I bought a new trolling motor battery today, an Optima bluetop, and see that the charger needs to be 13.8 or less voltage output. I use an old Marek Maintainer which is a trickle charger. The instructions were lost in a move long ago and this charger predates these dry cell batteries, thus my caution. The only info I can find is on the charger face, which says "115v AC, 12v DC". Does anyone have any knowledge of this charger, or these batteries, and whether I am safe using this charger?

I don't know that particular charger but if it indeed is a trickle charger it is designed to keep a battery charged but not to charge it. Look at the output again and if the amperage is around 1 amp then you need to get a charger.

An optima can charge with as much as 15.6 volts if it is regulated but normally 13.8 to 15.0 volts at no more than 10 amps. If at a high charge rate the temperature cannot go over 125 degrees.

Trickle charging should be no higher than 13.8 and 1 amp or less.

This is from the optima website.

David,

Sounds like you got better info off the website. Thanks for your input.

I have several chargers, including an onboard Guest Charge Pro, but I prefer the trickle charger because it seems to keep my batteries longer. I do use the onboard if I have to fish two days running, otherwise I plug in the Marek. But either charger will work according to your information.