Yamaha Drive new batteries pulling down too quickly

[yamahaguy97]

Originally Posted by bird6246

sounds like either the controller isnt putting the proper current out or the motor is going bad

I agree, at this point something like his motor or controller has an issue. He has already bought 2 sets of new batteries in a very short time so batteries are not the issue anymore

[smallblock450sl]

5 years of life on any 12 volt deep cycle battery is about right. Have you considered you just have a bad battery, that is causing this problem? These are mass preduced and any thing can happen. Since no individual has a download machine, might consider these 2 tests. A specific gravity test with a hydrometer. Do this test at full charge and after discharge. There are limits in readings of individual cells. Then, when discharged, jack up the car, read full battery voltage and individual battery voltages and write them down for referance. Now push the pedal and see what battery voltage drop is (might be very low with no load), while pushing the accelerator pedal and lightly applying the brake pedal, check for voltage drop again, not only the battery set, but each battery. That's about the only way you can do a battery test without a download machine. Good luck with finding the problem

[rainesbros]

After charging overnight and with my Yamaha charger indicating "charged" the pack voltage is 50.6v. I have seen it as high as 51.3v or as low as 50.2v at "charged" state. Maybe this variation suggests the charger might be part of the problem? I didn't have a chance today to drive and check for high temps but that's high on my priority list.

[rainesbros]

Originally Posted by smallblock450sl

5 years of life on any 12 volt deep cycle battery is about right. Have you considered you just have a bad battery, that is causing this problem? These are mass preduced and any thing can happen. Since no individual has a download machine, might consider these 2 tests. A specific gravity test with a hydrometer. Do this test at full charge and after discharge. There are limits in readings of individual cells. Then, when discharged, jack up the car, read full battery voltage and individual battery voltages and write them down for referance. Now push the pedal and see what battery voltage drop is (might be very low with no load), while pushing the accelerator pedal and lightly applying the brake pedal, check for voltage drop again, not only the battery set, but each battery. That's about the only way you can do a battery test without a download machine. Good luck with finding the problem

Thanks for the suggestion. I'll perform the testing as prescribed.

[cre73]

Did you ever find the root cause? Having a similar issue.