on board charger

 MikeW62  
Outdoorsman 

Registered: 05/12/12 
Posts: 23 
Loc: The Colony TX

Is there a way to test them to see if they are working? I have 4 new batteries but still not getting the thrust that a forTrex 112 should have. I have a pic of what the charger is showing. 3 of the 4 are red when charging and green when complete. The last one is green and loose connection all the time even though all connections are tight. That is what prompted me to change the batteries to begin with. Any ideas? Thanks

Unhook your positive lead and hook a amp meter in line. Should give you the amps its charging.

After the batteries have been on charger overnite and are still being charged (floated), check that each battery is measuring at least 13 (and as high as ~15) volts. If so the charger is applying a good charge.

Disconnect charger and with no loads, wait/set 24 hours. Each flooded lead acid battery should then read at least 12.6 volts.

If you are losing TM too early in the day, what size batteries are you using and what is their RC minutes rating? Each one at the end of the normal day should measure at least ~12.2 or more volts if you are not over-discharging.

Few people, if any, are going to have a DC amp meter capable of measuring charging current. Most meters are limited to measuring milliamps.

Lou is correct. The batteries should be charged independently for 24 hours, allowed to rest for 24 hours to eliminate the reading of a surface charge and then load tested. A voltage check will tell you if they are holding a charge, but testing it under a load will tell you if you have a bad cell or one that is going bad. Harbor Freight sells a resistive load tester for around $12 and is a good addition to your tool box.

Ok, this might sound bad but I'm just a dumb plumber. I don't know how to read volt meters or what a load is. All I know is yellow lights is charging green lights is charged. All batteries are brand new and is the same bank on the charger that shows a very dim green with a red light that says check connection. If there is somebody in the Lewisville, colony, north Dallas area i will pay you for your time to swing by and check it out. I miss fishing!

swap the onboard charger connection that is showing "check connection" with another battery.
if same condition same bank , its the charger, if different , its the battery .

Thanks heyBaylor. The check connection did follow after switching. So my question now would be is the whole charger bad or just the one bank? If it is just the bank can I unhook that bank and charge that battery with a regular battery charger?

why not ? I use the good bank on a broken two bank to keep my lawnmower charged .
btw , some of those multibank chargers have a fuse in the line (one in each line) , you may want to check?

Never too late to learn.

Electricity behaves a lot like water.....
-voltage in volts behaves like water pressure in psi,
-resistance in ohms is like pipe diameter size.
-current in amps behave like water flow in gallons per hour.

Buy a cheap volt-ohm-meter (VOM) from Harbor Freight or Sears and with a plumbing background you will be able to make use of it in no time.

Ok, so I broke down and bought a new 4 bank charger. What sequence do the batteries need to be in for a 36 volt tm?

The trolling motor battery`s will be in series. You might do a search on TFF for a diagram. 36-Volt Motors
Use three 12-volt deep-cycle marine batteries and connect in the following manner:



1. Connect the RED wire from the trolling motor power cable to the positive (+) post of battery A. Use a 40-amp circuit breaker for motors with 81 lbs. of thrust and under. Use a 50-amp breaker for motors with more than 81 lbs. of thrust.
2. Connect the BLACK wire from the trolling motor power cable to the negative (-) post of battery C.
3. Connect a jumper from the negative (-) post of battery A to the positive (+) post of battery B.
4. Connect a jumper from the negative (-) post of battery B to the positive (+) post of battery C.

Thanks for all your input. Turned out it was a bad battery. Anybody looking for a 4 bank on board charger? I got one for sale.

We are in Gainesville and can check out your entire charging system if comes to that. We have techs that are pros at electrical systems and can definitely get to the root of your problem. Feel free to contact me at 940-665-9331 Tue-Sat. We will be glad to help any way we can.