DIY Lithium

Trotter

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New meds to lower my BP have given me hours of new free time to think about the state of the world, economy, life, the universe, and everything. I think the medical term is Insomnia.

DIY batteries? Of course very few people would have tried to construct a DIY lead acid battery. Bit on the iffy side that.
But with the amount of components available on eBay, Amazon and AliExpress. Prismatic cells, BMS, etc. I’m surprised no one on this forum has tried, or admitted to have built one. (AFAIK)
There’s more than enough videos on YouTube, by the likes of Will Prowse.
Time for someone to give it a go?
Not me of course, I’m still in Lee’s mindset. A two piece toolkit. Hammer and electrician screwdriver.
If a hammer doesn’t fix it, it’s electrical
 

maureenandtom

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2020-12-10_093453.png
 

wildebus

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New meds to lower my BP have given me hours of new free time to think about the state of the world, economy, life, the universe, and everything. I think the medical term is Insomnia.

DIY batteries? Of course very few people would have tried to construct a DIY lead acid battery. Bit on the iffy side that.
But with the amount of components available on eBay, Amazon and AliExpress. Prismatic cells, BMS, etc. I’m surprised no one on this forum has tried, or admitted to have built one. (AFAIK)
There’s more than enough videos on YouTube, by the likes of Will Prowse.
Time for someone to give it a go?
Not me of course, I’m still in Lee’s mindset. A two piece toolkit. Hammer and electrician screwdriver.
If a hammer doesn’t fix it, it’s electrical
Try checking out motorhomebuilder.com ;)

There is also a forum member that is running a (IIRC) 400Ah DIY Lithium Battery Bank in his Ducato based conversion and has posted info on either here or motorhomer.com along with a couple of YouTube Videos which are interesting to watch showing the process.
So .... yup, been done and is very doable (y)
 

Philip Tomlinson

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I am installing a 1120Ah LiFePO4 bank in my motorhome soon. This is made of 16 x 280Ah 3.2V EVE prismatic cells and 4 x Daly 100A Bluetooth BMS. The cells fit into the battery trays that I already have, in fact, they are 3cm shorter. Later next year I am going to add heater pads to the cells and a charge flow control system.

I would like to give you the exact price but at the moment it is uncertain because of upcoming changes to customs and trade agreements so I can't order them until the 2nd January and the USD exchange rate may have changed by then. The parts cost including the busbars, BMS, Bluetooth module, cells, shipping, customs clearance and VAT comes to $2158 USD (£1622.93) which is less than £1.50 per usable Ah.

You could of course just order 4 cells and one BMS which would cost £410 for a 280Ah battery.

Compare these two:

280Ah DIY LiFePO4
cost £410 (280Ah 100% useable) £1.46 per useable Ah. 3000 cycle life X 280Ah = 840,000 Ah delivered @ £0.49 per thousand Ah delivered

Varta LFD90
cost £90 (90Ah 50% useable) £2 per useable Ah. 200 cycle life X 45Ah = 9,000 Ah delivered @ £10 per thousand Ah delivered


THE CONS ARE

That you have to deal directly with the manufacturer in China through a website like Alibaba.
Although the parts may come with a warranty I would not fancy trying to make a claim.
You need to make sure the cells are charged to the same level before connecting them together.
You will need to build some kind on an enclosure for the battery.
The battery will not have a low-temperature cutout.
With prismatic cells, the max discharge current is normally the same as the capacity, so a 280Ah battery may have a max continuous discharge current of 280A.
If you want to run a big inverter (mine pulls 400A) you will need to make sure that the BMS is big enough to do so.
You will still need to survey and maybe upgrade you charging systems for the requirements of LiFePO4.
You do need to have some electrical competence to do this.

Phil
 

bmc

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New meds to lower my BP have given me hours of new free time to think about the state of the world, economy, life, the universe, and everything. I think the medical term is Insomnia.

DIY batteries? Of course very few people would have tried to construct a DIY lead acid battery. Bit on the iffy side that.
But with the amount of components available on eBay, Amazon and AliExpress. Prismatic cells, BMS, etc. I’m surprised no one on this forum has tried, or admitted to have built one. (AFAIK)
There’s more than enough videos on YouTube, by the likes of Will Prowse.
Time for someone to give it a go?
Not me of course, I’m still in Lee’s mindset. A two piece toolkit. Hammer and electrician screwdriver.
If a hammer doesn’t fix it, it’s electrical
OK Derek.....I'll have to admit it. I built my own in February following Will's video. 100Ah with Calb cells from China.

BMS with low temp. cut-off and bluetooth . App on phone gives all the info you would ever need.

Bought a new 160watt solar panel to go with it, and a Victron controller.

Very happy with it so far, but obviously haven't used it in anger yet as I've been in lockdown all year.

As long as your aware of how dangerous batteries can be, and take ultra care with your tools it's very doable.
 

Trotter

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Best of luck to all who try this. Having just fitted new lead acid to mine, it’s unlikely I’ll ever get round to doing my own. Although I have every intention of being a nosy sod in future to anyone who’s done their own.
 
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