but are they Georgia peanuts Mark
...find you a battery back up company that services computer back up systems for the data centers and most high rise office buildings have them ..... if you are looking for cheap AGM's they have a lot of take outs and some are only two years old when replaced ....and they will usually sell them for scrap prices .......but there are drawbacks to that .....
one being you will not have a 20 hr rating to go by ...the best advice i can give you is get the largest you can fit in the boat and also the heaviest ones you can find ...but you can get close on what they are rated at by comparing weigh and dimensions to other batteries its not rocket science but it will get you in the parking lot ...and the chargers and alternators don't care..... they will charge what ever you have just use the lower side of you agm settings now if you are one of these that has to know down to the last amp then stick with the ones that are in the market place with all the specs furnished so you can satisfy you math..... but for me $100.00 dollars every 3 or 4 years is a good deal.....i have 3 ...80 pounders (about 320 amps) in my house bank and one 50 pounder (about 70 amps) as my back up ....all the bubba fishermen have them for there trolling motors as they last a lot longer on a 12 hr day fishing than the off the shelf trolling batteries ....i call my bank bubba just for that reason ...i also call my 2gm20f yanmar "loose change" because i bought it with my collected change that was on my dresser ...there is a way to tell the amp hr rating for these buy i have no idea what the formula is the guy i help from time to time can not cross over from his knowledge mathematically to tell me how they stack up with the market ratings ....don't misunderstand that ...he is just technically inclined that he has never sat down and educated his self on the simple side of relating these to laymen terms....oh and i may eat my advice some day but for now i am giving it a go
