question

darius avatar image
darius asked

Charge level difference between Victron MultiPlus 3k and Enerdrive ePro Battery Monitor

Hi,

I have a MultiPlus installed in a van with 4x150AH (in 2x2 configuration) batteries and an Enerdrive ePro battery monitor (it monitors the voltage and the current via a shunt resistor).

There is also a Record BCDC2420 which charges the batteries from the car's alternator while driving but for most trips this is fairly minor.

It seems that the MultiPlus goes to float early and so the ePro doesn't consider the batteries fully charged unless it's not being used for several days.

Previously there was a Giant IPS2400W inverter and it charged the batteries fully (according to the ePro) eg

https://www.dons.net.au/~darius/vanlogger/graph-2018-07-30.svg

https://www.dons.net.au/~darius/vanlogger/graph-2018-07-31.svg

(Although I see a step in the 31st - not sure if that's the ePro going "close enough" or something else)

eg https://www.dons.net.au/~darius/vanlogger/graph-2019-05-13.svg shows it after the weekend - fully charged at the start but it never gets back to 100%. At the end of the week it's like https://www.dons.net.au/~darius/vanlogger/graph-2019-05-17.svg ie reporting ~85% charge.

I can resync the ePro easily enough but I am wondering if that is the right answer, or if there are some charging options in the MultiPlus I can tweak (I am getting a VEBus cable soon). I would expect the ePro is more accurate than the Victron because it has a shunt meter.

I have a rough schematic at https://www.dons.net.au/~darius/Inverter-Wiring.pdf

Note that the cables between battery and inverter are short (<1m) and high gauge (not sure exactly but approximately the size of my thumb).

Any help much appreciated, thanks.


Multiplus-IIbattery charging
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2 Answers
wkirby avatar image
wkirby answered ·

It's quite possible that the MultiPlus charge parameters are not set the same as your old inverter charger, so the charge profile is different and doesn't conform to the charged detection profile of your edrive.
Let's wait until you have the cable then at least you can set the MultiPlus charger up to be the same as your MPP was and take it from there.

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darius avatar image
darius answered ·

Yes, I don't really know what the old charger (in the inverter) did though - it was a black box to me.


In the end I changed the charge curve from "Adaptive + BatterySafe" to just "Adaptive" and it charges more like I expect now.

I was a bit nervous about changing it given the name however...


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