10kWh LifePO4 DIY Battery Addition..... Here is my write up.

How do you know then using a load tester when it's actually "empty", i.e. when to stop the test.

Plugged in the other one to test there, MM reading 5.3 when it starts running drops to 1.6

Nice one. Ya sorry getting all confused here. 3.5

Will sus out about the cutoff voltage.

Ya my issue is that I don't know what the true voltage is during a test. Drops way off as soon as I start the test.

This is also an expensive learning process for me I guess, not sure how to put the minimum setting in, also how does the device know what the true voltage is, does it stop every so often and check?

So I’ve put in the voltage etc testing again there. Problem is voltage drops below 2.6 if I increase the current over 10a??

does that mean the battery is knackered?

If the cell is fully charged when you start testing and with just 10A (or even the max 20A the tester can do) it drops almost straight away to 2.6V, then yes the cell is knackered.

I think you need to reboot the me3000 to clear that error. Connect it to a laptop and go in to the history log. Will see what cell alarmed low

Do you mean to connect the Seplos to the laptop to read its history log or connect the me3000 to a laptop? Don't know how to connect laptop to the me3000 except using the logger wifi.

When there is no load?

Well try bigger cables for sure, but those flimsy terminals on the tester can't take that much of a cable, been there, done that. Try to fit as thick and short a cable as you can. Also before you test, make sure your cell is charged up to 3.65V and taking no more current.

You guys know this space better than I.

While I know that tester maxes out at 20amp, I think doing a 50+ amp test and looking at voltage drop would be more appropriate. Assuming a 3kw draw (ME3000 limit) and 16 cells, your looking at 190 watts per cell. At 3.4v you'll need to be drawing down ~55amps to get that kind of power. It's a fair real world loading that the cell would experience and have to take.

Still though if the 20amp draw shows up issues, then no hope for the larger 50amp load I guess.

Makes me want to play with this stuff :-)

I'm 6P now, so about 800-900Ah usable given the CALBs aren't quite the full advertised capacity. While I can still see a voltage drop when people put a heavy load on (think kettle + oven + washing machine + rest of house), I no longer worry about it 😁

Hi Guys,

   Firstly, I hope it is OK to post this here but please feel free to move. I thought it was a bit relevant to this discussion. I've been following the thread for many months but I thought I'd try out the LiFePOs on my camper first before jumping in to a full home install as I already have a 5kW Soluna.

So based on the recommendations I ordered 4 x 200Ah CALB cells from PWOD. I also got a JK active balancer BMS from elsewhere.

So the cells arrived a week or so ago. One had brown stains on the base and some dust still in the crevices. It measured a bit lower in voltage that the other three out o the box. I charged them anyway and left them a few days on the balancer. We used it in the camper but the BMS shut it down with nominally 40% left. Damn I thought so based on here I borrowed a bench power supply and charged all four individually up to 3.65V and 0 current. I then put a 10Amp load on and took the voltage readings from them all every hour. The BMS shut everything down again at 35% with three cells reading very close to 3.15V but the other was down to 2.5V. So unless I am doing something very silly the cell is, as I feared, not great. 

I've been on to PWOD all week and they reply promptly but their suggestion to me was a link to buy a new cell. As it is single it is almost double the price I paid.

I will be disputing the order but was wondering if anybody had any advice about how best to do this? What language to use or points to note. I will then have to make a decision on whether to buy a single one or maybe just sell the 3 good ones and buy 280Ah for a bigger battery elsewhere if there is a market for 3 cells here.

Apologies for coming in to the thread cold with this and as I said please feel free to move or delete as appropriate.

Thanks, was away for a while, but I've reconfigured the cells as parallel and top balanced them, while at the same time I had disconnected the seplos cables and measured the resistance from each pin of the white and black seplos connectors to the ring terminal of each one. Note, I had soldered on extensions to the wires and then crimped the ring terminal onto that wire, so I was measuring the resistance of the original wire, the solder connection, the extension wire and the crimp ring terminal.

All of the wires came in at around .3 to .4 ohms, except one which came in around .8 to .9 ohms. So, I resoldered and got it to measure .4 Ohms too.

I reconnected everything back to 16s2p again and turned on the seplos with the laptop connected, and cell 1 was still reporting lower voltage than the others, and when I turned on the Sofar to discharge, it caused shutdown of the seplos again and gave the Low Voltage alarm in the Sofar again.

I saved the History Log, so hopefully that can help to diagnose the problem, it's available at

I'd appreciate any advice thanks.