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spidvej avatar image
spidvej asked

Charging 12v battery with MPPT connected to top battery up

I have failed to find a clear answer on this, so hopefully someone can shed some light please. I have a simple setup - 140w panel connected to a Victron MPPT 100/20 charge controller, connected to 1 12v AGM battery - all the loads I use are via the MPPT load port (just to charge phones, ipads, sometimes have a 300w Inverter etc). I do not power anything directly off the 12v AGM battery terminals. If there's not enough daily solar and battery voltage becomes low, can I simply top up the battery using a regular 12v car battery charger, connected directly to the battery terminals? Do I need to disconnect the panels from MPPT controller, and then disconnect the battery from the MPPT before charging the battery to top it up? I do not want to damage my Victron MPPT controller..

Many thanks for any advice!

battery charging
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3 Answers
mvas avatar image
mvas answered ·

The simple answer is ... YES, you can connect a secondary charger to your AGM battery.

If you need more details then you can consult with your local Victron Dealer.

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spidvej avatar image
spidvej answered ·

Thank you mvas - I will try it :-)

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Bob K avatar image
Bob K answered ·

Yes, you can connect the MPPT charger and the second charger to the battery simultaneously. Both are designed to read voltage and current into the battery to determine the appropriate charge profile. As the battery voltage climbs during charging, both devices will modify their charging profiles simultaneously.

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