8amp deep cycle battery plus coleman solar panels

[rv12volt]

hello i have a truck camper and i have a 8amp deep cycle battery i bought from cabelas online i use this to run my camper lights and run my fan and run my 5inch black and white tv i also have three coleman solar panels they are 4.5 watts each i have all three hooked into a 3 way hook up that is hooked to the battery now i know i dont need a controller for theses as they do not over charge but i wanted to know how long would it take for me to charge the 8 amp deep cycle battery with three solar panels if i put it on charge at 50 percent how many hours would it take to fully charge thank you

[johnjmw]

Hello and welcome. I'll try this with quicky numbers in an ideal situation.
3 panels at 4.5 watts = 13.5 watts.
+/- 4 hours sun a day (average) 54 watts
convert watts to amps divide by voltage 54/12vdc = 4.5 amp hrs a day
2 days minimum to recharge assuming no losses

John
ps I am going through this kinda stuff because I am hoping to install a small system I bought during hunting season.

[12vman]

Don't forget the 20% loss in the battery... * :-[

Each charge period will lose around 20% due to the normal losses in a lead-acid battery. Always figure at 80% of the total possible charge.

To Add..

The maximum discharge level should be kept at around 25% of the aHr. capacity of the battery. In this case, with an 8 aHr. battery, the working, safe "headroom" would be 2 aHr.

[johnjmw]

Ok,,, I was keeping it as basic as possible for a quick base. Thanks for the battery losses. I totally forgot about them. Though I didn't realize they were a full 20% That adds a lot of loss
John

[12vman]

" Thanks for the battery losses. I totally forgot about them."

I forget myself sometimes.. LOL

It can be a real issue on a small set up. It really shows over time if you calculate close.