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diy solar

diy solar

First time cell purchase, looking for advice!

bigforrap

New Member
Joined
Sep 6, 2023
Messages
11
Location
CA
Link: Gotion 314Ah 3.2V prismatic
Other links: Blog, Youtube

This is the quote I received:
Gotion 314Ah LiFePO4 cell (32 cells) + DDP = US$2,039

Nothing comes close to giving me 30kwh at that price. I’m wanting to put them together into a 16S2P configuration, 48V in my RV for full-time boondocking. Potentially expand to 16S3P in the future if needed. Axle weight is more of a limiter at that point haha. I will be installing two JK-PB2A16S15P (150/300A), one for each 16S. Sized to allow each S-string to fully supply the 5kw inverter in-case one BMS goes down. Inverter limited to 4kw on BMS (existing RV wiring limits).

I've been lurking in the forums, I know Docan can be hit-or-miss. This is my first foray into DIY solar, and my first large purchase. I’ve been doing my own research for weeks, but I’m at the point of information overload from watching long Youtube reviews (that I'm so grateful for).

Questions:
- What should I realistically expect from these "A-minus cells" performance-wise. I'm not looking for capacity perfection, but also don't want bloated/damaged cells.
- Should I order extra cells, or an enclosure (planning on simple fabric-tape compression), or a proper battery charger for initial top balancing?
- It comes with busbars, is there a minimum thickness I should request?
- What should I ask for re the cells/shipping? The quote does not include any test reports.

Holistically:
It’s my first time, I don’t need perfection. I’m going to have fun putting these together and learning more about DIY batteries. I want to learn how to test cells and monitor their performance over time. But I mainly want to hook up into my RV, and hit the road, and don’t want to spend 3 extra months arguing with a seller.

Thanks for any advice!
 
I've ordered both and see very little difference. I have five batteries built and in service using EVE 230 amp cells. Three are "EV Grade" and two are "storage grade" cells. I use Overkill branded JBD BMS's which have no active balancing and my delta above 3.5 volts per cell is less than 10mv on all of them.
 
Similar here.
From Docan
2 packs - Eve 230Ah "Grade A"
1 pack - REPT 280Ah "Grade B"
36 more REPT supposed to deliver
today.
From 18650
1 pack - Envision 395Ah "Grade B".

All play nicely together. The EVE's were the only ones I top balanced, 2 years ago, before assembly.
 

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Similar here.
From Docan
2 packs - Eve 230Ah "Grade A"
1 pack - REPT 280Ah "Grade B"
36 more REPT supposed to deliver
today.
From 18650
1 pack - Envision 395Ah "Grade B".

All play nicely together. The EVE's were the only ones I top balanced, 2 years ago, before assembly.
Looks like you just snuck in before they ran out of everything except 230Ah.
 
There must be a lot of battery builders in the lower 48.
24 of the 32 REPT I ordered from US stock came today, the rest come tomorrow. Don't know why the shipment got split, but it doesn't matter. The order I placed with Docan for China stock cleared customs the other day and will be here next Tuesday. Another 48 REPT. Should be good for at least 12 months at this point haha.

The overseas shipment is a case study in why you use DDP. I have no idea what they paid to import. And I want to keep it that way.
 

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