What size battery is this?

[chriscraft]

I need to replace a deep cycle battery on my RIB. The current one is marked "85 Amps (12 hours)". I suspect it is not 85 Ampere Hours, but it might be? Could anyone confirm what rating this battery is likely to be in Ampere Hours. Thanks.

[doggypaddle]

I would say its almost a certainty its 85ah. I can't think what else the 85 would be?
the 12hours backs this up, its 85ah when discharged over 12 hours, or 85ah on the 12 hour rate. you can also get a 5 hour rate which would be around 60 ish for the same battery as the effeciency falls with higher discharge rates. (though you wont find this on a leisure battery as the 12 hour rate sounds better in the sales literature)
to give you some idea the 85ah leisure batteries are usually large car battery size, and the 110ah size are small lorry battery size.