2008 EZGO RXV 48V Performance Issues.

[Hschloss62]

Good Morning,

I have a 2008 EZGO RXV, and I have been having some performance issues this year that I am a little stuck on.

Some background, I purchased the cart about 4 years ago from a construction rental company for $500. Last year was the first year that I used it for actual golf (previously has been used lightly for yardwork, ect.) and over the winter i put a 3" lift kit on it and 20.5" wheels. The batteries were starting to fail, so I replaced all the batteries about a month ago with Crown 150AH batteries.

After replacing the batteries, I am still struggling to get a full 18 holes in. By struggling, I mean that I can get 18 holes in, but after that it struggles significantly to climb hills or make it back to my house.

I have fully charged the batteries, let it sit for about 6 hours, and tested the batteries and they all show a 12.7 or 12.6 volt reading, which leads me to believe the batteries aren't duds.

After a full charge, when I press the accelerator the volt reading drops down to about 42-43v and then gradually comes back up to about 48-50 when the cart gets up to speed and roughly 50v when sitting. Is the drop to 42-43v normal upon acceleration? When climbing hills (admittedly some or rather steep) it drops down to about 40v. Towards the end of the round, the volts will drop down to around 38-39v upon pressing the accelerator, eventually getting back up to 45-47v upon reaching speed and 49v when sitting.

I am wondering if - because I am relatively confident the batteries aren't bad- this would mean the motor is either under powered or starting to fail, resulting in it drawing excessive amps and therefore causing them to drain faster than normal? Or would this be a controller issue?

Any helpful suggestions would be appreciated.

Thank you

[ojo]

Looks like a problem with the batteries, not with the motor. The voltages you mentioned seems too low. After fully charged and rest for some hours, they should have at least 12.8/12.9v. What type of batteries is it?

[Hschloss62]

I have 4 Crown 12v 150 AH Batteries that I bought about a month ago.

[Reddawg454]

Its possible to get a bad new battery. You need to check the voltage under load of each battery to see if one drops more than the others.

[kernal]

Assume the batteries are new, you have receipt/warranty and they weren't sitting on the shelf somewhere for months before you bought them.

Possibilities: bad wheel bearings/drag. assume you would have noticed this when installing new wheels but ya never know. 2008 is the first year for the RXV and there are known issues with the parking brake (aka motor brake). If it has a handle on it, its original. might be some drag there if not releasing all the way due to corrosion etc. If dragging much you should smell it but a little drag combined with other issues might exacerbate the situation. This could also be a problem with a new style brake. Batteries: new batteries do not provide advertised capacity until "broken in" (aka formatted). Trojan says this could take as much as 100 charge cycles but some improvement should be evident after 20-30. Crown should be similar. You say resting voltage is 12.6/12.7. If I assume 2 at 12.6 and 2 at 12.7 that is 50.6 total which is low. Fully charged pack should be 50.9 and often new packs rest at 51.1. Doesn't sound like much but 50.6 is only about 96% charged. Charger should take the pack to ~65v before auto shutoff. You didn't say where you are but weather(temp) has a large effect on battery capacity. Batteries at 60° loose 15-20% capacity compared to 80°. They have a large thermal mass so the temp the night before use is the temp you should use for comparison. You didn't say how far you have to drive to the course either. Could be a combination of things adding up to insufficient range for your situation and might get better as batteries break in and temp warms up. One last thing on batteries. 12v batteries have the lowest capacity compared to 8v and 6v. The Crown 150 are on the low side of the 12v range. So you are starting out with a smaller gas tank than many. I have 170ah 8v batteries in my RXV. Again, doesn't sound like much but it is a significantly larger tank.

Having said all that, unless you are driving 10 miles one way to the course or something, those batteries should be sufficient if conditions are optimal.

[Hschloss62]

Originally Posted by kernal

Assume the batteries are new, you have receipt/warranty and they weren't sitting on the shelf somewhere for months before you bought them.

Possibilities: bad wheel bearings/drag. assume you would have noticed this when installing new wheels but ya never know. 2008 is the first year for the RXV and there are known issues with the parking brake (aka motor brake). If it has a handle on it, its original. might be some drag there if not releasing all the way due to corrosion etc. If dragging much you should smell it but a little drag combined with other issues might exacerbate the situation. This could also be a problem with a new style brake. Batteries: new batteries do not provide advertised capacity until "broken in" (aka formatted). Trojan says this could take as much as 100 charge cycles but some improvement should be evident after 20-30. Crown should be similar. You say resting voltage is 12.6/12.7. If I assume 2 at 12.6 and 2 at 12.7 that is 50.6 total which is low. Fully charged pack should be 50.9 and often new packs rest at 51.1. Doesn't sound like much but 50.6 is only about 96% charged. Charger should take the pack to ~65v before auto shutoff. You didn't say where you are but weather(temp) has a large effect on battery capacity. Batteries at 60° loose 15-20% capacity compared to 80°. They have a large thermal mass so the temp the night before use is the temp you should use for comparison. You didn't say how far you have to drive to the course either. Could be a combination of things adding up to insufficient range for your situation and might get better as batteries break in and temp warms up. One last thing on batteries. 12v batteries have the lowest capacity compared to 8v and 6v. The Crown 150 are on the low side of the 12v range. So you are starting out with a smaller gas tank than many. I have 170ah 8v batteries in my RXV. Again, doesn't sound like much but it is a significantly larger tank.

Kernal,

Thank you for the advice. I live in Northern Kentucky, so although it has been getting relatively warm here during the day, it has still been dipping into the 40's at night. I live on a golf course so my travel to and from the course consists of driving through my back yard.

I keep my cart on the charger overnight, so I didn't think the overnight temp would effect the batteries that much. But maybe I was wrong to think that the charger would keep the batteries from getting cold. Maybe (hopefully) my only issue is me being too anxious for spring golf and trying to use the golf cart on cold batteries.

Aside from that, I will start familiarizing myself with how to evaluate the motor brake.

Thank you

[kernal]

charger won't keep batteries warm. as batteries approach end of life they will heat up significantly while charging due to high internal resistance but this is not the case when new.

[Hschloss62]

Alright so before I enter full panic mode thinking I bought bad batteries I should probably just wait until it starts to warm up?

[kernal]

If it were me, I wouldn't panic yet. there is a date code on the batteries. probably engraved on the case. all 4 should be the same. if you suspect the batteries might be old stock we could help you decode and if necessary you could go back to the seller. unlikely but we've seen it happen.
Keep monitoring the voltage. looking for the resting voltage to increase as charge cycles increase in number. charge after every use. Check water. don't assume new batteries have the correct water level. pray for warmer weather. check tire pressure. low pressure affects electric carts negatively, both in speed and range. Also, look at the brake. the auto brake is great when working correctly but there are issues especially with the older carts. They should be either completely engaged or off. there have been issues with them partially engaged because of corrosion or some other failure. the 08 and 09 models were notorious for this and solenoid issues also. If your brake has the handle on it, it needs to be replaced with the modern one as a matter of course and the solenoid also because if they haven't failed by some miracle they will.

[Hschloss62]

Just wanted to provide a little update.

I drove my golf cart around yesterday evening (played 15 holes). When I took the cart off the charger before going out the battery meter read 51.12v. When I pressed on the accelerator is dropped down to roughly 42-43v and then slowly came back up to around 49v when at top speed on somewhat flat ground. Is this magnitude of volt drop when accelerating normal?


After finishing golfing, I let the cart sit for about an hour or so and tested each individual battery:

12.52v
12.50v
12.50v
12.50v

(the SoC meter on my cart was showing 49.92 for some reason. Don't know why it was different than when I tested with a multimeter)

I am going to see how to slow play this and see if the batteries get better as it warms up, just wanted to throw this out there.