Keep It Simple Solar
- Thread starter FosterWV
- Start date
228B
Observer
Lead/acid battery charging tech has not changed. AGM likes a little different voltage setpoints. If you're living daily with solar, turn the voltage down, etc... He has written many updates, and for what we do here which is portable 12V energy, his stuff remains spot on.
Go lithium if you like, I'm sticking with lead acid for my battery bank for the foreseeable future. There's something for everyone.
2015 - THE TRIMETRIC 2030... PERFECT
2018... RULES OF THUMB IN SIZING SOLAR SYSTEMS
2019 - LITHIUM BATTERIES TRUTH
2020 - MEGAWATTS - MORE LITHIUM TRUTH
...for example
Go lithium if you like, I'm sticking with lead acid for my battery bank for the foreseeable future. There's something for everyone.
2015 - THE TRIMETRIC 2030... PERFECT
2018... RULES OF THUMB IN SIZING SOLAR SYSTEMS
2019 - LITHIUM BATTERIES TRUTH
2020 - MEGAWATTS - MORE LITHIUM TRUTH
...for example
FosterWV
Baller On A Budget
Hey Foster! Just read through your thread here and you did well for the money with your dual 6V/215 Ah batteries. Yes, wired in *series* you'll get one 12V/215 Ah battery bank. Use the appropriate wire gauge to interconnect them, and which AWG (wire gauge) you select will be the result of the 12V accessory loads you plan to use (look for their watts and/or amps rating).
As for solar, you can get roughly 6 amp from one 100W monocrystalline panel, but you must use at least 10 AWG wire for a short run to the solar charge controller, or 8 AWG for a longer (20'+) run, because the resistance along 20' of cable is a 40' distance there and back. And if you use solar, be sure to position the charge controller as physically close to the battery bank as possible, but be mindful of the batteries' outgassing when charging. Be certain to provide exterior air ventilation of the battery bank.
Learn how best to charge those batteries, first and foremost. Everything else is secondary. If you're not starting your day or your trip with a 100% fully-charged battery, you're going to be limited. This is why you want a good, basic solar setup in order to keep that battery at a healthy state of charge (and fully re-charged at least! once per week if not every day).
I am a student of Bob's, here. You will see me post this link often. I profit nothing, I only wish to help others realize a dialed house battery setup. Good luck.
The RV BATTERY CHARGING PUZZLE
Written in 2004 and continuously updated since. Last extensively revised December, 2010. If you found this by having somebody send you to it, you may not realize it is only one part of an extensive…handybobsolar.wordpress.com
Appreciate the detailed reply I will check out your link.
The new battery set up is definitely an upgrade. We can go 4 days no problem. This should suit us fine we typically only camp 3-4 days - long weekends.
While traveling 2-3 hrs it charges off the trailerplug basically enough to keep the fridge cold. When we get home I use a 15 amp charger to recharge the batteries, then it sets until we go again. And when camping where there electric I plug in the 4 amp charger to maintain the batteries.
Solar is something we might try if we ever camped longer
Thanks again.
Last edited:
hour
Observer
Shouldn't you be maintaining the batteries at home too, after you charge it up to full upon return? Not doing that + unexpected breaks in camping destroyed several of my lead batts
67cj5
Man On a Mission
Yep I agree, Also buying too many batteries trying to build an impressive power reserve might seem like a good idea but the effort involved in keeping those batteries meens spending 3 or 4 days a month cycling and Charging them back up to avoid buildup on the Plates. As I have to do every month while they are not in use.
????
FosterWV
Baller On A Budget
I could plug it in occasionally and use the 4amp on board charger to maintain them?
hour
Observer
I guess. I have a 10 amp charger with a different mode for maintaining which is significantly less current. Might want to make sure yours won't boil away the battery.
FosterWV
Baller On A Budget
I have this.... good reviews
NOCO Genius GENM1, 1-Bank, 4-Amp Fully-Automatic Smart Marine Charger, 12V Onboard Battery Charger And Battery Maintainer
Attachments
Last edited:
FosterWV
Baller On A Budget
Update.... Thoughts???
Charged the batteries with 15 amp charger until it turned off 100% charge 12.8V after setting 12 hrs.
Reset the Battery Monitor
Plugged in the onboard NOCO 4amp charger watching the battery monitor it kicked up to roughly 4A input. Then dropped to around 3A input then 2A and has been at 0.08A input since.
Per email from NOCO (Excellent Customer Service)
“The GEN charger will attempt to get the battery to 14.5V. Once it does it should go solid green (maintenance mode) and simply monitor that battery. Once the voltage drops to 12.5 +/- 2V it will start flashing green (optimization mode) to top the battery off.”
So if I understand this correctly it is trickling in less than 1 amp and should maintain the batteries with out damaging them.
To wrap up my original Simple Solar final outcome for my situation, two GC2 Batteries from Sam’s Club $89 each netted me 215ah and lasts 3-4 days. The 107 useable ah (1/2 charge) maintains our led lights, charges phones etc, runs the 1 gpm faucet pump, small fan all night, and 55L Fridge.
Hope this helps someone when determining if they need solar or a better house battery bank.
Charged the batteries with 15 amp charger until it turned off 100% charge 12.8V after setting 12 hrs.
Reset the Battery Monitor
Plugged in the onboard NOCO 4amp charger watching the battery monitor it kicked up to roughly 4A input. Then dropped to around 3A input then 2A and has been at 0.08A input since.
Per email from NOCO (Excellent Customer Service)
“The GEN charger will attempt to get the battery to 14.5V. Once it does it should go solid green (maintenance mode) and simply monitor that battery. Once the voltage drops to 12.5 +/- 2V it will start flashing green (optimization mode) to top the battery off.”
So if I understand this correctly it is trickling in less than 1 amp and should maintain the batteries with out damaging them.
To wrap up my original Simple Solar final outcome for my situation, two GC2 Batteries from Sam’s Club $89 each netted me 215ah and lasts 3-4 days. The 107 useable ah (1/2 charge) maintains our led lights, charges phones etc, runs the 1 gpm faucet pump, small fan all night, and 55L Fridge.
Hope this helps someone when determining if they need solar or a better house battery bank.
Last edited:
All good.
If you get a precisely adjustable charger in future, the CV / Absorb voltage should be at the high end of Deka's spec'd range
and hold there - not dropping to Float V - until amps trail down to that 1A (0.005C)
As the bank ages, it may never get there, so can substitute:
Current **change** over 1 hour period of less than 0.1A
If you get a precisely adjustable charger in future, the CV / Absorb voltage should be at the high end of Deka's spec'd range
and hold there - not dropping to Float V - until amps trail down to that 1A (0.005C)
As the bank ages, it may never get there, so can substitute:
Current **change** over 1 hour period of less than 0.1A
OllieChristopher
Well-known member
A simple solar charge controller and 50 amp panel is what keeps my batteries healthy when parked. Te beauty of the system is it's all automatic. just plug in the panel and forget it.
calicamper
Expedition Leader
I have a 8 yr old $20 20amp solar controller, on a boring lead acid battery. Two 10watt panels I set out and it has handled our LED lights and device charging for 8 yrs no problem, all contained in a 50cal ammo can bolted to our trailer.
If you can make it two nights guessing group 27 or 31 lead acid battery 80-100 watt panel and a basic $30 controller would be fine.