question

cdj avatar image

Setup of BMV with Victron AGM batteries and solar

Hi all,


can’t seem to find any info in the victron data sheets on their own AGM batteries what the Peukert value should be, and in general how the BMV should be set up to accommodate for solar.

I have:

2x100Wp solar on roof

1x220Ah AGM Victron battery (new 10 august 2020)


and am looking for the correct settings for my BMV to correctly display SOC (as good as possible anyway). Can anyone help?

BMV Battery Monitormppt smart solar
2 |3000 characters needed characters left characters exceeded

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

3 Answers
nickdb avatar image
nickdb answered ·

Plenty of threads about this topic already.

For Victron batteries you shouldn't need to adjust the Peukert settings.

As per the manual, you need to set the charge voltage for non-solar environments to 0.3V beneath float. For solar they suggest 0.3V below absorption, but a midpoint between the two seems to be better.

Adjust your tail current, defaults are too high. The advice I got was 2% for the lead acid batteries but I did find that a little high and dropped to 1.8%. Extend the the time needed from the default so it doesn't trigger too soon. I use 8 minutes, works well enough.

2 |3000 characters needed characters left characters exceeded

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

JohnC avatar image
JohnC answered ·

Hi @Cdj

There's a Peukert calculator here: https://www.victronenergy.com/support-and-downloads/software

Victron seem to always recommend (for Pb batts) start points of 95% Efficiency and 1.25 Peukert. The BMV should have those as default. If your SOC is drifting one way regularly over the daily cycles, then adjust the Efficiency to compensate. Mine was drifting down (floodeds), and needed 90% set to tune that.

The default sync parameters are too 'liberal' for me. Maybe set your Charged Voltage 0.3V lower than the mppt float setting, and the Tail Current to 2% (or even lower, I use 0.7%).

There's other less important stuff which could usually be left at default. The BMV manual is a good place to start to help understand it all, and there's no substitute for close monitoring and tuning where necessary to get to the point where you're confident in the resultant SOC.

Good luck..


1 comment
2 |3000 characters needed characters left characters exceeded

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

It’s 0,3V below Absorption...

cdj avatar image
cdj answered ·

Thanks you both! I put it on:

tail current: 0.7% (1,54A)
charged voltage to 13.7V (0.1V below float of the AC charger and MPPT charger)
95% efficiency
Peukert 1.25
We'll calibrate from there...

2 |3000 characters needed characters left characters exceeded

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.