My van has 5 x 140W solar panels. I started out wanting to wire them up in parallel, and produced the following plan -
I was quite set on my approach, but decided caution was wise, and so asked which was better from a loading batteries perspective - should I optimise for more amps, or more volts?
Tom made the most coherent argument I've heard -- which made me go with series after all -
In terms of the output of the MPPT, series or parallel doesn't really make a difference, because whatever is coming into the MPPT is then regulated by the MPPT to a steady, consistent 12V charge current.
So it's more to do with the input of the MPPT. Tom said he more often than not gravitates towards a series connection because you get the higher PV voltage (photovoltaics, i.e. voltage produced by solar panels), and that higher PV voltage translates to a longer charging window, so the 5V threshold that you need to be above for the MPPT to start charging is met much sooner in the morning, and is cut off much later in the afternoons/evening by that PV voltage being higher.
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