Amp Hour question

Don't "dish" 100W of solar! Those of us with smaller rigs likely have less power consumption than the "big guys". My 100W portable keeps me going for 5 to 6 days (usually moving again at that point...), since I, too, only have a single house battery. Sometimes "older is better" - NO 12V drain for my refer when on propane. And my CO meter is 9V battery powered. Only LP alarm off house battery. 4aSong - you should do real well with that set-up in AZ - works for me in the shady/cloudy northeast! ST

75 would be its reported 1 amp discharge rating as seen with their other marine batteries, not 20 hr

red31 wrote:
Based on the 24 DP's RC of 100 and the 'regular' 24's RC of 140 I'm guessing the 24 DP comes in @ 56ah each.

Had good luck with general inquiries of the battery maker Johnson Controls

johnson controls general inquires

Based on the battery specifications given by Interstate and others it is, as I said 73.

All the figures I gave were researched,They are NOT estimates but actual numbers obtained from East Penn, Johnson Controls and US-battery.

Here ya go 69 ah based on this '04 spread sheet from JCI

BCI average amp hour capacity for a group 24 is 85. You learn from the amp hour meter readings what your batteries actual rating is.

Based on the 24 DP's RC of 100 and the 'regular' 24's RC of 140 I'm guessing the 24 DP comes in @ 56ah each.

Had good luck with general inquiries of the battery maker Johnson Controls

johnson controls general inquires

4aSong wrote:
When setting proper battery size and type the controller has a rated value field for the Amp Hours which I cannot locate on either of my 12 volt Interstate group 24 (HD-24-DP) batteries

75 amp hours each 150 total (Well 73 and 146)

Group 24 about 75 (73)
Group 27 Just below 100 (95)
Group 29 Just above 100(105)
Group 31 About 130
Size 4D 230
Pair of GC-2 Wired in series to make one BIG 12 volt..210-230 (See 4D)

You can use the Round number but there is a slight difference between one brand and another (As you can see the difference is very small).

In addition: GC-2 (And you can get a 4D this way) are DEEP CYCLE
Most of the batteries identified as GROUP XX above are MARINE/deep cycle starting batteries.. What is the difference?

A MARIN/deep cycle should be kept around 3/4 full at the minimum, that is out of every 100 amp hours of capacity only 25, perhaps 30 are usable before serious long term damage sets in

A true DEEP CYCLE like the GC2 you can to to half full without doing serious damage.

Next we get Floooded Wet Cell,,, Maintenace free, AGM

The flooded wet you can add DISTILLED water as needed to replenish that which is "Boiled" off (Itis not really boiling it is electrolysis)

The others you can not SOME (myself included) think this is an advantage for Flooded wet.

AGM may well have a lower INTERNAL resistance They can also be mountd without regard to "THIS SIDE UP" You can find small (GROUP ##) AGM in DEEP CYCLE types.. THEY ARE EXPENSIVE.

GC-2 is best bang for your buck (Baring one heck of a sale on AGM)

100 watts of solar is close to the edge of what will keep the battery charged over long periods camping.

BUT: it can certainly make enough if you can find a sunny spot. Total of 100 AH battery does not give a lot breathing room, but in good weather is probably enough.

I keep hearing the mantra of never go below 50%, that's a great idea in theory; but in the real world going to 20% or so sometimes is certainly not a killer. Just make sure the battery is brought up to 100% as soon as you can.

Doug

My guess would be the 45 comes from estimating 90 amp hours for a good deep cycle battery but realizing you shouldn't discharge below 50% of that. You want your family to see zero energy remaining on the meter at that point and turn off the TV.

Really 100 watts is nothing in a RV. Sure it will attempt to charge the battery, but your CO meter, propane detector and refrigerator will combined use about 35 amp hours daily

If so, we wouldn't have been able to go four days on 2 batteries (50% discharge) without charging! Our fridge must use less power than that. Or it may be cooler where we camp. No light, no defrost feature, no fan. CO detector runs on a 9 volt battery. I made a few measurements and figure a 100 watt solar panel should let us go without other charging sources for twice as long - a full week. Of course we don't carry a TV and use propane to make coffee.

Thanks to everyone for your inputs on the AH rating for my batteries.
Just to be sure I have contacted Interstate today and explained to them that I needed the Amp Hour rating on their HD-24-DP and still waiting for a response. In the interim I have set the controller to 100AH.
Will update this posting once I receive back from Interstate.