[AmelYach,tOwners] Observation on using 12v Lifepo4 batteries in serial/parallel (probably applicable to lead, too)


Stefan Jeukendrup
 

Interesting and unexpected observations gentlemen,

This could simply be a little non liniarity or a  bit of offset in the Victron voltage measurement circuits:
you are only talking about 0.28V max. (0.24V is 1% of 24V)

Your good quality multimeter has probably a similar accuracy. Use that to check the voltages as a comparison for more consistent results.

The most important thing is that the individual cell voltage measurement in the internal BMS is very accurate as that switches off the passive/active balancing.

Hoping this is helpfull,


Stefan Jeukendrup
Sv Malaka Queen
SM2k #348 @ Newry, Northern Ireland



Op 4 jun. 2022 09:57 schreef Dean Gillies <stella@...>:

Hi Scott,
Well there you go. I don't understand the mechanism whereby the bottom battery is consistently lower voltage.
Sounds like an interesting conversation with Victron.
Keep us posted on what they say.

Out of interest I just checked my old notes from AGM batteries when I was looking at balancers a few years ago. I had 6 strings, and 4 of them had the TOP battery at higher voltage and 2 had the bottom battery at higher voltage. As I type, my Lead batteries are showing the TOP battery as being higher - see pic.

--
Dean Gillies
SV Stella *****,  Amel 54-154