It used to be, if a battery does not list CCA ratings it is a Deep cycle battery.
BUT, that is no longer true.
One must know that Interstate is a battery marketer, they are not a manufacturer. Currently Most of their engine starting batteries are made by Johnson Controls. Who make what for whom is constantly changing. In my opinion Interstate batteries do not deserve their reputation, but there is marketing for you.
A 100 amp hour battery when measured at the 20 hour rate, can provide 5 amps for 20 hours before battery voltage drops to 10.5 volts, which is considered 100% discharged.
But, one can indeed discharge a battery below 10.5 volts, and this is like throwing a brick to a drowning person.
Marine batteries have both Automotive posts, and threaded studs to attach ring terminals.
if a battery only has Automotive posts, 99% chance it is only a starting battery and is not fit for deep cycle or dual purpose duties.
Pass on this battery. Johnson controls makes most of Wally worlds batteries. While JC could certainly make batteries for interstate to a higher quality level than interstate, many argue that doing so would cost them more in the long run and that they are exactly the same internally.
Only someone inside the particular battery manufacturer center, wherever it might be located, knows for sure.
The most poorly manufactured battery kept fully charged its whole life, will outlast the best battery chronically undercharged, so peoples experiences with how long a battery lasts has very little revelance to the battery coming off the line and relabeled today.
If you are really eager to spend as little as possible on a battery, get a marine battery from Wally world and do your best to return it to full charge whenever possible. And when it fails, perhaps still under warranty, then wally worlds are everywhere and most employees in the auto department don't worry too much about wally worlds bottom line and just replace it.
But some do.
Battery group sizes like 48, 27, 41 76 ect are not directly proportional to their capacity either.
The more common sizes of marine batteries, which are more desirable just becuase they move faster and are likely fresher, are group 24, 27 and 31.
Wally world has made up a new group size(29) which is either a group 27 or group 31 depending on the last time the locusts ran. These range from 100 to 120 AH capacity, but wally world also likes to use different rates than the standard 20 hour rate to make their batteries appear to magically have more capacity than their competitor's at Autoparts stores.
If you see two batteries the same size in wally world, and want to know which one is the better battery for van dwelling, go get a bathroom scale and see which one is heavier. Heavier is better.
Also if the rack of batteries has several of the same size, the battery in the back is likely the newest one, and that is the one you want, not the one which has been sitting on the shelf for 3 months.
Batteries self discharge just sitting, and when they fall below 80% charged, which can happen in 6 weeks, then they start losing capacity.
Beware of battery sales, these batteries are old and capacity compromised and will also fail earlier Even if they warranty them for the same amount of time from the date of purchase, the battery will not have its new capacity and it will be more resistant to returning to its maximum remaining capacity, which was compromised before you bought it.
