DC switching between 2x 100/20 controllers?

DIY
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1

I have 2x 48v batteries which need charging from 3 panels @500watts , via 2x 100/20 charge controllers, 1 per battery

I need a switch to select which cc is getting the solar charge on/off/on ?

this would be mounted between the cc,s and the panels .

There is not enough space to mount extra panels to supply each cc so they have to be selected when a charge is required for a low battery

This is on a boat withe a 10 kw electric motor in addition to 1x diesel engine , a hybrid .

2

Is paralleling batteries an option? Then the two batteries can be charged as one battery.
If this is not an option, you could use a change over set up, each mppt connected to single battery, solar array to 2no. Pv isolators connected to the two mppts. Caution - only one of the pv isolators can be closed at any given time or magic smoke will appear.

3

Thanks ,

I want to keep the two batteries separate for several reasons .

One being that connecting the two through the mppt cables will cause the dreaded smoke as cables are only 6mm2, which will mean high volts going back through the mppt,s and cannot handle 70v +

So I bought two mppt controllers , but can only spare space enough to charge 1 at a time , so a changeover switch will keep them separate .

switch has to be ON-OFF-ON to achieve this .