Two Batteries again

It’s surprising how much power we can use over a few days, the lamps used in most interior lights are 6W iirc so two of those consumes 1 amp per hour and if left on over a 24 hour period will take 24Ah out of the battery – a significant amount of energy to remove from a starting battery.

I have a rule that the interior light is switched to the “always off” position when I go bush in order to prevent me leaving it on by accident.

In regard to leaving the panel connected; if you have a smart charger/interface between the panel and the battery all will be well otherwise the panel will, probably, overcharge the battery and shorten it’s life. Careful no one pinches the panel in the city too!

Mike Harding

The 130 Watt solar panels are obviously regulated ??
So there's no problem powering the Aux battery system 24/7.

However, the Dual battery isolator system ALSO charges the Auxiliary battery system, so the Solar system in of little importance, because as you say there's no charge taken from the Auxiliary battery system, so no real or perceived benefit leaving them attached.


The point AGAINST having them attached far out weighs them being there...

Some one else may decide they want them :-(((

Hi chris

I have panels permanently connected through a regulator to my aux batteries on my truck - no problems - the panels are bolted to the roof.

The panels work well in conjuction with the alternator without trouble - no need to disconnect.

The two battery banks are connected with a redarc smart solenoid to protect the starting set from discharge - if you dont already have one fitted I would recommend that you fit a smart solenoid - doesnt matter which brand but I have had good service - 4 years so far from a redarc.

So that the starting set is always charged when the truck is standing in the yard for long periods I have three diodes conencted in parallel in a thickish lead between the aux bank & the starting bank positives - the solar panels keep the cranking set topped up as well (of course with a voltage drop for the diodes) - but they are never flat. The diodes are oriented to allow current to flow from the aux battery to the starting battery and not the reverse. The diodes are just the highest amperage schotkys (sp) I could get from Jaycar abt 8 amps I think. The negatives of the two batteries are also joined.

By the way a multi meter wont tell you much about the state of your battery as the difference between a fully charged and rested battery and one that is flat and rested is about a volt - good luck.

Hope this helps