2, 6 volts or 2, 12 volts

[Ready2gonow]

I have 2, 4 year old 12 volt marine batteries in my 5th wheel. I use no inverter, and have the factory Intelli- charger converter charger. I believe 9920 series. I usually am hooked to shore power, have a 2k generator, no solar. I plan on more boondocking this summer. I checked voltage this am at 12.8v. Unplugged from power, left a few led light s and frig on propane for 6 hrs. Rechecked voltage and it was 12.4, and slides and lights were working fine. Rehooked to 50 amp power and batteries read 13.7 v

Are my batteries still sufficient? If not, will 2, 6 volts be more efficient than my 2 12 volts of about 200 amphrs? Guys at Interstate battery told me 6 volts are longer to charge. Is that correct? Will my charge wizard fully charge 6 volt batteries? I have read on this forum that a higher voltage is needed to fully charge 6 volts. Most advice is appreciated.

[Almot]

2*6V = 225 AH. In my books this is already better than 2*100 AH.

Some 12V batts - AGM in particular - hold voltage under load better than flooded 6V. Doesn't sound like you're considering AGM, so go ahead with 2*6V. Not that you have to replace them now.

"Higher charging voltage of 6V"? Sellers don't always know the products they are selling, not to mention products they don't carry. Check the specs. All batteries are different, some higher, some lower.

"Takes longer to charge"? Flooded batts have lower recommended charging rate than AGM, but this is true for all flooded. I doubt there is much difference in charging rate btw 12V and 6V flooded.

[Ready2gonow]

Thanks for the replys. Did not know about the plug in Wizard, good idea. I thought my info about the 6v charging slower was wrong. SG is good in all cells, I maintain them regularly. I think I will keep them for now, and if I have problems with too much discharge, I will go with the 2 6v over the 2 12v. Always good info on the forum.

[azrving]

12.4 probably isn't bad. You mentioned hearing about six volts requiring a higher voltage. trojan is one company that says 14.8 charge. I use group 27 batteries in an electric boat and one of them is now doing it's 9th year so it all depends on how they have been charged and watered. Do some mock boondocking. Unplug or driveway camp and see how your batteries work out.

[KD4UPL]

You're batteries are probably decent. 12.4 after several hours with a load on isn't too bad in my experience. However, this is a terribly unscientific way to determine anything.
In my opinion 2 6v are superior to 2 12v in just about any circumstance. Your converter won't know the difference. I'm not sure what you mean by efficient. You mean charge efficiency? It varies with all batteries but not enough to worry about.

[time2roll]

Ready2gonow wrote:
I use no inverter, and have the factory Intelli- charger converter charger. I believe 9920 series.

Do you have the Wizard?



http://www.progressivedyn.com/charge_wizard_9105.html

[Golden_HVAC]

Ready2gonow wrote:
I have 2, 4 year old 12 volt marine batteries in my 5th wheel. I use no inverter, and have the factory Intelli- charger converter charger. I believe 9920 series. I usually am hooked to shore power, have a 2k generator, no solar. I plan on more boondocking this summer. I checked voltage this am at 12.8v. Unplugged from power, left a few led light s and frig on propane for 6 hrs. Rechecked voltage and it was 12.4, and slides and lights were working fine. Rehooked to 50 amp power and batteries read 13.7 v

Are my batteries still sufficient? If not, will 2, 6 volts be more efficient than my 2 12 volts of about 200 amphrs? Guys at Interstate battery told me 6 volts are longer to charge. Is that correct? Will my charge wizard fully charge 6 volt batteries? I have read on this forum that a higher voltage is needed to fully charge 6 volts. Most advice is appreciated.

12.8 volts under a slight load is a full battery.

12.4 volts is about 1/2 full. So I suspect that your 12 volt batteries are a lot weaker than when new.

The best I could get out of 12 volt batteries was about 2 years, so you are doing pretty good. Now my original Trojan T-105 batteries lasted 13 years, and the replacement set only 6.5 years because I was not as attentive at refilling it with water, so sort of my fault for them leaving early.

I would suggest a pair of 6 volt batteries, because they recover from being discharged much better, they have MUCH more water around the plates, and are not as likely to have a problem with debris that falls off the plates collecting below the plates and shorting out the cell - there is a lot more space under the 6 volt plates than the much more compact 12 volt battery design.

When I was taking a 30 day trip in my 85 class C, I had 3 deep cycle 12 volt batteries. 90 watt solar system, and dry camped as much as possible, recharging just about every other day while driving. Those batteries where worn out by the time they where 2.5 years old. That is when I traded in the RV. . .

I don't know why people say that 6 volt 200 amp hour battery bank takes longer to charge than a 200 amp hour pair of 12 volt batteries. I have found just the oppisent. I can put back 45 amps per hour when I started my generator, but as the voltage rises, it quickly drops to about 35 amps - according to my very accurate E-Meter. The larger battery plates can take a charge much faster, and are able to recover quickly.

Your charger will not know the difference between the large pair of batteries - it will charge it fine either way (6 volt in series or pair of 12 volt).

Have fun boondocking! Pick out a nice stream or lake and have a wonderful time!

Fred.

[gbopp]

Did you ever read The 12 Volt Side of Life?

[Ranger_Smith]

They appear to be but to really test them you need to have them load tested and or check the specific gravity in them.