Axpert 3kva 24v inverter voltage

[Fiellies]

Hi

 

I just bought two 24v Leoch LiPO batteries from FNB to drop into my existing setup because my lead acids were no longer cutting it. (Thinking about it, it might have been the inverter acting up and not the batteries).

 

When connecting to the batteries via bluetooth they display 26.3V charge (both), when measuring the batteries directly with a voltmeter this matches (26.3V). However the inverter displays that the batteries are at 29.2V (which should be bulk charge), this means the inverter doesn't actually charge the batteries because the way I see it the inverter thinks they are full.

 

Now, question: Is there some setting I can do to recalibrate these voltages, or do some other magic? With a difference this large I guess the hope of the inverter still being salvageable isn't high. 

 

Pity because the batteries were trying to get around having to buy a new 48V inverter  

[Coulomb]

17 hours ago, Fiellies said:

However the inverter displays that the batteries are at 29.2V (which should be bulk charge), this means the inverter doesn't actually charge the batteries because the way I see it the inverter thinks they are full.

Yes, that much discrepancy is unusable, especially on an LFP battery where the voltage doesn't change all that much from nearly empty to nearly full (say 10-90 SoC).

17 hours ago, Fiellies said:

Now, question: Is there some setting I can do to recalibrate these voltages, or do some other magic?

No setting, but there is a little magic   Battery voltage calibration is the one that is most accessible to users, though the manufacturer don't exactly advertise it. It's discussed in this post; since yours is a lower power model, you may need the PBAT pair discussed right at the end. But I don't know much about the 24 V models.

https://forums.aeva.asn.au/viewtopic.php?p=71631#p71631

Note that there is an issue with the models that have a removable display. Does yours have this? Basically, the display acts as a giant filter, and doesn't send along some commands, including the most convenient ones for calibrating the battery voltage reading.

[Fiellies]

Much appreciated, I don't have the removable display. But will fiddle around with this.

 

Meanwhile I've ordered an even cheaper Mecer one to just keep going while I fix this one.