Thread: Dual batteries and solar

I don't know anything at all about the Redarc charging units, but having both batteries linked is definitely a problem as you risk finding yourself with a flat cranking battery and unable to start the vehicle. The main battery should be isolated from any accessories whilst the vehicle is parked, so that you can run your fridge, lights etc off the auxilliary and have no risk of draining your main battery. A 120w solar panel should easily keep your fridge running, if the weather is favourable it will put enough charge in the aux battery during daylight hours to run the fridge around the clock plus some low-current lighting in the evenings. We did this on our last top-end trip with one 80w solar panel.

You may well find that your Redarc system links the two batteries whilst voltage is above a certain threshold, then isolates the main to protect it from being drained below that threshold level.

Originally Posted by Jacko44

The regulator is set up for 50 /50 and for lead acids which I have. But I am assuming both battery's are now linked? It certainly appears this way on the monitor? Question is, is this a problem?

Really appreciate advice as I have a trip planned and I want battery's to last!

can you explain the 50/50 a bit more..........am i reading it right that from the solar regulator you are running solar charge to both batteries? you would have to check that your regulator will not allow charge to flow from one battery to the other at night (well drain charge from your start through your regulator over night)......your redarc should keep the batteries seperated

i normally only run my solar to the aux battery and leave the start to fend for itself.....well actually my dual battery system keeps both batteries connected til a pre-determined voltage than it drops the start battery so while the sun is out both batteries get charge than they seperate at night and only drain the aux battery

I am a bit of a amateur so I will try: I think the redarc solenoid stops the cranking battery from dying it separates the two when the cranker gets low. The redarc solar regulator allows me to change the charge each battery (both batteries are wired in) so I can go 90%/10% or 80/20 or 50/50 etc etc