question

samsonodunola avatar image
samsonodunola asked

Synchronize multiple devices charging one battery bank

I have a quattro 48/8000/110 linked with a fronius primo8.2, a smart solar MPPT 150/100 solar charger and a blue solar MPPT 150/45 solar charger all connected in parallel to a battery bank(48v, 16units x 110ah).

The problem is all the devices connected to the battery bank are charging the batteries at different rates. for example if the blue solar charge controller is in float mode, the smart solar charge controller will be in absorption mode while the quattro will be in bulk mode.

I have put the same charge setting(float:55.2, absorption 57.6) for all the devices but it dosent seem to work. I also activated the DVCC setting in the color monitor but it dosent solve the problem either.

MPPT Controllers
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

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

1 Answer
snoobler avatar image
snoobler answered ·

A couple things going on:


1) The three charge sources all have different resistance between them and the battery. This means that even though the battery voltage is the same for all three, they may "see" a higher voltage and be in a different phase of charging.

2) Each source's "strength" may dictate how they react. Generally speaking, the strongest charge source (highest amps) will finish LAST.


DVCC on the GX can regulate the maximum charge current from all GX connected devices, but they can't "sync" and all be in the same phase. It makes sense that the Quattro is in bulk, the Smart is in Absorption and the blue is in float as this may be the order of "strongest to weakest."


To my knowledge the only way you can "sync" solar MPPT is with Smartsolar units in a VE.Smart network.


You can eliminate/minimize #1 if you have a BMV as the shared voltage source. If you don't have a BMV reporting OCV to the system, each charger sees the battery voltage rising due to the charge current.

2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

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