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Can I Parallel up these to charge this?

swvic_matt

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Mar 10, 2021
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Hello.

Just looking for some help with my proposed setup.

I've decided to use 2, foldable panel arrays to recharge the vehicle mounted lithium batteries in my camper.

I'm wondering about the physical connection of the two arrays and MPPT controllers.

Can I simply get a Y cable and plug 1 array into 1 part of the cable, the 2nd array into the 2nd part of the cable & the other connection into the input of an MPPT controller? Will that work?

Or do MPPT controllers have multiple inputs? so I wouldn't need a Y cable? Or do I need two MPPT controllers?

Sometimes I'll only need 1 array to recharge with, other times I'll need both, so being able to simply plug & unplug will make that easy.

I'm thinking of using 2 x 170Ah Renogy lithium batteries in parallel and 1 x Renogy Rover Elite 40A MPPT controller.

The Renogy battery says it has a maximum charge current rating of 85A.
The panels have a Voc of 22.3V and Isc of 14.62A

Thanks for any help & suggestions.
 
Y cables are exactly for this purpose.

Your MPPT can tell you how many you can place in parallel and or series.
(It's maximum amperage and voltage)

Usually the foldable panels aren't high capacity, and most MPPT can do +1000 watt.
It should work fine.

Probably both series or parallel.
(Depending on the Mppt)

I haven't seen 10A MPPT, lowest I know of are 30A.

Yours is 40A, and the panels are -15A.
In series it stays 14.x A, with as benefit that it have higher voltage.
Parallel still way under the 40A.

I don't know the starting voltage for your Mppt, it could be that series is better.
 
Or do I need two MPPT controllers?

Separate controllers for each panel is optimal but uncommon outside extreme scenarios like sailboats, since those controllers have to cope with intense and variable shade patterns. For folks in RVs and similar running them in parallel with the Y into one controller would be fine (and normal). As fhorst says, running them in series with no Y would also likely be fine and would save the cost of the adapter and be slightly easier to plug/unplug (one set of plugs instead of two if the panels are left connected to each other when stowed). The manual says the Rover has a max input of 100v and two panels in series (44.6v) won't get anywhere near that. It's conceivable that the panel manufacturer disallows serial connection for some reason; I'd check the panel manual for that info.

For fun and profit I'd get the Y and test with them in series vs. parallel to see what works best for you in various situations. Parallel might be best if the panels have uneven lighting (shade, facing different directions), and serial might have some advantage in low levels of even light. The difference might be so slight you end up going with what's easiest for you.



The panels have a Voc of 22.3V and Isc of 14.62A

For my own curiosity, these are ~250w folding panels? Like a solar blanket or something?



I haven't seen 10A MPPT, lowest I know of are 30A.

I have a 10A epever MPPT for portables and as the back-end for a DIY converter. I have owned a 5A Genasun MPPT before (back when they were hand-writing serial numbers on the units), and they still make a 4A MPPT. Morningstar makes a 15A MPPT.
 
Thanks very much for the help, it's greatly appreciated.

Yes, @fratermus the folding panels are just 2 fixed panels in a frame that fold together to pack away.
 
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