Hello 

I am in the planning stage of rewiring the boat and have decided to move from lead acid batteries to AGM.  On reading around the subject I understand that they should be charged at between 14.6 and 14.8 volts. The place I use for my alternators are not experienced in AGM batteries and the battery supplier just sells them.
Does anybody have any practical experience of charging AGMs with an alternator?  If so what voltage are you using.

Thanks

Sandy

Hello Both 

I think we are all agreed that it is a complicated subject and perhaps my automobile analogy was not the best - I was trying to show that the modern AGM is used for many thousands of hours while being charged at 14.x volts.  My power requirements are pretty minimal, charging from an alternator is not my primary source, as I've said before, the Watt and Sea whilst underway and I expect a small solar panel whilst at anchor (which can be added to the W&S controller). 

It dawned on me that I could rig up the alternator so that it could be disconnected from the drive belt if I needed to motor any great distance.

Spent an hour this afternoon speaking to a chap who sailed across the Atlantic in a boat with a temperamental engine and a 100 Ah battery and lived to tell the tail. 

Regards

Sandy