Absorbed Glass Mat 12v batteries

[adelaidem]

Is it worth banking 2x100AMP hour AGM together or leave them isolated?
Am thinking of buying the quad charging cluster battery swiches running 1X lead acid battery for the diesel , 2xAGM for house batterys ,so im thinking i only need the Duel charging cluster if i bank the 2X AGM battery together any thoughts would be much appretiated.......southace

 

[Anonymous]

[ QUOTE ]
Is it worth banking 2x100AMP hour AGM together or leave them isolated?
Am thinking of buying the quad charging cluster battery switches running 1X lead acid battery for the diesel , 2xAGM for house batterys ,so im thinking i only need the Duel charging cluster if i bank the 2X AGM battery together any thoughts would be much appretiated.......southace

[/ QUOTE ]Firstly, let's be clear - AGM batteries are lead acid but they are sealed and only have a very small amount of liquid so they are slightly smaller and lighter than an equivalent flooded lead acid. You can also use AGMs when upside down, which has appeal to some /forums/images/graemlins/smile.gif They should also me more immune to shock, vibration and flaking of the lead due to the normal movement of cells in use.

However, because they are sealed, you must not let them over-gas, so they must not be given such a vigorous charge at the end of the charging period. For this reason you need a different charger setting for AGMs and ordinary flooded starter batteries. This is an issue whether you decide to bank the two AGMs or not and applies to your main engine as well as your mains charger.

As for the question about banking, I would bank them since you have a separate starter battery but make sure that in the event of either battery failing (o/c or s/c cell) that you can quickly remove the faulty battery from the circuit while at sea. If your battery box is in an awkward position you might decide to put in a switch. Then you could use them as two banks if and when you wanted to. Usually one battery will fail and need to be replaced before the other so it is important to do this unless it doesn't matter to you if you have no house electricity for as long as it takes to change both batteries.