This summer I replaced all of my batteries as I normally do every two years but this year decided to bite the bullet and go the AGM route. I have two of the Duracell 31M series on my trolling motor and one for my starting battery. Someone recently told me that I shouldn't be running and AGM on my Mercury XR6 because it would melt the rectifiers and start a fire. This is the first I have heard of this and so I looked at the spec's of the Duracell 31 series AGM and a 27 series flooded wet cell starting battery and honestly i can't see a reason someone would make that claim. So I'm asking for some technical evedence that this is a substantial risk as the last thing I want to do is burn up my engine and/or my boat.

Never heard of that claim.

i'm with Pat.
i recommend the AGM for a starting battery for guys that have several of those huge electronic devices as they have
more reserve capacity to allow the engine to have power to start.

There's big stink about it on BBC. Supposedly the lower resistance of AGM's places too much demand on older Merc's with stator type charging systems but is ok with newer alternator charging systems. Not sure of the validity of it though.

Is it just the Merc's ?

No idea. Like I said, not sure of the validity of it but a bunch of threads about it on BBC

on BBC its only a problem with tha merc motors if you "don't provide tha serial number"......

Lol

Well after looking at all of the BBC conversations I think I'll just keep watch over it like checking the regulators and wiring. The regulators are OEM and about five years old (replaced because of another issue) so they should be in good shape. I did find this post on BBC and it is a very good argument why it shouldn't be a problem. I do run Lowrance Elite 9ti at the consol but when stopping to fish I always put it in standby and have a Hook 7 on the bow and also put it in standby when moving from spot to spot. Unless I'm in a tournament the livewell pumps only run when I take my family Crappie fishing and want to keep some. So as soon as I get home or to where I'm staying the charger gets plugged in until next time out (three bank charger for all of the batteries). So all in all the battery shouldn't be drawn down to the point that the charging system is having to work very hard to recharge the cranking battery.

http://www.bbcboards.net/showthread.php?t=835113&p=8633612&viewfull=1#post8633612