[Eric64]

My son has a hydraulic pump setup in his vehicle that we're playing with, It has a 36 volt battery plant. I built up a trickle charger that has an output current of 2 amps x 38 vt. My question is how do you know when they are fully charged?. I remember in the old hygrometer days but these are gel cells so I was wondering how you can tell. I thought I'd just leave it on for a day but I'd like to know if anyone out there had some info. or suggestions. Thanks, Eric

[pepi]

roughly figure 2 amps an hour and multiply 2 by the total battery amperage.. should get you close

[Eric64]

Thanks so much, I had no idea where to start.

[cobalt327]

Originally Posted by Eric64

My son has a hydraulic pump setup in his vehicle that we're playing with, It has a 36 volt battery plant. I built up a trickle charger that has an output current of 2 amps x 38 vt. My question is how do you know when they are fully charged?

You need to use a voltage meter to see what the voltage is, and/or a load test. You have to know where you are at, charge-wise- to know how much additional charge is required to bring them to fully charged.

More info HERE.

Check out the table, Temperature Compensated Battery State-of-Charge (SoC) Table located HERE, for voltage measurements related to battery charge condition.

In any event, do not allow the battery(s) to become hot to the touch while charging, and do be sure of the type of battery you're working with- sometimes a maintenance-free battery will be mistakenly called a "gel cell". Gel cell and Absorbed Glass Mat (AGM) batteries have different requirements than traditional wet-cell batteries.

[ChevelleSS_LS6]

Battery tender... set it and forget it. My motorcycle's been that way since last year.