New solar set up

jfowler

 New on this forum. Let me start by saying I am solar novice and building a camper van  and was gifted 2- 300 W 24 V solar panels.  Through my limited research I’m finding that 24v panels are probably not ideal for my application As I am using mostly 12 V appliances,however I understand I can use a MPPT charge controller to bring the voltage back to 12 V to charge my battery bank. I have 2-12 V 100 amp hour  lithium ion batteries and I am wanting to use a 12 V 2000w pure sine wave inverter/charger to  provide  AC power as well as charge batteries. I suppose my biggest question to start is is this configuration the most efficient  or would I be better off using 12 V panels or a different configuration?? 

Estragon

My first thought is whether there's space to mount the panels properly (assuming they're being roof mounted?).  300w panels are pretty big.

An mppt controller should be able to charge the 12v bank quite efficiently.  A decent mppt costs a fair bit more than than pwm, but if the "gifted" panels work physically, it may be worth it.  If not, 12v panels with a pwm controller would probably make more sense.

fratermus

jfowler said:

Through my limited research I’m finding that 24v panels are probably not ideal for my application As I am using mostly 12 V appliances,however I understand I can use a MPPT charge controller to bring the voltage back to 12 V to charge my battery bank.

In general 24v panels, mppt controller, and 12v battery bank will work just fine.  

There are a few MPPT controllers with very low input voltage limits (CTEK D250S or whatever) so do check the specs.  If in doubt link to t the items here and we will eyeball them together.

Dave

I use a 24V 200W panel with a sunsaver mppt 15 and a 12v battery (2 x 6v in series) and it works great but you'll need to make sure whatever controller you get could handle the current and voltage you're looking at. FWIW, my panels at home and on trailer put out a lot more than rated wattage when they're cold and get hit by direct sun and the battery is in need of charging, i.e. max demand and ideal conditions.