Battery Maintainer - Charger ?

[Ironhorse]

Winter is coming this way, again, and with it comes the problem of trying to keep the batteries up on all the vehicles in the shop. Hence, the question here:

Seems as if my battery maintainers are all dying off one by one. Have 4 total, 1 each for the '71 4x4, '71 Chevelle, '86 Monte Carlo LS and the ZTR mower. Have tried what I thought were good maintenance trickle chargers, 6/12 volt capable. Have had Schumachers and Sears Brand Die Hard chargers. All did well for couple years and then slowly but surely died off one by one. With my '57 2 dr. coming home from paint at some point I will need to add a 5th charger. Thinking I need more of a "float" type charger rather than a "trickle" charger. Difference in a float charger battery charges til full and then turns off until battery charge drops to a certain point then begins charging again. The trickle charger constantly charges constantly.

Have looked at a Black and Decker BM3B 6/12 volt capable, seems to have good reviews and won't break the bank needing 5 chargers total. Anyone have experience with the B&D BM3B float battery charger or a similar type/brand?