10 most common solar misconceptions busted by solar industry gurus!

3. HOW DO YOU WIRE UP A REGULATOR WITH A DUAL-BATTERY ISOLATOR?

Q: If my 4WD is running and charging my auxiliary battery via cables through a voltage sensing relay, will I cause any damage to any equipment if I then plug a regulated 12v solar panel onto the auxiliary battery and leave it connected? Is it okay to be connected to the same terminals as the cable from the primary battery? Can I send too many amps back to the solar panel and cook it?

If the solar panel regulator and panel has appropriate protection to stop current flow back through the regulator and panel then there is no concern of this. This protection is common as even a charged battery connected to a regulator and panel that is in the shade/dark would have the same effect of passing current through the system if there was no protection.

The more important point here is to ensure that the panel charging the battery at the same time as the alternator does not impact the vehicle system, for example if the regulator output voltage is higher than the vehicle charging system intends – in late model vehicle with “smart alternators” this can upset the vehicle by seeing unexpected high voltages when the alternator is trying to decrease the voltage. In these instances it is recommended to have the solar regulator output turn off when the vehicle is on. Ideally you would connect the regulator output to the auxiliary battery side of your VSR in order to go to the auxiliary battery if the VSR is off, rather than the primary battery. The CTEK D250SA Coupled with the CTEK Smartpass 120 can manage the flow of power from your solar panel directly to your starter battery or auxiliary battery and is compatible with smart

4. WHERE DO YOU FIX THE REGULATOR?

Voltage drop is a very real and common issue with all types of 12v electrics, and solar is no exception. Along a five metre cable run, it’s not uncommon to see half or a full volt of voltage drop. What makes this even worse is heat – as in, the heat from the sun needed to run the solar. All this conspires against your solar setup, but you do have a trick up your sleeve you can use. Always, wherever possible, mount your regulator as close as possible to your battery. That way, the voltage drop will occur in the segment of cabling that’s unregulated, instead of the bit that has been regulated. In other words, it’s much better to experience 1v of voltage drop that takes the 20v or so the panel produces and delivers 19v to the regulator which drops down to 14v anyway, than it is to take the 14v that the regulator outputs and drop it down to 13v to the battery.

To be continued…