Need batterys.

[lawrosa]

Had 12 volt duracells DC 24. Served me OK. lasted 6 years. They were january 2014 matched pairs.Cell went dead on neg side battery

I Run 1100 watt inverter and do the coffee maker thing and toaster oven for the kids. I plug camper into inverter basically and turn off converter charger.

Boondocking was limited to weekends and overnights.

I do have 560 watts solar and 40 amp mppt.

I have a 2800 watt inverter gen Kohler.

I now have a cpap machine, and I also live in hot climate of myrtle beach.

I have all the boxes if I wanted to go to 6 volt.

I have PD converter 14.4 with wizard. Bigger wire to batts

12 volts specs on the duracell show DC24 footnotes 75aH

a) -low antimony grids
b)Deduct 15% from CCA and CA rating shown to allow for
double insulation (glass mat)
c)Deep cycle batteries also have
special fiberglass mats to improve deep cycling and long-life
performance.

I liked that I could charge these in less then 3 hours

6 volt duracell specs footnotes:::: 215AH

a)Low maintenance-low antimony grids. (same as 12's)
b)Peak performance capacity.
c)Premium glass mat reinforcement protects
battery’s ability to store energy


Heres my delema:::: ( And I never had 6 volters always dual 12's)


Im afraid to go 6 volt. Why? Voltage drop, resistance, long charging etc..

I can easily use perculator, and cook in the RV oven if and when I boon dock.

Im afraid I will not be able to charge them well or fast with the PD when boondocking. resistance.

Plus 13.6 volt is off a bit from what the 6's want. To equalize id have to pull out the old sears charger from 1982. 50 amp 10-2

My only reason leaning on 6 volts now it that last hurricane it was mass migration out of dodge. Camp grounds hard to find. The 6 volts would allow less worry possibly if I could not find a place to camp.

Are the new 12 volt batts different now? ( per the foot notes above?) Better?



Sams club has sale and I am buying this week. Two 12s $59 bucks a piece

Two 6's 89.98 a piece..

Note:: I am note buying any other battery then these two sizes. 75ah 24's or 215AH 6's. and I am only buying duracells. Please dont sell me on something else.

well interstae is down here. That would be a choice but for the price most likely not. and I hear interstates are just mish mosh of venders. Although the interstate 12's weigh 46.5 lbs. more then the duracells by 1.5 lbs..

Id rather hydrometer 6 cells then 12 cells too.lol getting old...

Thank you for your time..

Mike SC

[time2roll]

Nothing to fear but fear itself. The pair of GC2 will serve you well.

[lawrosa]

another vid. most of you remember these...

https://www.youtube.com/watch?v=wz2ttT8fFLc&t=77s

[lawrosa]

Painful to watch but now I know that left battery was on its way out. Thats the one that died. This was two years ago

https://www.youtube.com/watch?v=7p-oNT8YDIs

[lawrosa]

BFL13 wrote:

lawrosa wrote:

I am going with how you can run the big things on the 2000w inverter down to 75% SOC on two 6s before the inverter hits the 11v alarm with voltage drop, compared with how you can run the same load at 50% SOC if you have four 6s.

Ummm so let me ask. after such load is applied to 75% then 11 volt alarm goes off, what voltage do the batterys recover at??????

Exactly 12.375 🙂

ohh thats a big hit.. how many watts you run and how long? To 75%

[BFL13]

lawrosa wrote:

I am going with how you can run the big things on the 2000w inverter down to 75% SOC on two 6s before the inverter hits the 11v alarm with voltage drop, compared with how you can run the same load at 50% SOC if you have four 6s.

Ummm so let me ask. after such load is applied to 75% then 11 volt alarm goes off, what voltage do the batterys recover at??????

Exactly 12.375 🙂

[lawrosa]

I am going with how you can run the big things on the 2000w inverter down to 75% SOC on two 6s before the inverter hits the 11v alarm with voltage drop, compared with how you can run the same load at 50% SOC if you have four 6s.

Ummm so let me ask. after such load is applied to 75% then 11 volt alarm goes off, what voltage do the batterys recover at??????

[lawrosa]

BFL13 wrote:

prichardson wrote:
Sounds like you are worried about recharge time. Charge time is dependent on how much amperage has been removed from the battery bank. It does not matter if it is 2 12s in parallel or 2 6s in series. As far as the charger is concerned it is one big 12vdc battery.

You do faster time if you remove more! 🙂 By doing 50-80s instead of 70-100s (both 30AH)

But then your bank is lower in AH (higher R) while camping so voltage drop is more. Try to still have enough AH at 50% to run the inverter loads and do 50-80s for fast charging too.

That can mean four 6s instead of just two. And a bigger amp charger and gen to run it to still keep the time down. And a bigger Rv to carry the four batteries. And a bigger truck to pull it.

LOL. I only have room for two. and dont want the weight.

Im going to sell the truck and camper in 5-8 years. Im going smaller. Im getting me a colorado chevy and going back to basics with a 7.6 camper no slides.

get back to off the beaten path

[lawrosa]

prichardson wrote:
Sounds like you are worried about recharge time. Charge time is dependent on how much amperage has been removed from the battery bank. It does not matter if it is 2 12s in parallel or 2 6s in series. As far as the charger is concerned it is one big 12vdc battery.

I assume more resistance in the 6 ers and being series.

Parralel 12's powered inverter well and charged fast.. Just my perception.

My inverter kicks off at 10 volts. alrm goes off at 10.5.

[lawrosa]

BFL13 wrote:
Voltage drop at high amps also relates to the size of the bank in AH. More AH less drop. I don't have exact numbers, but the two 6s at 215AH will do way better than the two 12s at 150AH despite being 6s instead of 12s.

Go for the 6s!

Im leaning that way. at 54 years old I guess I should try them. Ive only every owned single twelves back in the day, then always dual 12's. Had a single 31 once. But mostly 2 24's.

Ive had all brands, but like the duracells best so far. 6 years was a good run for me. The first camper they were in only powered lighting and small 120 watt inverters that plug into cig lighters. For TV, lights, etc etc.

[lawrosa]

wanderingaimlessly wrote:
6V GC batteries from all that I have read are true deep cycle batteries that are not damaged by drawing down by 50%. The same can not be said for 12 volt RV/Marine batteries.
GC batteries are designed and built for the type of usage you are exposing them to.

Yes but the plates have the same specs. Glass matt type stuff. see ny foot notes in OP And the 12's ft notes show CCA get reduced 15% in the deep cycle 12's. somehow I feel the 6's are the same just more lead and that they are 6 volt.

Im thinking I may not get drastic voltage drop with the 215 ah / 6ers

[lawrosa]

MEXICOWANDERER wrote:
Sir you out do not dip all cells. Yout dip the weakest cell in the battery and only have to verify once or twice a year.

Top charge all batteries then cycle them a few times. The lowest cell will reveal itself.

I did that throughout the 6 years the 12's lived. The weak cells I thought were weak, one on each battery, was not even the cell that fried..

What I noticed was an issue with the voltage being low. Testing each cell then they all came out good but one. When drawing out with the hydrometer the acid was red/blackish. Dead!!!!

I drove those batts hard too with my inverter. Often took them down to 12 volts. A few oops below that.

electric coffee pot and toaster ovens are my friends. I can get along without them though.

[red31]

A Study on CEF lead acid ...

"More importantly, notice the
dramatically lower efficiencies for the increments above
about 80% state of charge, where most values are below
60% efficiency, and full charge is represented by less
than 50% efficiency. "

[wa8yxm]

There are many very technicial pages on the relationship between internal resistance, Capacity in amp hours and recharge but unless you have a degree in electrical/electronics engineering .....

The bottom line is the bigger the battery the more amp hours the lower the resistance.. HOWEVER for GC2 and bigger this is not the limiting factor. My Converter is 80 amps. I have seen Inverter/chargers that can hit 100.. Xantrex recommends no more than 0.30 C recharger rate (Where C is the 20 hour Amp hour capacity) so for my G-20s (230 amp horus (that's 69 amps. add in a bit more for the starting battery *(73AH so it can take around 22 amps) and the 80 is right.

I"ve added a bit more so I can eat it all

Recharge time is a function of State of discharge, converter size, actual charge rate up to around 90% SOC.. then 2-4 hours to finish.

[BFL13]

pnichols wrote:

BFL13 wrote:

prichardson wrote:
Sounds like you are worried about recharge time. Charge time is dependent on how much amperage has been removed from the battery bank. It does not matter if it is 2 12s in parallel or 2 6s in series. As far as the charger is concerned it is one big 12vdc battery.

You do faster time if you remove more! 🙂 By doing 50-80s instead of 70-100s (both 30AH)

But then your bank is lower in AH (higher R) while camping so voltage drop is more. Try to still have enough AH at 50% to run the inverter loads and do 50-80s for fast charging too.

That can mean four 6s instead of just two. And a bigger amp charger and gen to run it to still keep the time down. And a bigger Rv to carry the four batteries. And a bigger truck to pull it.

Interesting concerning your comments above on battery "R" (internal resistance?)!

Can you provide a technical link talking about lead acid battery (6V or 12V) internal resistance changing much at all based on how far down they are discharged?

I've always thought that internal lead acid battery intrinsic internal resistance depended entirely upon such factors as physics, chemistry, and construction - but I could be wrong.

I am going with how you can run the big things on the 2000w inverter down to 75% SOC on two 6s before the inverter hits the 11v alarm with voltage drop, compared with how you can run the same load at 50% SOC if you have four 6s.

Four 6s have less R (What I call it 🙂 ) than two. So I ASSume the two at 75% have the same R as four at 50%, which means the two have more R below 75%

OTOH--I remember from Salvo days that R of a wire stays the same and it is the amps variable that affects voltage drop.

You are invited to explain all this! 🙂