NAPA Commercial 12v Battery ( Amp Hour? )

[JimInMich]

My MH came with two of the NAPA Commercial 12v batteries (part#7236) as my coach bank. I read people chatting about having 220amphour, ect. I don't see that rating on this battery. Is there a formula to find out?
From the NAPA web site:

Battery Application Commercial
Battery BCI # BCI # 31S
Battery Cold Cranking Amps @ 0 Degrees F 950
Battery Cranking Amps @ 32 Degrees F 1,190
Battery Load Test Amps 475

[BFL13]

Our used TC came with a NAPA battery like that. Called "HD Commercial" and I could not find any AH for it, but it weighs 56lbs as a 31 so I figured not much. I did find a similar NAPA battery somewhere Googling around that was about 1,000 CCA and had about 80AH.

IMO, if you will be on shore power mostly, they will be ok, but if you plan some off-grid 50-90s, swap them out for proper deep cycle batteries for the house bank.

[time2roll]

I would guess 220 combined is about right. Maybe a little more.
Do you need more power? What are you charging with?
Many house batteries are chronically undercharged and lose capacity.

[wa8yxm]

130 amp hours each is my guesss. the key spec was the #31

A group 31 battery is about 130 amp hours.

HOWEVER: From the ratings I'm guessing a Marine Deep cycle

Thus two are 160 AMp hours but you can't use all that, IN fact you can't even use 130 of it, only about 100 amp hours are usable after that damage sets in on the batteries.. So the GC-2, where you can safely use HALF the battery, (It is a DEEP CYCLE not a MARINE/deep cycle) is a better choice.. Or better yet, upgrade to 2 pair of GC-2

Each pair wired in series to get 12 volt, is treated exactly as a SINGLE 12 volt battery.

[Ed_Gee]

An AH rating may be available, somewhere, but this is really a heavy duty starter battery ... not a deep cycle battery designed for RV use. Consequently amp-hour specs are usually not provided. It is designed for short high current draw for starting engines, not for long moderate current draw over many hours. The physical design of the plates are quite different .... a proper deep discharge battery has much heavier plates. The GC2 type battery, in pairs of 6V types, is pretty much the standard for motorhome use - and these are also costlier .... but they tend to have longer life spans and provide more amp hours per discharge cycle than starter batteries ... or even the mid-way Marine Deep Cycle types.