diy solar

diy solar

LiFePO4 100ah advice in EU

kahlheins

New Member
Joined
Apr 26, 2022
Messages
6
Looking for a 100ah to 150ah LiFePO4 12V battery for use as an auxiliary battery in a campervan. It will be used with a double-battery management system and a Victron MPPT charger. It should be no larger than a standard DIN sized car battery (190 mm tall, 175 mm wide, 353 mm long).

Some of the branded ones (Victron, etc.) are just far too expensive. Is there any cheap chinese alternatives that you can recommend? Some of the frequently mentioned ones (chins) don't seem to be available in Europe.
 
Thank you for the links! Would love to hear if someone from the forum has some experience with these or similar models.
 
What about GWL Battery? They seem to be heavy in Winston prismatics - maybe something you can diy?

I see some smaller pre-builts that might be worth considering.
 
curious, after a 12v self built battery I might be in the market for a pre made 24v setup.
Needs to have low voltage cut-out. Also wil consider building myself again if that seems better.

Really love my JBD 4s BMS
 
So, I received the battery and I am very confused.

Firstly, my CTEK CS ONE charger does not recognize it properly, and only allows supply or recondition mode when connected.

Secondly, I just measured to voltage on the battery after charging it for ~ 7 hours with the charger that came with it. The voltage briefly shows as 14.8V on the multimeter, and then quickly climbs to around 15.7 V within a few seconds with the multimeter connected.

I assume there is something wrong here?
 
@kahlheins
OMG - STOP RIGHT NOW !! SERIOUSLY - TWO possible issues

It would be a miracle if the internal BMS saved this battery from *either* one of those chargers.

Looks like you out-smarted the "smart" CTEK. Like you know that the no-polarity leads actually ARE polarity sensitive when overriden with either the wake-up or supply modes.

Like most lead-acid options, the desulfate / recondition mode applies 16v pulses in an attempt to create cracks in sulfation to at least get some sort of charge started. In addition, they can also try to supply a much higher CV like 15v for those nasty dead car batteries. Don't use those!

Are you *really* going to risk it all on some "APTO" algo, which *might* mistake your LiFePO4 for lead acid? Who ya' gonna call first?

Power supply mode goes only up to 13.6v, which will not be enough for your internal balancers to do their thing.

Simply put, there are PLENTY of simple 10A , 14.4/14.6v LFP chargers that remove all these smart variables that can trick a non-battery-nerd by combining lead-acid features with LiFePO4 in one charger.

One of which is also temperature-compensation - used for lead, but NOT for LFP!

Also, what you have described makes me wonder if the *other* charger they included isn't one really intended for 24v or higher, and they made a mistake by supplying it in the box.

I'm bummed - you may have inadvertently fried your brand new Kepworth.
 
Only connected the CTEK charger for a few seconds when the supplied charger had already "done its magic" and the problems were already there. The charger is supposed to output 14.6V according to its label, so I assume the charger isn't at fault.

The battery will probably go back to the seller.
 
What country are you based. I can give details for UK sellers of good quality drop in batteries .

Mike
 
What country are you based. I can give details for UK sellers of good quality drop in batteries .

Mike
I'm in The Netherlands.
I've found a shop on Ali (TPO Technologies Store) that seems to have an acceptable reputation and can provide a 24v 200Ah battery with a JBD BlueTooth bms.
Will compare that against building my own
 
I'm in The Netherlands.
I've found a shop on Ali (TPO Technologies Store) that seems to have an acceptable reputation and can provide a 24v 200Ah battery with a JBD BlueTooth bms.
Will compare that against building my own
Hey, did you buy the battery from Ali? If so, what is your impression of it? I'm in a similar position to you.
 
nope i ended up with 8 of these:


good stuff. added a JDB bms.
 
nope i ended up with 8 of these:


good stuff. added a JDB bms.

how experienced are you in electronics? did you find it easy to build?
 
Back
Top