question

stevej avatar image
stevej asked

AGM batteries, MPPT100/30 solar 330W panel, bmv712

Hey guys. Totally new here


I have a rough under standing but after realising how much these Victron products can do it’s gone way over my head

So I have 2 12V AGM batteries, 1x 105A, 1x280A linked together for one big 12V system in my caravan

I’ve got a 330W solar panel with the Victron MPPT 100/30

And now just put the BMV-712 battery monitor


I’ve just purchased the Bluetooth dongle for the solar regulator.

When it comes I’m just wondering if I can get some advice to what I should set all the parameters up on,

At the moment it’s charging at 13.8V which is the base setting I believe in the regulator but from what I’m now finding out it should be up around the 14.8V

so if anyone has some specs that I should upload for the solar reg once my dongle arrives that would be awesome


Thanks guys

BMV Battery MonitorBluetoothSolar PanelAGM Battery
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1 Answer
JohnC avatar image
JohnC answered ·

Hi Steve.

You'll likely find that the factory defaults in your mppt are something like 14.4V Abs and 13.8V Float (+/- temp compensation). The 13.8V you see now may indicate it's in Float state. So possibly all good as it stands.

Except you have a bigger issue than this.. Two vastly different batts in parallel are likely to cause imbalance issues between them, and will impinge on their longevity. You may notice firstly a difference in temp between the batts, and if this happens, read it as a prewarning of batt failure.

If you insist on doing it like this, maybe drop your charge profile down to (say) 13.8V max overall, to treat them more gently. And offer up a prayer to the battery gods (the Devil is in charge there)..

Take care Pal.

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stevej avatar image stevej commented ·

Thanks mate for the quick reply. Yeah okay I might look into dropping the 100ah out then or putting a switch in and keep it as a back up then.

Thanks heaps mate sets my mind at ease a little

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