Community Forums

Yaaintdeadyet · 06-28-2009, 01:55 PM

I have 2 120 watt solar cells coupled to a 2500 inverter. This RV is in storage here in the southwest desert. With plenty of sun, I've kept my inverter active many times as it has always maintained a constant charge of 13.5v even with mild usage. As it stands now I left the inverter active over the course of 72 hours last week discovering on my next visit that my batteriers are now at 10v and not charging whatsoever. I checked the battery's fuses and they're intact. It's possible I'm missing something yet I haven't figured what it is to this point. Thanks for any direction in advance.

EngineerMike · 06-28-2009, 02:16 PM

First thing I'd check is your solar controller. The minimum controller is a couple of diodes so current will only flow one way from solar to batteries, and prohibit back-bleeding of voltage from the batteries to the panels which would otherwise occur at night. Some controllers are fancier. If you have voltage on both input & ouput of the controller, then there is likely a fuse between the controller & batteries if the circuit is well designed; you'll need to find & check that fuse.
Might also check panels for excessive dirt, and check the rooftop wiring that gets sunburned.

Yaaintdeadyet · 06-28-2009, 02:41 PM

Thanks Mike, I'll get back to the RV later this evening, after this 110 degree heat subsides. My controller is behind the panel above my fridge. An easy 4 screws hide the fuse inline with it. This is where I suspect the broken fuse exists. I'll post again with the results. By the way if anyone else has a tip please clue me in. I've got to admit I miss living fulltime in my RV. This sticks and stones lifestyle is nice yet there's just something about moving to a different view every so often.

wa8yxm · 06-29-2009, 12:38 PM

One comment..... I hope you are mistaken when you said "GEL BATTERIES" Gels for the most part, don't take kindly to deep discharge.

AGM's (Which many folks insist on calling GEL) seem to be much more forgiving.

Yaaintdeadyet · 07-02-2009, 10:07 AM

This issue was nothing more than a broken fuse that needed some light and glasses for 54 year old eyes to remedy. I appreciate your input Mike, yet wz8yxm what was your point? Not to matter, this central AZ sun has brought my "cells" up to their comfort level.

wa8yxm · 07-03-2009, 08:59 AM

My point (Since you asked) is that GEL cells are about the worst possible choice for RV's. and a Gel Cell run down that far likely will not recover.

Many folks mistake AGM for GEL.. THough there are many reasons you could confuse the two, for example you must mount a flooded wet cell right side up, same for most Maintenance Free wet types. but a Gel can be mounted on it's side or even upside down... Same with AGM.

The technology is quite different and the ability of the battery to recover from electrical abuse (Deep discharge) is much different (Better in the case of AGM) as well.

This makes AGM a very good choice for RV if you need a maintenece free type battery.