Charging auxiliary batteries
- Thread starter fg4oz
- Start date
blackduck
Explorer
Ben I just run a 120w folding panel for the truck
it keeps my 120Ah AGM fully charged with the 80L weaco and all the lights running of it no problem
westyss
Explorer
Driving around the batteries stay charged for the most part but when static it becomes a problem with a constant draw. I found that once the batteries were drawn down to 50% or so, driving for hours would not get the batteries fully charged even though they appeared to be fully charged if that makes any sense?? Before solar I had trouble keeping the batteries up and sometimes would find a place to plug into mains and use the Iota charger to get them up and floated into fully charged then be on my way, now with the solar I dont even plug into mains at home, the solar keeps them fully charged and equalized all the time.
There are many on this forum that know solar well and I am sure you can get lots of advice from them but in general make sure that whatever solar you get match the needs of your batteries.
I have almost 500 watts of solar and for my consumption , battery bank size, and time typically static in one spot and general location (as in how much expected useable light in your general area), but you in a different solar enviroment would most likely require less panel wattage than me for the same consumption and set up. For many years I have abused batteries and killed them and now that I have researched them more I realize the need to match the solar to battery and provide a good charge to them to keep them going for a long time as that will be the most costly part of the system and the one that will expire the earliest.
J Rhetts on this forum made a really informative consumption data spread sheet that helped me design my set up and I have found that his numbers closely resemble mine. Get a good battery monitor too(very usefull info from that)
BTW, solar panels are so cheap now that going bigger is not much extra cost, a good controller is the next biggest expense and maybe design a bit of "add onto it" for future needs is usually a good idea, I have never heard of anyone reducing the consumption but have heard many add onto thier consumption.
dwh
Tail-End Charlie
Makes perfect sense. The battery voltage rises to the set point voltage of the voltage regulator. After that, it's just a trickle charge. The battery appears to be charged because it's at the "full charge" voltage - but it's just a surface charge and the battery still needs quite a bit of absorb time before it's actually full.
Because it just has a surface charge, after the trickle charge stops and the surface charge burns off, the battery voltage will be below the 12.8v that a fully charged battery would be at.