LiFePO4 Battery Bank Build

[@mbirth]

Ah, the famous IEEE 1 connection.

[@bentleyjarrard885]

Great video, I completed a 48V, 120AH solar storage battery a few months ago and was surprised to find out during my research the absolute lack of any BMS systems that are a complete solution with regard to full protection for OVoltage, UVoltage, OCurrent, UTemp, OTemp along with active cell voltage balancing of at least an amp and some type of communication interface like Wi Fi and/or Bluetooth. Most of the systems either have no communication interface or are CAN based. There are products on ebay and Alibaba but many of them are "inline" type BMS systems meaning that the full current passes through the circuit board, I don't trust that arrangement so went with a ZEVA BMS that has an external shunt & relay outputs to control a high current mechanical golf cart type contactor. I then added an inexpensive 1.2A active cell balancer board. Set up and monitoring is done via CAN bus with a color touch screen. I have a friend working on a possible interface module based on Raspberry Pi with a CAN shield expansion board so I can get the BMS info onto my home network.

[@dejayrezme8617]

Interesting, I'll have to look into zeva. I'm thinking of building a 48V battery for a solar powered cruising boat. So a different type of electric vehicle with a large solar roof. What are your thoughts on going from 48V to 12V or 240V for appliances? 48V seems to be the max "safe" voltage and also not too messy BMS. And if you buck down to 12V or 24V at the "outlet" you should have less power loss for your wires.

[@bentleyjarrard885]

@@dejayrezme8617, I agree with you that 48V is really the maximum safe voltage to be working with for the average person, not to mention that many components designed for DC are rated at 48V by the manufacturers so selection of higher voltage DC devices is limited and expensive. You are correct about power loss on wires being reduced with higher voltage (this is more of an AC issue with transformers) BUT Buck/Boost converters are somewhat inefficient so whatever the gains are at 48V probably would be lost at the Buck stage. I have several ebay buck/boost converters for charging individual cells etc. they get HOT with only a few amps. There are low voltage appliances such as refrigerators available but they are expensive. My advice is to go with a either a 24V or 48V battery system then pair it up with a GOOD, EFFICIENT, HIGH END Inverter (Magnum Energy for example) then you can use relatively inexpensive, off the shelf appliances, LED light bulbs etc. that are available anywhere you go.

[@bentleyjarrard885]

@@dejayrezme8617 One last thought, if you do wish to use your system for operation of a small RV Air Conditioner unit then having the high voltage AC from an inverter is the best way to go. There are "soft start" modules available that limit the in-rush current on start up so your inverter is not overwhelmed. I'm using a Hyper Engineering device on my 4 ton condenser at home. Seems to work well but I have not tried to run it on my Schneider Inverter that is rated for 8500 Watts.

[@offgriddreaming5403]

Looks good. The only thing I would change is having the cells tight together so you can clamp the whole pack to stop any expansion 👍🏻

[@AdamWelchUK]

Yeah this has been mentioned, and truth be told I wasn’t aware of this. I’ll look into this and decide how to move forward. It’ll mean redoing my connectors though I imagine. Cheers

[@twotone3070]

@@AdamWelchUK You could put more of a kink in the straps to make them shorter if needed, bend them over a bit of 20mm conduit. Are you planning to grease/vaseline the final connection as you assemble them? We certainly used to do this with 50V bus bars in tele exchanges.

[@dejayrezme8617]

@@twotone3070 What is the grease for? Insulation? Anti corrosion? I was wondering if you could paint them using some kind of silicone or "liquid electrical tape" or something.

[@twotone3070]

@@dejayrezme8617 It was for anti-oxidisation. It was cheap, simple and effective, no need for a 'modern' alternative. You just need to stop oxygen from getting to the part.

[@Martinko_Pcik]

If you heat the copper up red hot and throw to water, they will become much softer and easier to work with.

[@electronic7979]

Good idea 👍

[@dboekel]

Hi Adam, Brass / SS / etc. doesn't matter as long as you use a bit of grease, but I'd advice normal (cheap) galvanised steel hex bolts, with Nord-Lock washers. the bolts you showed first also have a tendency to break of the head when torqued properly. all cell terminals, but especially the aluminium terminals: sand them 'clean' then immediately clean / apply some grease: aluminium grows a corrosion layer -very- quickly, and this is insulating, you have to clean that of, the grease keeps away oxygen so prevents re-corroding. copper busbars + aluminium cell terminals: severe galvanic corrosion....again: apply grease and problem is prevented (you can use fancy 'no-ox-id' grease, but most grease will do (Vaseline is fine) another tip, busbars: you can use aluminium strip / bar, very cheap, very good, don't use anodized as that has a thick non conductive oxide layer. also: sand before use, apply grease. Aluminium has 2/3 the conductivity of copper, so if you go 50% thicker you have the same resistance as a copper strip. Lastly: compression: it's best to use these cells compressed, as they tend to swell over time, swelling= less capacity etc. = not good. Nice cells that will last you a long time if you do it right.

[@AdamWelchUK]

Thanks for the tips. I’m going to redesign and clamp the cells together - a few people have mentioned this. I’ll look into grease too. Cheers.

[@andredejager3637]

Battery bank envy is the 8th deadly sin, and I got it bad

[@clintoncoker6]

You should give it a crack running it for a while without active balancing! The 4s2p pack I made (from admittedly much smaller 26650 cells) has never needed balancing, and I've had that running for over a year... (Obviously still need overcharge/overdischarge protection)

[@jamest.5001]

Isn't it nice to be able to get out and build something, even if it's something simple! What's the power situation with your house? Any solar for it? Any battery backup? Any plans for any?

[@RaithUK]

With those bus bars you will have plenty of current capacity through them.. thats good, 4s-3p so its a 12 volt system that makes it easy to find an appropriate BMS for it.. or in your case make one :)

[@AdamWelchUK]

Well you know where this is going... :-)

[@DreStyle]

Not British... Just a normal date 😂😂

[@sortofsmarter]

Very excited to see you do this. I have been on the fence about purchasing the same batteries and building a large battery storage array with a whole house solar system. I like the cost vs the nissan leaf cells and hated trying to use thousands of 18650's. look forward to your next video

[@brucestarr4438]

I went with the 280AH aluminum cased cells. China has a Glut of LFP cells right now. They were for their cheaper EV cars, which the market for has tanked.

[@McTroyd]

Is that the cell array replacing your lead-acid cells? Looking forward to the BMS.

[@AdamWelchUK]

That’s the plan!

[@thunderstrike66]

I couldn't remember who your voiced reminded me of.....until now.... Robin Leach! :)

[@pulesjet]

Given your soggy environment the Brass Bolts is a good Idea I think.. Here in the Desert S.W. I would have just used the Stainless Steel without second thoughts. The Dry contact wouldn't be a galvanic issue.

[@AdamWelchUK]

Soggy? I’ll have you know the north of England is not soggy! ;-)

[@Tinker001]

@@AdamWelchUK Just really damp... right?

[@pulesjet]

@@Tinker001 LOL, While in the USAF I was lucky enough to get parked in North London area for some 5 years. It as SOGGY more then not. Coming from the Desert South West USA I started molding. I have 24 Lion Brand Prismatic about like your cells. I need to figure out a means to create a mold to shape some bus bars like yours. No Printer at hand. I found a source for the bus bars, Flippen Ell there proud of the things. Like $5.00 each.

[@jontscott]

Don't the cells need clamping force on the sides to keep them from bulging over time? Or does that not apply to LiFe cells?

[@AdamWelchUK]

That’s something I will look in to. Thanks for the tip.

[@ME-cb1vw]

Yes, as far as I know.

[@AdityaMehendale]

IHHHI uses the same amount of copper as IEEEI, but will have substantially higher ESR - assuming that the busbar-ESR is dominant (which it likely is not). Nonetheless, good to see the optimization :).

[@NiHaoMike64]

Probably the most cost effective would be thick bus bars on the ends and within a string, with thinner (14 AWG or so) wire tying each level together to maintain balance. The balancing current between strings is very small. (For that reason, if using bus bars between strings, put those above the string bus bars so the high current path goes through fewer copper contact points.)

[@alexu5329]

Hi there. What are you going to use for charging?

[@AdamWelchUK]

The sun! In more detail I’ll be using just two 50 watt monocrystaline panels on a EPEver Tracer A MPPT solar charge controller.

[@Chickey]

Rather jealous of the new battery bank! We’re you not tempted to do the inter battery connections in a figure 8 rather than E?

[@AdamWelchUK]

I’m not convinced it’s needed, but I’ve spare pipe to complete that if I’m wrong. As it stands all the paralleled set terminals are all tied to a common point. . 18881 rather that IEEEI!

[@MiniLuv-1984]

@@AdamWelchUK I'm with you on the 18881 vs 1EEE1 Adam and, like Colin, jealous, very, very jealous. :) So, while I'm dreaming I'd go for a 1EEEEEEE1 .

[@JonathanWellskcender]

I say go for symmetry and make it an IE83I configuration. Haha

[@twotone3070]

@@JonathanWellskcender Ummm yeah, beautiful palindromic qualities.

[@jamest.5001]

My latest is a 7s set of LG 60 ah cells, in 2p, they are new, and I have a tub full of 8ah lipo cells, I'm figuring on how to parallel them!

[@stevedutcher3875]

Very nice!

[@DreStyle]

Parkside stuff is being used by everyone now 😂 I have a bit set that lasts even longer than the milwaukee bits! They are shocked at my work Its so funny that we all see now that you don't need an expensive brand for quality

[@DIYTechRepairs]

Correct. its no need to fuse those cells internally. Just a main fuse is enough.

[@rcboosted]

What is the reason? 18650 pack builders use individual fuses for each cell. Is it because lifepo4 are safer?

[@AdamWelchUK]

Cheers

[@AsadJamal78]

Hello Adam , i am having an issue with Epever Mppt controller , in cloudy days the controller is doing PWM as u mentioned in ur videos but there is a problem happening on load side of the controller bec of pwm it will flicker the load side which can be noticed by eyes on leds lights can u have a solution for that bec i powering my load directly from controller load side. . love ur videos keep the good work.

[@SuperVstech]

IEEEI haji approves... frightened, but approves.

[@brucestarr4438]

FYI, for long term storage of LiFePO4 cells or batteries, they're best stored at 40-60%. Storing them at or near full capacity can seriously degrade the cells. It's different if you're actively using them.

[@AdamWelchUK]

I planned to do this much sooner, but things got in the way. Thanks for the advice though :-)

[@RWBHere]

13331 - Who'd have thought that it would top out at 13,331 milliVolts? !

[@AdamWelchUK]

I had it turned round the wrong way!

[@PatricksDIY]

2:06 not to be a downer, but when you use "smashed" copper pipe, you are creating more resistance, unless it is perfectly flat. it can even cause arching, excess heat etc. Great videos, been binge watching them all night. I spoke up about this because my inspection failed due to trying the same thing with copper pipes, the inspector said the above to me. It may be different where your from.

[@gerardjachymiak5822]

Is that drill solar powered?

[@AdamWelchUK]

Yes - I charge it from an inverter from either my 12 or 24v systems. :-)

[@Magic-Smoke]

Ooh Adam. This will be interesting! Most of the other banks I’ve seen have been configured as 4 groups of 3 parallel cells to keep the 3p groups at the same voltage. I’m wondering how cell balance will keep up since, wired this way, under load the groups of cells are not forced to the same voltage. So which cell will you monitor in each group or do you intend to monitor every cell? (Although I seem to remember you have a 4 channel bms).

[@clintoncoker6]

? All the cells in each parallel set are commoned with bus bars. What are you referring to?

[@clintoncoker6]

This *is* 4s3p.

[@MrThomBeck]

Charlotte Lackney this is the correct configuration. Parallel cells match their voltage to the cells they’re in parallel to.

[@ME-cb1vw]

We built large Batteries out of this and other LiFePo cells. All were delivered including busbars (the small ones) and stainless steel screws.

[@AdamWelchUK]

Stainless steel screws - oh well, I’ve got the brass ones now.

[@RaithUK]

@@AdamWelchUK the brass ones do indeed have less chance of galvanic corrosion specialy in humid outdoor environments with large temperature swings.

[@andrewpatterson5349]

Wonder if anyone can help me please? I have a 12v solar system made up of 4x 12v 75ah batteries wired in parallel, I have jusr bought a new charge controller and it requires me to input my battery bank capacity, do I put 75amp or 300amp?

[@AdamWelchUK]

Wired in parallel you add up the amp hour rating - so you’ll have 300Ah.

[@andrewpatterson5349]

@@AdamWelchUK thank you Adam, I kinda thought it would be but just wanted to make sure. Love your vids, very informative and entertaining. Stay safe and take care, kind regards Andy 😎

[@AdamWelchUK]

Cheers Andy. No bother. You stay safe too.

[@tsKroony]

Does anyone know a reputable source for these in Australia, international shipping is prohibitive.

[@patrickmclaughlin6013]

Excessive to have a bus bar between the negative posts as well as the cross over bars?

[@AdamWelchUK]

I’m happy that the negative of each set is commoned together using the positive of the lower set - but I can always knock some out if required. It’s not excessive I don’t think, but possibly not needed either. I’ll take feedback on that.

[@Peter_S_]

Were it me, for high discharge I would even add three more series bars to the "E"s keeping the single parallel bus along the negatives but also add a single bus along the positives and then double up on the bus bars on the ends. This serves two or three purposes, (a) you can never have low enough resistance and in high current work you typically find lots of thick bar stock with more mass than that pipe, and (b) the highest resistance part of these strings is going to be where the bars and posts meet and those places will heat the most under heavy discharge so by having more copper there it also works as a heat sink/spreader. Copper is great that way. (c) There is also the benefit that if a string develops a bad cell, the others will still be able to contribute via those bus bars. The cross section of a single water pipe I could see as medium duty depending on the pipe thickness. In the US, we've got three common grades of hard copper for water use and the good stuff you can direct bury in the dirt is about 75% thicker than the cheap indoor pipe. Finally, crushing the ends in the vise after drilling and then coating the contact surfaces with some silicone grease should make this setup perform every bit as well as one costing much more.

[@bren106]

Lidl workmate, they're a cracking bargain and I'm glad I picked one up. Best tenner I've spent for a long time.

[@AdamWelchUK]

It works for me too! I have a lot of Lidl tools and diy gear. Too tempting those middle bins.

[@briancarney4609]

Why did you not shrink slave bars first then open holes in plastic for more protection

[@AdamWelchUK]

It’s a good question. I need to look at how I could achieve that - the cells have quite large terminals at the top so I’d need to cut a sizeable hole. I’ll see how I could achieve that. Thanks.

[@judo-rob5197]

A newbie question: Why do the bars used in series have a bump in the middle?

[@Martinko_Pcik]

I'm guessing it is because of the rim on those batteries seem slightly higher than the electrode and prevents the flat piece to be used. Just a mechanical hack.

[@jimthvac100]

It looks like your 18650 battery pack is 24 volts. Curious why you don't buy four more of those 65AH batteries and then use all 16 to make a 2P2S 24V battery pack instead of the 3P1S 12V you just made. Then you can use the same 24V inverter. or Just build a 1P2S 24V pack and use the extra cells to make a smaller 12V for something else.

[@alzdeane]

Interesting build, however the music on the time-lapse parts is both too loud and annoying!

[@cmuller1441]

It's not IEEEI it's 13331... You are watching from the wrong side 😅

[@AdamWelchUK]

Ah. How stupid of me. ;-)

[@iantsears]

IEEI - Institute of Electrical and Electronics Engineers - en.wikipedia.org/wiki/Institute_of_Electrical_and_Electronics_Engineers

[@juanantoniotierno4328]

Estético de baterias es mejor que las baterias chinas eve 280 lifepo4 gracias

[@ayyadew]

IEEEI

[@richardtallian5156]

IEEEI