Progressive Dynamics charger/converter for 2 Trojan T-105’s

OEM roof connector can be changed, re-wired or abandoned altogether.

Likely #12 wire factory-installed.

5 choices then:
run 2 panels,
change wire to #10 and run 3 panels,
change both connector and wire (#10 again) and run 3 panels,
abandon connector and wire, run your own MC4 #10 through fridge vent without connector, uninterrupted all the way to controller - with 3 panels again.

Choice #5 for those who have to have parallel panels: abandon OEM connector, install roof junction box.

Probably more solutions.

I wish they didn't install those 2-pin connectors on the roof.

I'm stopping by dealer tomorrow to talk with the folks who install the solar on rigs such as mine.

Will get the wire specs needed to make decisions.

Just ordered a Victron Solar MPPT 100/30.

Question: If I get say a single 355 watt solar panel regardless if it's 24 or 36 volt the MPPT I just ordered will send up to 30 amps to my 12 volt Trojan T-105 AGM batteries correct?

I'm thinking around 25-29 amps going to the 12 volt batteries.

Does this sound right?

Thanks.

Almot wrote:
Choosing MPPT controller is the very last stage, after deciding on battery bank and array size - how many of those 24V panels and how many watts each.

Change the light bulbs, meanwhile. I'm not kidding. Mex is right, for boondocker this is not optional.

Bulbs are LED's. Thanks for the persistence you're right!

I did order a 100/30 MPPT because I know I'm going to have roughly 350 watts at 24 or 36 volts going into a dual Trojan T-105 AGM 12 volt battery bank.

Yes that 355 watt panel feeding a Victron 100/30 will put up to 30 amps into your battery.
Sheet says up to 440 watts so get a little bigger is OK too.

time2roll wrote:
Yes that 355 watt panel feeding a Victron 100/30 will put up to 30 amps into your battery.
Sheet says up to 440 watts so get a little bigger is OK too.

Oh good thanks.

Wanted to make the right decision going with the 100/30.

What if wanted to add 2 additional T-105 AGM's for a total of 4 same 12V voltage.

Would I need bigger MPPT?

You only need a larger controller if you have more solar wattage.

time2roll wrote:
You only need a larger controller if you have more solar wattage.

Dumb question then can I double my solar wattage to say 36v 700 watts and still use the MPPT 100/30 controller?

Thanks.

2oldman wrote:

Rail Dawg wrote:
What is the recommended voltage for the solar panels?.

I'm not sure there is such a thing. In my case it was determined by the #10 wires from the roof to the basement. They will max out at about 360w at 12v. I have 835w.

Watt limitation on solar wiring? I've only heard of the 30A limit on 10ga and 20A on 12ga. Always presumed that was good up to 100V, the usual mppt limit.

brulaz wrote:
Watt limitation on solar wiring?

At different voltages, yes.

Rail Dawg wrote:

time2roll wrote:
You only need a larger controller if you have more solar wattage.

Dumb question then can I double my solar wattage to say 36v 700 watts and still use the MPPT 100/30 controller?

Thanks.

The controller will limit power to 30 amps.

You would have to get a higher rated controller or go 24 volt on the battery to pass through 700 watts.