Yamaha Drive new batteries pulling down too quickly

rainesbros

I have a 2010 Yamaha Drive YDRE. Purchased new in 2010. In 2015 I replaced batteries with same as stock, four 12v Trojan T1275. For 1 year everything was fine with the batteries pulling down from full charge to about 20% of based on the stock battery meter after 6-7 hrs of use. Then suddenly the batteries would drain from full down to about 20% after less than 1 hour of use and the cart had significantly diminished torque when driving uphill. I disconnected the batteries to reset the stock charge indicator, and drove it through several cycles of charging and driving, and tested the battery voltage at full and at increments during discharge - the voltage readings appeared to be consistent with the reading from the charge indicator, meter says 100% full when voltage reads 51v and 20% full when voltage is 48v. I took the cart and Yamaha charger to our local authorized Yamaha dealer and they said batteries needed to be replaced, so we replaced them again. The cart still suffered from the same condition, pulling down from full charge to about 20% after less than 1 hour of use and has very low torque struggling to drive uphill. So back to the dealer and they installed six new 8 volt Trojan batteries, and same problem with charge pulling down from 100% to 20% after about 1 hour of use and very low torque going uphill. Any suggestions what could be the problem or what I can test?

BGW

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pandmautocare

You have some type of restriction....either the motor has issues or your brake is dragging....have you jacked it up to see if the wheels spin freely?.... Brake adjusted properly?

rainesbros

Thanks for the suggestion. I jacked up the front and rear ends and confirmed that all 4 wheels turn without restriction. I wish that was the problem because it would fit the symptoms and lead to a relatively straightforward fix.

Molon Labe USA

48 volts on a 48V pack is ~50% discharged, not 20%. I don't know what the problem could be. 1 hour of going up decent hills, or constantly using partial throttle will wear batteries down relatively quick, as in an hour.

yamahaguy97

Yeah decent hills will take their toll on battery power, but going from 100 percent charge to 20 in an hour, you must really be working that thing lol. On level ground and maybe some uneven ground you should get 6-8 hours from good batteries. And not that it will make a huge difference per say, but after you drive and it really boggs down, feel all the battery cables and the cables going to the solenoid and motor and even the controller. See if any get particularly hot and you may find points of resistance. At this point look for anything that could potentially effect the cart. Also when you charge the car back up you can also feel the cables to see if any get really hot

rainesbros

Appreciate the comments and suggestions. It pulls down to 47.5v after 1 hour of driving on flat surface. Before this problem it used to pull down to the 47.5v range after about 6 hours of driving on flat surface. I have a small hill, 40' rise over about 200' of run where it used to power up with no problem with 4 people on board but now it struggles to with only 1 person on board and won't make it up at all with 2 people on board. I will check for hot spots next.

Molon Labe USA

Maybe cable or cable connection issues/deterioration?

rainesbros

I put on new cables with the new batteries last year. All connections are tight.

Molon Labe USA

What's the pack voltage on the new pack when it's 100% charged?

bird6246

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