DIY Lithium

st3v3

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Hi Folks
First ever post in ANY forum!
Built this Li-ion battery to power my electrified Brompton and "electric scooter" (I know at 72 I should know better). 30 Samsung 30Q 3000 mah 18650 cells @ around £2-65 each from Fogstar in UK. Configured 3 parallel and 10 series = 9A x 37v but obviously can be arranged in any which way eg. 7p x 4s = 21A x 14.4 V. The Razor scooter is a wolf in sheep's wooly stuff, with the Li-ion and bigger motor it zips along at errrmm !! Now fitted with disc break ! So is this info of any use to you guys considering a battery build for your vans?
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Neat. What do you think the total price is, with all the hardware etc?
 

Philip Tomlinson

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Did you make any progress with this Phil?
They have not arrived yet as they were sent overland rather than sea because of Brexit uncertainties. I am expecting an update tomorrow.
I have now seen several videos from people who have purchased the same cells and BMS from Basen and are very happy with them.

I am not going to rush to install them, I want to top balance them and do some capacity tests for youtube. I am also considering compressing the cells to increase their lifespan, so I am researching that at the moment.
 

Brockley

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looking forward to that Phil, I’m now quite looking forward to building a few Lifepo4 batteries for fun and perhaps a few mates looking for upgrades.
 

SquirrellCook

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They have not arrived yet as they were sent overland rather than sea because of Brexit uncertainties. I am expecting an update tomorrow.
I have now seen several videos from people who have purchased the same cells and BMS from Basen and are very happy with them.

I am not going to rush to install them, I want to top balance them and do some capacity tests for youtube. I am also considering compressing the cells to increase their lifespan, so I am researching that at the moment.
Glad you mentioned this Phil, I hadn't ever heard of top balancing and compressing. The top balancing doesn't seem too bad, though by reading some peoples experience can be long winded. As for compressing the cells there seems to be lots of ideas. Most of them using the stud and plate idea are just squeezing the edges. I'm guessing for this to work best you'd need to apply pressure evenly on the sides of the cells. A rubber sheet between each cell would help, but still how to apply an even pressure over the face of the end cells?
 

xsilvergs

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A rubber sheet between each cell would help, but still how to apply an even pressure over the face of the end cells?
I have considered 3D printing a spacer with ventilation ducts to improve cell cooling.

For the end caps I think the main force needs to be at the center of the cell face as I guess this is where most of the expansion will happen.

Am I over thinking this?
 

SquirrellCook

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I have considered 3D printing a spacer with ventilation ducts to improve cell cooling.

For the end caps I think the main force needs to be at the center of the cell face as I guess this is where most of the expansion will happen.

Am I over thinking this?
If my limited understanding is correct, it is to control delimitation of the cell structure under heavy load conditions. So any point loading is to be avoided.
 

xsilvergs

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If my limited understanding is correct, it is to control delimitation of the cell structure under heavy load conditions. So any point loading is to be avoided.
It wouldn't be a point loading I was aiming for, but a force at the corners wouldn't help.

I imagine a piece of 12mm ply the size of the battery face. Pushing at the center of the ply would be more beneficial.

I feel a sketch coming on.
 

Harryw

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They have not arrived yet as they were sent overland rather than sea because of Brexit uncertainties. I am expecting an update tomorrow.
I have now seen several videos from people who have purchased the same cells and BMS from Basen and are very happy with them.

I am not going to rush to install them, I want to top balance them and do some capacity tests for youtube. I am also considering compressing the cells to increase their lifespan, so I am researching that at the moment.
Ah just realised yours have not arrived yet, it must be over 60 days now? I ordered after you and was quoted 40-50 days overland. I’d better calm down on my expectation of receiving mine soon then.

I’m also rather hoping the DDP terms Basen shipped under are robust and the U.K. customs don’t get silly and ask for more!

looking forward to your updates...
 

Philip Tomlinson

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Ah just realised yours have not arrived yet, it must be over 60 days now? I ordered after you and was quoted 40-50 days overland. I’d better calm down on my expectation of receiving mine soon then.

I’m also rather hoping the DDP terms Basen shipped under are robust and the U.K. customs don’t get silly and ask for more!

looking forward to your updates...
I have been told that they will be in Europe on 3rd March and then DPD will deliver then with a few days. I was quoted 50-60 working days. (about 11 weeks0
There are lots of people on Youtube that have purchased from the same company so I am confident that I will receive them. We still have 6+ weeks before we can get out in the vans so I am not getting worried yet.

I have ordered batteries from China before and there was an additional customs charge which I paid and the company refunded me straight away via PayPal.

Phil
 

1 Cup

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Is that a 12v or 24v phil
Off-grid garage. ausy african bloke just had a melt down with his bms . At cell 11 and 6! 48 v pack lol
Another youtube got cells, metal box and bms, with temp from china in one pack.! but i didn't log the company alliexspress but he's in usa ! Think he spoke mandarin
They also gave him anderson plus fitted to crimped wire. Good bus bars nuts and alen bars.
Yes I will build my own 500 amp pack 12v. if some one has a alli account that has good reviews and want to buy in bulk I'm in.
 

1 Cup

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Is that one bluetooth and temp monitoring? Young Mr prowes likes them.
That relion is still in box. Lol
Batteries at work
What's your thinking on heat at low temps -0 ? So you can continue charging! I'm thinking heat from light bulds or water could replace heat pads for cell size !. Extra -The bus bar fuse gets hot running @ 1600 w !.
240v 1600w heater on at -19 wouldn't work on hookup with victron 5kw or 3kw

Anyone found out at what amps out, that the cells warm up on own at -20 to take them above +1
In use they mite be self warming ! Mite be a balance thereish?
 
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