Batteries

[mclainfarm]

I have 4 6 volt Duracell batteries and trying to figure out the amp hour rating. The specs are
20 amp hour rate 215
5 amp hour rate 157
6 amp hour rate 156
Minutes at 25 amps 395
Minutes at 75 amps 105
Most batteries I read about state they are 100 amp hour batteries. What are mine? I’m trying to put together a solar system and need to know the size of my battery bank. Thanks for any help

[wa8yxm]

One warning of going too low in a motor home (not so much with a trailer) is you might need to "Jump start" the generator... Just so you know.

And one advantage of the GC-2 DEEP CYCLE is a single "OH C##P" level discharge or even 2 or 3 spaced out over time won't kill 'em right away.

Where as the MARINE/deep cycle (Really starting batteries) Are less likely to recover and standard starting batteries... Toast the 1st time

[wolfe10]

time2roll wrote:
Yes for the OP 430 is the number to use for your operating estimates.

With a total battery bank of 430 AH @ 12 VDC discharging to 50% gives you 215 AH @ 12 VDC as the normally accepted usable figure for long battery life.

Sure, you can discharge deeper/use more AH, but will certainly shorten battery life. A cold night and you need the heater-- go for it.

[time2roll]

2oldman wrote:

wa8yxm wrote:
10 amps it will last a bit over 21 hours but if you draw 20 amps. no they won't make it to 10.

And we all know those rating are figuring a draw down to what.. something unusable that nobody should ever do?

450ah is essentially 225, in the real world.

50% is great when life is routine. However I would not hesitate to go lower if needed to keep the heat or some other system running in less favorable conditions.

Yes for the OP 430 is the number to use for your operating estimates.

[mchero]

I believe Mex is using this panel;


JUST KIDDING MEX

We need Mex's LAT/LON so we can see his panels via Google Earth!

[Boon_Docker]

MEXICOWANDERER wrote:
Example

My battery bank consists of 2 volt cells 12 in series for 24 volts. But at 1625 amp hours. The amp hour rating of each battery.

But this string is paralleled with an identical 2nd string
For 3200 amp hours at 24 volts.

Wow, that is quite the battery bank. How many watts of solar do you have?

[MEXICOWANDERER]

Example

My battery bank consists of 2 volt cells 12 in series for 24 volts. But at 1625 amp hours. The amp hour rating of each battery.

But this string is paralleled with an identical 2nd string
For 3200 amp hours at 24 volts.

[wolfe10]

wolfe10 wrote:
The 20 hour rate is the most common rating.

So, each of your batteries is 225 AH @ 6 VDC. So each pair wired in SERIES is 225 AH @ 12 VDC.

Both pairs together (your battery bank) is 550 AH @ 12 VDC.

Yes, sorry for the bad math-- know RV's, math-- not so much.

CORRECTED:

So, each of your batteries is 215 AH @ 6 VDC. So each pair wired in SERIES is 215 AH @ 12 VDC.

Both pairs together (your battery bank) is 430 AH @ 12 VDC.

[Boon_Docker]

mclainfarm wrote:
I have 4 6 volt Duracell batteries and trying to figure out the amp hour rating. The specs are
20 amp hour rate 215
5 amp hour rate 157
6 amp hour rate 156
Minutes at 25 amps 395
Minutes at 75 amps 105
Most batteries I read about state they are 100 amp hour batteries. What are mine? I’m trying to put together a solar system and need to know the size of my battery bank. Thanks for any help

If we put all the confusion aside you have a 430 AH battery bank with your four 6V batteries.

[2oldman]

wa8yxm wrote:
10 amps it will last a bit over 21 hours but if you draw 20 amps. no they won't make it to 10.

And we all know those rating are figuring a draw down to what.. something unusable that nobody should ever do?

450ah is essentially 225, in the real world.

[wa8yxm]

mclainfarm wrote:
I have 4 6 volt Duracell batteries and trying to figure out the amp hour rating. The specs are
20 amp hour rate 215

That is the figure we use (more on that later)
you ahve 430 amp hours at 20 hour rate and 215 usable amp hours.
(That was easy)

Now if you draw at what is that. 10 amps it will last a bit over 21 hours but if you draw 20 amps. no they won't make it to 10.

IF you want to learn why I will provide a link or two

The first link

The Second link

[MrWizard]

"20 amp hour rate 215
5 amp hour rate 157
6 amp hour rate 156"

It's the 20 Hour rating is 215 amp hrs
Means it can supply 10 amps for 20hrs 45 mins
To reach 10.5v

The 5 hrs rate is 157 amp hrs
That is discharging at a rate roughly 30 amps load
3x the load for 1/4 the time period and less total capacity

[Boon_Docker]

2oldman wrote:

wolfe10 wrote:
Both pairs together (your battery bank) is 550 AH @ 12 VDC.

-100

Some incorrect math in this thread.
-120
For a total of 430 AH @ 12VDC :B

[2oldman]

wolfe10 wrote:
Both pairs together (your battery bank) is 550 AH @ 12 VDC.

-100

[MEXICOWANDERER]

Duracell 225?

Try 208

Trojan T-105 are 220