I have been trying to get information from ACDelco regarding their
recommended charging voltages for their Voyager M30HMF batteries. I have
a home designed/built multi-stage charger that I can tweak to be totally
optimal for any battery. I though rather than use the standard values
(or range of values) talked about for sealed lead acid batteries I would
do some tweaking.

The only answer I got back to a detailed question about
bulk/absorbtion/float currrents/voltages and the considerations I should
program in for battery temperature was "13.8 volts for charging/float".
This was after an initial attempt to fob me off with "that information
is confidential".

I should point out that these where not my choice of battery in the and
based purely on their responses to my questions I would certainly not
consider buying them again. I guess if you want good batteries, don't
buy them from a car manufactures (ACDelco is General Motors).

Does anyone have any real info for these batteries? Are other
manufacturers more forthcoming with information?

Thanks