question

Tom Ranson avatar image
Tom Ranson asked

3rd party charge controller how to prevent over charging

Hi all,


Grid parallel

Cerbo GX with ESS with DVCC

MultiPlus ii

SmartShunt

2x MPPT 100/30

24V battery bank (8x 6V FLA in series/parallel)


I'm planning to install a second Smart Shunt configured as a DC Energy Meter in-between my system and a 3rd party MPPT charge controller. This will allow me to see this charge source in VRM.

However, given it is a dumb 3rd party controller which cannot integrate with the GX, what do I need to do to ensure that I am not overcharging the battery bank from this charge source? I'm concerned that on a high generation day that the GX will throttle back the Victron chargers, but obviously the 3rd party dumb one would just carry on generating...

Many thanks as always.

cerbo gxchargerSmartShunt
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1 Answer
JohnC avatar image
JohnC answered ·

Hi @Tom Ranson

With unmanaged FLA's, the mppts (both Victron and Other) should continue on attempting to reach their own V setpoints. The only reason for the GX (DVCC) to throttle them would be to Limit Charge Current.

With your "second Smart Shunt configured as a DC Energy Meter" this will also be taken into account by DVCC, and the Victron mppts would presumably be throttled back to honour the Limit. Providing the Other mppt's output isn't above that Limit, then all should be sweet.

I haven't tried this myself, so you'll need to test it.

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Tom Ranson avatar image Tom Ranson commented ·
Many thanks @JohnC this makes a lot of sense. If I really want to play it safe I suppose that I could implement a current limit via DVCC, which would only affect the Victron MPPT's, so as to provide headroom if the 3rd party source is putting out a high charge rate.
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