or 1 of 4 and another one of 2... it's your choice... VERY IMPORTANT: Try always to work with equal length cables ... it almost a MUST to have them working and balancing correctly... Good Luck...!!! And hello to the whole family...!!!

[@andrekriel7415]

Rubbish service from Pylontech