DIY Powerwall with LTO cells, Part 1

[@michaelmeek2457]

Worked as electrian for 46 years. I was parlayed in an accident in 2016. I enjoy watching all the different things on KZbin. I am impressed with everything you are doing. Keep it up i am sure you are helping others learn

[@williamh.2982]

Man, much respect !!! Letting the kid play with your tools, and helping with crippling the wires...

[@AbelMata-ng4bl]

We can't wait for part 2 video, you are the best on KZbin.

[@kymuddy]

David you are a great teacher you do not leave any gaps in your instruction like so many do in there Videos.

[@nickdepuy7162]

I agree with Gareth, I am an aircraft electrician as well as an ex-automotive tech and your cold crimps are all you need. If you can get the wires to push together instead of laying them side-by-side, you’ll get a higher rate of conductivity. In the aircraft industry, we have actually moved away from solder almost completely as a physical crimp is more reliable and just as good.

[@DavidPozEnergy]

Thank you.

[@TheDIYer]

you can soften metal by strongly heating and allowing it to cool at room temp

[@justintrussell7739]

The ole Annealing process works well.

[@Krummin]

Bury it in sand if you need it to slow the cooling process.

[@edwinkania5286]

I like the low melt sleeves.

[@ghwizz]

Another great vid! Seems like you've leveled up recently with your content - great to watch you develop! But you need to level up with your crimping technique - no need for the plumber's flux (that's why your tips are dissolving btw) and no need for soldering - a good crimp is a cold weld and any flux or neverseize or whatnot you introduce just compromises that!

[@timhaveron5038]

The best investment is a 10 - 14 ton crimper. You. Cancel find them on line for under $75 that includes 10-14 dies. Crimp them with one of them and you're done. Of course it's always good to dress it up with a short length of shrink tube. Especially when you color coordinate, red for for post, black for neg, green for ground......

[@mwm2929]

I have had the same issues drilling bed frame scrap angle. It is hardened for strength. I had success with a cobalt drill bit with lots of speed and cutting fluid.

[@davestech6357]

American Beauty makes large soldering irons for that purpose. They also make resistance soldering types too. Check them out. Looks like you are hooked on this stuff and they would be good in your tool arsenal. Once you use those tweezer resistance type you will say wow awesome.

[@Bennyboy-dog]

Excellent instructions David, especially with the joints and the cable terminations - big thanks. Seeing it being done by someone else makes me feel a lot more confident with my joints!! With my specific application - a camping trailer, I'm not sure about crimping then soldering (really unsure - my knowledge here is basically untested anecdotes). I can imagine that the soldering increases contact area and avoids corrosion in the joint over crimping alone, but soldering also allows solder to wick down the strands into the cable stiffening it up creating a possibility of a stress fracture. I believe crimping actually fuses many individual strands together so these individual strand joints won't corrode over time thus forming an excellent electrical connection without compromising the integrity of the cable. For a stationary application, soldering is probably great insurance, but for an environment with vibration I believe one should avoid soldering. Perhaps there is a qualified study someone knows about that can settle this with facts rather than anecdotes?

[@DavidPozEnergy]

When I make my big battery lugs I use a hydraulic crimper, and that's it. No soldering. But with this little dimple crimper on my pliers there are still tiny air pockets in there. I can't apply as much force with my grip as a 12-ton hydraulic. So I figure it's a good thing to fill those tiny gaps with solder. But I agree that you don't want the solder to flow down the wire under the insulation.

[@davejgoodall]

I build 3000A switchboards there is never a need for soldering ever soldering is for electronics get a good crimper (not pliers) use the same branded lugs and joiners if you can make sure you don't lose any strands and crimp a cold weld join is 100 times better than solder you can do cable all the way up to 95mm this way hydraulic after at.

[@yankey4]

LOVE IT BROTHER!! Keep up the nice work. GOD BLESS!!

[@DavidPozEnergy]

Thanks Bobby.

[@jseth2017]

David try a higher wattage soldering iron. I regularly use a 150 -200watt pistol grip iron for larger guage wiring. The finer strands absorb even more heat than the course strand wiring. And a cold weld/ good crimp usally wont need solder.

[@rays.2480]

get one of them Weller brands, I have a 250W unit. it's really old but still works like new.

[@endthefed602]

With a tight crimp you don't need to solder. The torch job will change the wire's temper making it weaker connection.

[@teekay1785]

I have used copper double barrel crimps sleeves actually meant to string duck decoys tough it is a little flatter the heat shrink still fits well in most cases

[@lambojoe11]

David when soldering: use flux or past on everything that solder will touch for a clean bond. Think of using the melting solder on the soldering iron as a way to take the heat source with the Melting solder from the soldering iron over a bridge to the wires. After pasting everything that the solder needs to touch. 1st Add solder to the soldering iron. 2nd Then touch your soldering iron full of the solder to the bottom of the wire. 3rd Use the solder wire at where the soldering iron touches the wire to melt the solder wire from the soldering iron to the wire. 4th Using the solder as a bridge to spread heat and the melting solder from the soldering iron to the wire. 5th Once the solder starts to melt when the soldering iron is touching the wire you use the melting solder to bridge over the wire joint to spread the melting solder all over using the soldering iron puddle to spread over the wire with the solder as it melts. The solder will bridge from the soldering iron to the wire faster to melt than to try to heat the wire hot enough to melt the solder on the wire, use the melting solder to Bridge the transfer of melting solder over the wire. This will use less heat, prevent the wire coating from burning and from transferring heat from the joint outward. The melting puddle on the soldering iron will spread faster to the wire than from the wire to the soldering iron. You can even use this technique to tin each wire end first to bridge a joint even faster. “Tinning” is the act of pre-soldering the bare wire end, so that its appearance is like solder instead of copper. If the BMS wire was tinned first using this technique you would use half the heat, let it cool and to solder two tinned wires will solder even faster using less heat. You can even tin the sleeve you use to crimp the two tinned wires together and then the bridging of all the solder would be even faster. I wish I could have told you before and not after. When I tin anything I use a cloth rage to wipe the extra solder off of the wire or a past brush with past on it will clean off any excess leaving a shiny silver look. KZbin is a great place to learn stuff; that's why I watch you.

[@DavidPozEnergy]

Thank you for the tips.

[@Lumbeelegend]

My favorite project yet. Thank you

[@cameronhamilton1491]

Outstanding keep up the great work I'm learning a lot from you channel

[@realvanman1]

I do enjoy the videos! It’s fun watching you work on this stuff, but it is easy for us to take for granted your videography skills that make it such a pleasure to watch. Something I hadn’t thought of until you asked about my documenting a project of mine. Nice work AND nice videography!

[@DavidPozEnergy]

Thank you. Video is a steep learning curve. I'm still looking up how to do certain adjustments in the editing software.

[@Lumbeelegend]

I like to put a wet rag on the wires to soldier larger connections. Takes a little longer, but I like it better.

[@NeilBlanchard]

I think the way you are doing it here, is the better way for high current connections. The low temperature solder sleeve is not ideal.

[@DavidPozEnergy]

Thanks. You are the first to answer this question directly. I appreciate it.

[@NeilBlanchard]

@@DavidPozEnergy I have a better.bike PEBL that has a 48V brushless 1500w motor, and the low temp solder sleeves failed in summer temps after 15-20 hours of operation.

[@belovedmountain]

Crimp only no solder. DC runs on the outside of each stran of wire, by soldering you make one solid wire less surface area.

[@disneyjoe7]

Clean tip is a must for good heat transfer, tin your iron first then by heating your piece to solder place solder to item. Clear as mud I hope not.

[@flowerpt]

Lots of good tips, thanks for the video. With stranded wire I would be tempted to loosen the wire on each end a bit (untwist) and then smoosh them into each other so they go, say, half an inch past the end of the other cable. Then solder so the solder flows around all the wires making a solid connection. Definitely get a higher power soldering iron - they're quite worthwhile. Also, look up "cold solder joints" - I don't think that wrap thing will suffice in the long term. There's a chance of cracking at some point AIUI - I don't know what would happen under load.

[@dig1035]

D, so many cells, parallel and series!

[@rtw8972]

David Soldering is an art. A 30 watt soldering iron was never intended for soldering #10 wire. I would suggest purchasing a weller brand 100-250 watt soldering gun. Don’t try with another brand, weller is the best.

[@thesurvivalist.]

LTO are better used as a starter battery, because of thier high C rating, and because cold weather does not affect them as much! Especially in the northern states!

[@jackdbur]

hydraulic crimper for larger wires no soldering needed

[@gregb1714]

To get a better solder connection, fray the wires, push the ends together, twist, then solder. Better than having the wires side by side then soldering.

[@boblewis5558]

Perhaps surprisingly and somewhat counter intuitively a masonry bit will usually cut steel without much issue. Bed frames are normally just cold rolled steel but I guess some manufacturers may post harden them, if so I'm fairly sure a masonry bit would work. It MAY be necessary to grind sharper edges to the tungsten carbide tip though. I've had success with thin steel (

[@DavidPozEnergy]

Thanks. I'll have to try that next time.

[@iliazark1]

you could connect every cell on each bank in parallel to the other bank and use one bms to save some money...also that 60A rating is probably peak current...they wont be happy with that much current continuously...the manufacturer should give you a continuous current rating as well

[@jamest5149]

Don’t solder - just crimp, it forms a cold weld if done correctly

[@donraptor6156]

BS! Measure the resistance then learn

[@McCuneWindandSolar]

that Bead frame metal is a harden steel and will eat drill bits a live.

[@mitchellbarnow1709]

Awesome video, David! It's a good thing that you're strong as an ox!

[@DavidPozEnergy]

LOL. 66 pounds is not a big deal to move 15 feet. The tough ones are the LIFePO4 modules at 164 pounds.

[@mitchellbarnow1709]

DavidPoz You were lifting them up above you and mounting them on the rack, that’s not easy.

[@mitchellbarnow1709]

DavidPoz 164 pounds is a monster!

[@johnkelly7264]

Mechanical connections are best for mid to high current and temp. The low temp solder with heatshrink will melt in a flash if the system is loaded.

[@jasonbarrett1198]

Hi David. I’m looking all over the place for part 2. Can you put a link here in part 1? Thanks

[@DavidPozEnergy]

Sorry, there wasn't a part 2 because I got hate mail when Battery Hookup sold out.

[@jasonbarrett1198]

That’s unfortunate. I was really looking forward to seeing the completion of this.

[@f.a.r.o.1954]

The secret to drilling through those bed rails is to drill very very slow!

[@DavidPozEnergy]

Thanks for the tip. I'll give it a go.

[@iflnr978]

@@DavidPozEnergy are you using cobalt drill bits? they are very hard and what is used to drill stainless steel, which is really really hard to drill. i prefer cobalt to hardened steel, some large home depots have them. cobalt bits are just a little more money and you still may damage them going through hardened steel. i can't remember if you're the one that starts with a very small pilot bit and goes through the whole set of bits, drilling a little bigger each time. it might be overkill. usually the small 1/8 inch bit is lower cost and takes a beating for the other bigger bits, which then might last longer. going slow is good because the drill doesn't get so hot and burn up. you could cool the area you are drilling with ice cubes, but that may not be an efficient way to work. maybe use liquid nitrogen? maybe "cutting oil" for metal work would be a more traditional way to reduce friction/heat. the way i do it is by stopping every 30 seconds to ad more oil (i use low cost vegetable oil, but i have no idea if it's good cutting oil. jojoba oil is probably better, it is synthetic oil [i guess it's called that because it replaces petroem, AKA conventional oil] , and one of very few oils that can stand up to jet turbine engines. before engineers knew about jojoba oil, the only other oil they knew worked to lub jet turbines was sperm whale oil [i guess they kept that a secret so environmentalists would not target them]. get jojoba oil at trader joes in the cosmetics section. it is nontoxic and doesn't have any odor i can detect). i ad more oil to the hole so the actual cutting edge on bit is in oil. there's probably an expensive drill press that incorporates automatically spraying cutting oil onto the hole you're drilling, so if you get a drill press, be aware of this possibility as an option. i like your attention to detail and making things the way you want them. it's like this old house, those guys were always paying attention to detail and they never apologised for it. if you didn't care about detail, you could just use utility supplied 115VAC like almost everyone else in the US and not make these videos. i liked your little girl using the terminals and crimper. great video, thanks

[@LithiumSolar]

I think that crimp with heat shrink would have been more than good without the solder.

[@DavidPozEnergy]

Which one? I agree with you about the ring terminal, but I think the butt splice with the crimp sleeve benefits from the solder.

[@LithiumSolar]

Sorry, I was referring to the butt splice. That looked like a nicely done crimp and I've always preferred crimp-only connections for larger wires.

[@DavidPozEnergy]

Thank you.

[@marcosmmfreitas]

Hi, David. How good it would be if it were easy to find lithium batteries here in Brazil. Here I have a powerwall of 5kW 18650 batteries recycled in my system. It is great to have your own house, your own car and not least to have your own energy. 👍🏻

[@jamest.5001]

You need a bit of solder on the iron to start with , to conduct heat better, other than that it's just practice!

[@DavidPozEnergy]

Thanks.

[@BajanAlan]

@@DavidPozEnergy Also heat rises

[@danpszeniczny9664]

Bed frames are tempered steel

[@abelteixeira9544]

Maybe you can use a crimp splice to connect Bms black to that long black cable. Easy and perfect.

[@jimthvac100]

David, where is part 2?

[@DavidPozEnergy]

I never did finish this build as I got pulled off for some other things. I'ts under my workbench waiting for me.

[@mandog2142]

I thought your Volt battery build was really good and this one promises to be even better. One question I had was would tinning the wire ends and then putting on the copper crimp ring, then soldering the completed joint together be easier and maybe result in less loss of heat down the wire? Your powerwall ideas and builds are some of the most entertaining and educational! Thanks

[@DavidPozEnergy]

I tried that once. The wire on the BMS came with tinned ends. But I found that the crimp didn't look right, the hard end of the wire prevented the crimp and wire from compressing together. I cut off the tinned ends before crimping them in this video.

[@mandog2142]

@@DavidPozEnergy Thanks David

[@chrissnyder2091]

someone else commented that your soldering iron is too small their correct you need to get yourself a Weller combination 100/ 140-watt soldering gun for the bigger wire

[@onegreenev]

Bed rails are super hard so they don't bend under the weight of someone thrashing around in bed. You might try heating the areas you need to drill. Anneal them so they will drill easy and not destroy your drills. You don't need that hard of steel for your bracket.

[@DavidPozEnergy]

How hot do I need to get the steel to remove hardness?

[@onegreenev]

@@DavidPozEnergy Don't know. Im not a blacksmith but I believe a good 400 plus then let cool. Do that a few times. Then try it. But if the aluminum angle works with the weight of the batteries then that would be fine because aluminum won't rust out. No need for paint either.

[@onegreenev]

I now have 4 48volt packs charged and balanced for my Nissan Leaf Power Wall. Video coming soon. :)

[@diyrenewableenergyelectron4996]

@@DavidPozEnergy the curie point (around 1350 degrees for steel) then slowly cool.

[@Hanzo.Azmodan]

What happened to Part 2? Searched for it but nada....

[@justinneill3888]

I can't find Part 2 of this video.

[@kennethalmond8922]

Very cool. It sounds like you'll be using the 2 unused cells as you get more LTO packs... but I wasn't sure. However, if you have a few left over cells it might turn out that in case one of the cells go bad over time you'll have 1 or 2 or 4 spares that you can use to replace the bad cells - simply by re-arranging the wiring a bit. Its too late for me as I'm neck deep in 18650 but I can admire your battery banks thru these youtubes :)

[@ragingblazex5004]

soldering iron is better than torch. as it wouldn't damage the insulation, however, even for me I would go with torch for thick wire as my soldering iron wouldn't able to perform as good as your.

[@fisherus]

Dave, get you a good set of high speed carbide drill bits and they will buzz through iron like your bed frame is made from. They dissipate heat faster than any other type of bit. Be sure to use cutting oil when you drill any metal. Also, take a look at Will Prowse's newest video regarding BMS battery balancer systems being basically worthless once you parallel balance the cells at full charge. Your thoughts? If Battery Hook-up gets more of these in I think these will be the way to go as I don't want to worry about how to keep them above 32 degrees F and destroying them with over 10K watts of solar panels. Think I'll get 25 to start and hope it will be enough or I'll be able to get more if I need additional storage.

[@DavidPozEnergy]

Hi Craig, If you are starting your battery pack from scratch with LTO's, then you can go 24s and save yourself some headache cutting tabs. Yes, I was using oil, but HSS bits, not Cobalt. What do you think of this set: www.amazon.com/Drill-America-Piece-Cobalt-Round/dp/B00FXGOMIW/ref=sr_1_5?crid=1R6T675FQSKX9&keywords=cobalt+drill+bit+set&qid=1580606503&sprefix=Cobalt+drill+%2Caps%2C153&sr=8-5 As for active balancers: I ran my house on a Chevy Volt battery all last year and never had a balancer on it. They came out of the car balanced. When I bought a battery from a Smart car the cells were not in balance. I used an active balancer to help while I recovered them, but removed the active balancer when I finished. Right now I have that same active balancer on my LiFePO4 cells because I'm still bringing them together, but have no intention on leaving the balancer on there long term. When I built the Server battery there is no active balancer. No active balancer on my LTO battery I'm currently building. Who would leave it on? I always thought active balancers were just to commission a battery pack. You know, just to get it balanced initially. . Why would you leave it on there long-term?

[@kevinmills5293]

Is there a part 2?

[@JRP3]

Drilling bed frame can be a bitch, I've had the exact same problem. I think what happens is they get work hardened from the heat of drilling, so either keep the pressure low, speed low, and keep them well lubricated, or, use hardened masonry bits which have carbide tips. I've used masonry bits to cut through bed frames and hardened steel. I think bed frames are high carbon steel.

[@DavidPozEnergy]

Thanks for the tip. I'll try a masonry bit next time.

[@jasonflt]

quick and easy

[@bradquinn4161]

David. Take a look at a ferrule crimper. They work much better than the old time crimpers. In Europe they are code in most areas. You need a much bigger(higher wattage) soldiering iron(gun). For just occasional stuff harbor freight makes one for $20(?).

[@DavidPozEnergy]

Thanks. I do have a ferrule crimper, but it won't fit around these sleeves. I'll have to get a larger one. It's nice how the 4 sides come down.

[@bradquinn4161]

@@DavidPozEnergy A lot of the larger ones are hex or octagon rather than square. You need to think about where you are going to plug it into. Most of the larger "sockets" are meant for round stuff, so hex or octagon is better. Most of the smaller stuff is more suited to a "flat" mount so square works better.

[@DavidPozEnergy]

Thanks.

[@keithcress1335]

Bed frames can be made from what's called hot-rolled steel. Hot rolled is made from scrap steel that is heated hot enough to roll the whole mess together. They don't melt it all into a homogeneous liquid. That's how you can end up with areas that are crazy hard next to soft and gooey. You may be trying to drill thru a high strength bolt. I hate that stuff. Try to stick with cold-rolled steel which is homogeneous with uniform harness.

[@DavidPozEnergy]

Thank you, Metal types are so interesting.

[@abelmata5984]

Hi David, have got the chance to upload part 2 video?

[@DavidPozEnergy]

I never did get around to a part 2 on this battery. Sorry.

[@AbelMata-ng4bl]

@@DavidPozEnergy Thats ok, thank you

[@Dutch_off_grid_homesteading]

heya that looks like 1 more nice battery pack

[@DJRobbie54]

No, as far as crimping wires together I would have Twisted the wires together around each other, then (solder them together), after soldering heat shrink it and row some tape around them for Extra Protection you don't have to cramp it, (that's Overkill). And of course you would have a good fuse in-line on your circuit.

[@jessyterpoorten7197]

I had the same problem whit my solder tips i used lead free solder that eats tips! Now i use a tip from aliexpress and i use lead 60-40 solder and i still use the same tip

[@Halio1984]

you should really look into the XT connectors...they handle plenty of current where you can easily get connectors for up to 150A...but the big thing is they are connectors and not permanent connections so you can swap out the BMS at a later date.

[@DavidPozEnergy]

Thanks. I have some of those on my power supply and ISDT Q8 charger.

[@irvkanode539]

I'd use Anderson PowerPole connectors--no soldering needed. Available in many sizes from 15Amp to 350Amp. Like Hailo's suggestion, they also give you the ability to easily swap out the BMS. I use 15 amp ones for the balance wires.

[@Krummin]

I always leave a blob of solder on the tip of my iron to prolong the life of the tip

[@Whitewolf4869]

use cobalt drill bit

[@jimthvac100]

Solder does stick to these I used a 200/240 watt soldering iron with a little flux and it stuck just fine. Your doing what I am also working on. Except I canceled my 48 Volt battery pack design and am working on a 12s 24 Volt system for a Taylor Dunn 336 3 wheel 24V Maintenance truck. The charge controller and motor can easily handle the 27V pack, else I would do like you are doing and drop a cell to a 11s pack. I did not want to buy four more expensive deep cycle 6V lead acid batteries. These LTO batteries I found on Ebay will give me about 2.16kw's. Then I will throw on a 24V solar panel that will work as a "roof" to help keep the batteries charged during the day when I take the truck to outside events tractor shows (I have a bad knee).

[@suleimantanko7474]

Davidpoz good day can I have the old one I really like it.

[@mickeylewis8094]

Use a piece of wet cloth on either side of the cables and see.

[@mark_osborne]

...the number of wire nuts you use (annually) goes up exponentially with age :P Nice video !

[@DavidPozEnergy]

LOL. I can see that happening.

[@scottm3505]

David can you take 48v chevy volt battery too 12v to work on my 12v inverter

[@nkos6376]

perhaps you don't need to solder the connection. mechanical connection should be enough?

[@biehpham8323]

How are these cells working for you? Update please

[@korishan]

I wouldn't worry so much about the heat going up the wire into the bms. There is no way you put as much heat on it as they do when the assemble it. To assemble smd components, temps are around 350*C for about a minute. I doubt you got anywhere near that up that wire. 😉 For the iron tips, keep a damp sponge near by. Between uses, wipe the the tip on the sponge to clean off any residue/solder. If you are going to let it sit for a few minutes, put a little bit of solder on the tip (called wetting the tip) to cover the tip so it won't oxidize. When storing tips, wipe them clean with the sponge (just quick swipes on both sides a couple times) and then apply a heavier amount of solder to the tip, almost like you'd be using the tip to carry the solder to the work. Then pull the power to the iron. Let the solder harden on the tip. Then when you get ready to use it again, bring the iron up to temp, wipe clean on the damp sponge, and then get to work. Real brass shavings/wool will help clean the tip as well. You can get brass brillo pads in grocery stores, but make sure to take a magnet with you to make sure they aren't copper painted steel. This happened to a friend of mine.

[@DavidPozEnergy]

Thank you for all the great tips.

[@mikekendall5835]

I just bought a 36 volt golf cart .. Did you ever test to see how far you could drive before recharging?... Thanks

[@DavidPozEnergy]

I have not yet. I'm still on the original charge.

[@HomesteadingintheForest]

David, can you explain why you went with a 60 amp BMS? Thanks for posting and I really look forward to part 2. I'm thinking of installing a 36kW battery bank using these used cells and your videos have been super helpful.

[@DavidPozEnergy]

These BMS's are mosfet based. mosfets don't like surges, they tend to burn up if you overload them. So I over-size my BMS to the size of my circuit breaker. In this case I'll use 30 amp circuit breakers.

[@HomesteadingintheForest]

@@DavidPozEnergy Would this mean that doing a large build with many BMS for a 40kW battery bank would necessitate sizing the amp rating to the main panel circuit breaker? So if I wanted to use a 200 amp panel I'd need 200 amp BMSs (sorry if this is a stupid question)? This seems like a deal breaker going this route for a larger system if so right? Someone in another forum mentioned connecting each cell to a fuse block, but I don't know what that means or how it works. I've went ahead and ordered 36 1.1kW batteries so I'm all in on this tech and if I have to manually separate the cells, so be it, but I don't think that will be the case. By the way, thanks so much for answering my original question and taking the time to make these videos.

[@DavidPozEnergy]

It's hard to follow conversations in this format on KZbin. If you would like to dive into this topic, please send me an e-mail, or a message on facebook. Thanks.

[@jamess1787]

Your soldering looks fine. No globs, no funny stuff. Looks good enough for.... All? Tip for keeping tips is to keep them clean. Wipe them when you store them, even if it's only for a few seconds on the stand.

[@chrislewis2262]

Where is part #2?

[@raaah]

You can’t keep that soldering iron on that wire to long because the BMS is to close

[@mikejf4377]

Very nice video, your daughter is getting bigger. On sounder you might use a hotter soldering iron. Question why do you think you need to sounder it anyway. The crimp should work quite fine. Copper crimp. Propane torch would have a slightly tighter burn to it. What is your degree in.

[@mikezog1030]

Where is part 2 for this? And where do you get the LTO batteries?

[@DavidPozEnergy]

I got the LTO batteries from Batteryhookup.com Unfortunately, they ran out of stock, so I shelved the project.

[@mikezog1030]

@@DavidPozEnergy pity...

[@fisherus]

Sweet! My past experience using the high carbon lubricant with aluminum and steel (I assume the screws, washers and nuts are steel) caused heavy corrosion between the two metals. It's even worse if zinc plated screws were used. I was told by my electrician friend that it caused an electrolysis between the two metals. Just thought I'd share this with you. Maybe it's OK for batteries?

[@graceho99]

If you use a grid tie inverter, why do you need to use your own battery banks? Is it often that you need to deal with power outage?

[@DavidPozEnergy]

I get a power outage once or twice a year. But we once had the power out in this town for 3 weeks. Actually it was half the state. I like being prepared.

[@graceho99]

DavidPoz thanks for the replay. Has anybody calculated the maximum possible current between different batteries through the balance wires? I super that they are tiny. The max currents should be where different batteries converge and connect to inverter.

[@DavidPozEnergy]

These BMSs have a maximum 40ma current for balance.

[@AbelMata-ng4bl]

Can you drop some info for who do you email to ask for those BMS?

[@MStrickkk]

I see you bought those arctic fans I linked you a long time ago. They're still the best out for the price.

[@peterking1134]

What happened with the LIPO battery project ?

[@DavidPozEnergy]

I'm still working on my LiFePO4 project.

[@PipeManPeep]

LiFePo4. Not LiPo

[@Andrewsnotes1]

@@DavidPozEnergy My project is stalled, waiting to see what you do with yours.

[@irvkanode539]

Will you explain why you decided to first connect the batteries in series then parallel vs parallel then series? I've been planning to connect mine in parallel to get amperage and then series to get voltage. To me, it seems like the wiring would be simpler and I would only need one larger amperage BMS. • That's the way LiFePO4 packs are built. • Before connecting cells in parallel, I'd make sure the voltages are very close because the balance wires can't handle high currents. I already have a Daly 200A 48V 20S BMS on order for $183. I hope I didn't make a mistake.

[@DavidPozEnergy]

These LTO modules already came 1p8s (8 cells in series). They are welded together. For me to break them apart I'd have to cut every tab. That's why I left them in the orientation they already came in. However, if you are buying individual cells you can orient them any way you want. If that's the case then I would parallel them first and then series. Basically, I agree with you you. One BMS, simpler, easier.

[@williamhustonrn6160]

Great Video!!< I personally have used the torch method myself on my power wall, but I used just generic copper pipe I had laying around for the crimp connectors with hydraulic press. I am currently waiting on some supercapacitors to show up in the mail I ordered from China. Ordered 200 of the Maxwell 2.7V 3000F @ $15/ea in bulk price. My idea is to supersize what I have been running in my diesel pickup for the last almost 2 years. nearly 2 years ago I replaced the pair of weak batteries in my diesel pickup with a supercapacitor set up based on "Mad Electron Engineering" design, but used normal $15 12v UPS batteries instead of the lithium and 1000F cells, well those two batteries have been working fantastic without any issues. I recently had to start the truck up in -8F temps and it cranked over way faster than it ever did with the original lead-acid batteries previously. My idea is to build a rather large capacitor bank of the capacitors I ordered to be the main charge/draw point of the system, then tie my existing power wall I have already in with a resistance load between it and the capacitors, so the load is drawn from the capacitors first always and accepting the charge first. The idea is capacitors don't have nearly the cycle life issues as batteries do and can charge and discharge far faster than any battery can, so with the capacitor bank the size I'm building, hopefully, the majority if not all the power will come directly from the capacitors during the day when the solar is actively dumping energy into the capacitors, then at night, the batteries can help out.

[@jamess1787]

What kind of diesel truck?

[@Musicpins]

Damn great, i think LTO is an upcoming star, if they hold up to their ratings its a damn nice cycle count. hows this system running David?

[@whatthefunction9140]

Lto is where its at.

[@AbelMata-ng4bl]

Question David, Why a lot of people said that this cells are not good for solar storage pack? they said that the connector rods are to small to carry all that power and may damage the cells, Please advise? and yes they sold very fast I didn't even see it on battery hookup.

[@DavidPozEnergy]

There is nothing wrong with using LTO for solar power storage. LTO is typically more expensive per kWh compared with LiFePO4, so most people prefer LiFePO4.

[@AbelMata-ng4bl]

Thank you David

[@AbelMata-ng4bl]

thank you David, one more question are the actual cells inside the module are 20A or 30A?

[@DavidPozEnergy]

The cells used in this video are 20Ah cells.

[@TheDIYer]

i cant find the next video can you put a link please

[@DavidPozEnergy]

I'm sorry, I did not finish this particular project. The batteries are sitting in my garage waiting for me to finish.

[@TheDIYer]

@@DavidPozEnergy oh okay no probs just saw it

[@danelucas2579]

BMS supplier link?

[@fisherus]

Man Dave, I am so confused how to wire the BMS'S for this setup. I figured I would need 44 cells as a minimum storage bank. Can you tell me about how many watt hours you think each 22 cell 48 battery will provide. I think this is the way to go as I don't want to worry about cold weather. I don't know why you are crimping and soldering after as I have been told by my electrician friend to only do one or the other as it can cause a current restriction for some reason. Tell me why you need to do both ?

[@DavidPozEnergy]

As for the crimp and solder, I just figured "It can't hurt". I don't have a good reason beyond that. These cells are 20 ah, Nominal voltage of 2.3v. Roughly 46 wh per cell. So just multiply by how many cells you are using. I'm using 22s, or about 1 kwh per 48v battery. I'm grouping 4 together, or about 4 kwh by the time I'm done.

[@fisherus]

@@DavidPozEnergyThanks Dave. I just spoke with my electrician friend about why you shouldn't solder after crimping a contract point. He said that because the solder doesn't penetrate the wire throughout it can cause resistance in the current. The resistance converts to heat possibly causing a fire. As I have very little knowledge in this area I felt it best to heed his advice. You seem to be the expert but I wanted you to know what he said. Is there anyway possible that you could put a diagram of your BMS wiring on your Facebook page?

[@jylimports]

do you know where ca I find this lto batteries?

[@HomesteadingintheForest]

Hey David, I have a question regarding the length of wires from the batteries to the bus bar. My understanding is that it’s really important for the wires to be the same length. How does having the BMS interrupt the negative wire alter the length of the wire? I’m wondering if all the positive wires are the same length, what should the negative wires be (positive wire length minus the BMS wire length?)?

[@DavidPozEnergy]

We are talking about paralleling batteries to one central point (bus bar). The goal is to have all the battery circuits be equal resistance. The circuit includes the cells, BMS, wires, terminals. If you have two or more batteries connected to the same point, and they have the same resistance, then the load will be shared equally between them. However, if the resistance is different, then the load will be different. Usually we say "keep all the wires the same length" because it's just an easy way to make sure all the resistances are generally the same. This matters if you have a load larger than one battery can safely supply. You don't want to over-heat one battery.

[@HomesteadingintheForest]

@@DavidPozEnergy Ahhh, I think I get it. So as long as all the negative wires are the same length and all the positive wires are the same length (could be a different length than negative wires) then the resistance will be the same on each battery circuit?

[@DavidPozEnergy]

Close, the total length of wires should be the same for each battery. (positive wire length + negative wire length) You could have a 3' wire on the negative, a 2' wire on the positive giving you 5' total. Then the next battery might be arranged different and you have 1.5' on the negative, and 3.5' on the positive. Still 5' total.

[@HomesteadingintheForest]

@@DavidPozEnergy Thanks for the explanation. Very helpful as always.

[@solarsystem3918]

Which type of cable you use in Soler panels to charge controller please tell us. Please

[@DavidPozEnergy]

My solar array is connected to my charge controller with 6 gauge copper, THWN. I have a video on it here: kzbin.info/www/bejne/qmaxk6yPfLVnmLc

[@solarsystem3918]

thank you very much david

[@jkrienert]

@DavidPoz : Any chance you have the maximum outside dimensions of one 8S module?

[@DavidPozEnergy]

Sure. 4.02"x10.44"x7.00" However, I measured using a measuring tape, not a caliper so I might be off a fraction. The height of 7" is to the top of the rubber grommet.

[@jkrienert]

@@DavidPozEnergy 'Shockingly' fast reply, and the tape based measures are great. Thanks!

[@ninehundreddollarluxuryyac5958]

Whats happening with the LiFePO4 power tower? Is there going to be a BMS or a different active balancer? Or are you bottom balancing and monitoring voltages? Is it powering your house yet?

[@DavidPozEnergy]

Once I get these cells up on the wall I'll have more space to move around. I have to pull the LiFePO4 modules and add thicker balance wires. I want to get back to that as well. I'll be sharing all of it.

[@davidcollett4037]

Is it true that LTO Battier's can be discharged 30,000 times

[@DavidPozEnergy]

Hi David, According to the manufacturer, "exceeding 20,000 charge/discharge cycles," www.scib.jp/en/about/index.htm

[@OrionHCCC26]

@@DavidPozEnergy are you familiar with Yinlong? I just completed a partnership with them and will be the only licenced distribution company in the USA, if you Are ever in need of any type of cells from yinlong, message me on here because I have not yet launched my website.

[@kchiem]

Where's Part 2?

[@DavidPozEnergy]

Sorry, there is no part 2 yet. This project got pushed down the list when I changed inverters and other projects.

[@icarus901]

David, which vendor did you contact for the BMS?

[@DavidPozEnergy]

Daly Electronics Co. LTD. I sent them my first e-mail through aliexpress. On the lower-left side of the page there is a "contact" button. www.aliexpress.com/item/32955265431.html?spm=a2g0o.productlist.0.0.3f5879fbEYtbxb&s=p&algo_pvid=c16801c4-25b8-418f-a3ff-023d6f5f2fd0&algo_expid=c16801c4-25b8-418f-a3ff-023d6f5f2fd0-0&btsid=6ff9ffa4-2502-4d43-af6a-2149a420dbe1&ws_ab_test=searchweb0_0,searchweb201602_10,searchweb201603_53

[@henrymensah2883]

@@DavidPozEnergy where to buy the LG batter for DIY.

[@teknomadix5822]

Next time. Don't hold the solder joint IN the torch flame. Hold it .5" - 1" away from the visible blue flame. Also, place the joint in a vise, and hold the torch. That way you can move the heat on and off the joint quickly, and control the heat much better. You will have no scorching or issues with wire sheath catching on fire. Instead of wrapping with flux core solder, coat the wires in solder paste before inserting each end into the crimp.

[@DavidPozEnergy]

Thank you for the tips.

[@teknomadix5822]

@@DavidPozEnergy Love what you're doing. Keep it up!