Finished LifePO4 build (observations, cost, BMS, DC to DC charger

[kmcintyre]

Ok, I finished my LifePO4 battery build. Cost to build was about $435. I figured that it was just slightly more to build than buying another AGM and it'll last longer, work better. Main upcharge was the DC-to-DC charger.

Here's what I used:

4 LifePO4 cells; 12v 120ah LifePO4 cells (ordered via Alibaba from China where they all seem to come from). Took about a month to get them. Brand new, shipped was $180

BMS. There were a few options. Overkill solar sells one w/ bluetooth, etc. or you can order the exact same thing from Aliexpress (China) if you can wait about a week. $80 w/ bluetooth

DC-to-DC charger: I used the Victron TR-Smart 12/12 18a charger. $165

Misc. battery box, lugs, etc. $10

I also upgraded my portable solar charger with one that supports LifePO4 but that was an "incidental cost and was about $30ish. This is a basic solar panel.

It was fairly straight forward and will take it out for a test this next week on a short camping/fishing trip.

 

[buckland]

Have a good trip and look forward to hearing about the shake down cruise. If nothing else making your own makes you think about what is going on in your system and that is a good thing.

 

[kmcintyre]

Have a good trip and look forward to hearing about the shake down cruise. If nothing else making your own makes you think about what is going on in your system and that is a good thing.

It certainly has been a learning experience. Still trying to figure out all the correct charging profiles., etc. It wasn't difficult to build once you figure out what everything does and how it all works together.

 

[Vic Harder]

What is the total AH on your new battery? Can you share part numbers? I'm jealous the cheap shipping from China. Costs way to much to get to Canada!

 

[kmcintyre]

What is the total AH on your new battery? Can you share part numbers? I'm jealous the cheap shipping from China. Costs way to much to get to Canada!

Vic,

Here's a screen shot. Alibaba.com 120ah. You'll see the cell price @ @29 each (x4 = $116) and then the total with shipping ($188) so it wasn't that cheap and as stated, took a month (by boat). I did negotiate a bit with the seller on the cell price and I suspect you could too (I might have saved $10). Brand new cells. Make sure you get the bus bars although some people want thicker bars, they seem ok to me.

If you ever come down this way (Idaho), you could ship them to my house in Boise and then come pick them up at some point. LifePO4 will store for a long time (as you know).

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Shenzhen Senberry Technology Co., Ltd.

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3.2v120ah lifepo4 battery cell for RV/Solar system
Battery Type:Li-Ion,Nominal Capacity:120AH,Nominal Voltage:3.2V
USD 29.00 x 4


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USD 188.00
(initial payment USD 188.00)



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[Vic Harder]

thanks for the link. I may think about building one of these if/when it's time to build another camper (dreaming of a flatbed)!

 

[kmcintyre]

thanks for the link. I may think about building one of these if/when it's time to build another camper (dreaming of a flatbed)!

I've been dreaming of a flatbed too. I think the electrical demands might require a larger cell pack but it'd be an incremental cost and you'd probably have solar on the roof. I have been using a portable panel to charge my AGM but we'll see how this does on this trip. Still trying to figure out all the charger and BMS settings to optimize the battery life.