36v loses power and top speed

[cale918]

I have an 89 DS that is a 36v. I bought it in March and the previous owner replaced the batteries with Duracell's in December on 2015, so theyre just over a year old. they original owner had a cheap little 5amp charger for a few months. I used it for about a month and bought a 18(ish) amp DPI charger. It ran great for a few months, top speed about 12-14 then about September it started fading, losing speed, getting REEAALLY slow on hills etc with top speed at 8-9mph now. I checked the water and put about 1 gallon in between all 6. It hasn't seemed to help it much since.

I sent the cart to the shop about a month ago to have the brakes fixed. While it was there they cleaned the connections etc and tested the batteries after I explained to them what was happening. They said the batteries tested fine. (which is kind of hard not to believe given they could sell me new ones).
They were out of ideas as to why it is running slow. To me it seems that this issue is a characteristic of weak batteries.

My question is between the sweeper, coils, motor etc is there something else to blame? Id hate to buy a new set of Trojans and have the same issue still or it work greta again then have the same issue in 6mo-1yr. A friend of mine has a 36v ezgo and replaced his batteries with Trojans 1 year ago and he is facing the same issue I am. He has a lift and large tires.

The cart gets driven a half mile up to two miles on the high end pretty much each weekend around our weekend retreat at the lake. Stored under cover and placed on the charger each Sunday until the following Friday. The charger is supposed to maintain the batteries but I have since learned the charger is smarter than the golf cart given the cart doesn't have a way to tell the charger to come back on by whatever computer the cart didn't come with in 1989.

Any help is appreciated, Thank you

[Golf cart guy]

That brand of battery is not the best. Follow that with a charger in the beginning that wasn't fully charging the batteries for however long. Follow that with a shop that may or may not have tested the batteries correctly.
I agree, they symptoms seems to point towards batteries. Short of doing the testing yourself, your at a rock and a hard place.

[Roxyflash]

I would jack the rear end off ground see if your getting all the speeds from the v glide other then that you could put a volt meter on the battery pack take it to a long hill see if voltage drops.You should charge it every nite after use.Could have a bad jump cable you can feal them after a hard drive see if any are getting real hot.

[Triscadek]

What ends (posts) do I connect to for the voltometer? Also, how do I tell if it's hitting all speeds in the air? How many should there be?

[Roxyflash]

On the pack voltage there in series so follow the jumper cables there will be two batteries that will have only one jumper cable one will be negative the other will be positive.There should be 5 speeds.Voltage depends of state of charge while running it in the jacked up position you should see 36 volts.if the cart drops voltage while testing try and measure each battery to isolate it

[cale918]

Originally Posted by Roxyflash

On the pack voltage there in series so follow the jumper cables there will be two batteries that will have only one jumper cable one will be negative the other will be positive.There should be 5 speeds.Voltage depends of state of charge while running it in the jacked up position you should see 36 volts.if the cart drops voltage while testing try and measure each battery to isolate it

Okay, I took the batteries out and took them to batteries plus where they individually tested them... THEY said they were okay however I saw they gauge dip a bit and not sure they put equal or full load on each battery.

So if I hit all 5 speeds then likely I am looking at batteries? What if the load doesn't change much at all while pulling a hit on the voltmeter? Whats normal fluctuation from a full charge?

[Sergio]

If the shop did a "starter/crank" test on the batteries, that was the wrong test for Deep Cycle.

They should have put the batteries on a "discharge machine" with a 56 amp load for 8v batteries or 75 amps for 6v batteries.

You then measure how long it takes for the batteries to reach 1.75v per cell, which should take around 1 hour, but it depends on the actual battery.

The label on your 6v batteries should tell you rated run time in minutes @75amps, You can then easily calculate how well your batteries performed against specifications.

If the voltage is not dropping much, You likely still have a coil resistor in the circuit at WOT (Wide Open Throttle).

Just drive around for a while a WOT (not partial throttle), then stop and check for heat in the coils, if they are HOT, You have an issue with the Vglide adjustment not allowing it to reach the last pad.

[cale918]

When they tested they did each battery at like 20 -30 amps for like 15-30 seconds.

Ill check the voltometer and speeds I guess. Any other info in appreciated

[Roxyflash]

To do a 15 second load test you need to load the battery at 400 amps older batteries wont pull that many amps 350 is still good 300 its weak any less i would get new ones.They should still hold 6 volts loading them this way