EZGO RXV Charger will not shutoff and never gets to finish charge

[ezgoRXVinGA]

New here and new to golf carts as of last Spring, but I have learned quite a bit just browsing the forum, thanks for all the info so far.

2009 RXV with 4 12V Crown batteries (2 yrs old)

My problem began several months ago. First the supplied Powerwise QE charger supplied with the cart (bought used) went bad. The place that built the cart was nice enough to swap it out with another used charger. However, after this, I began noticing that that I would never get to a finish charge with the charger and it would give a fault. I checked the batteries and they seemed good to to go, and I have not noticed any degradation in drive time (but we have only gone on short trips this winter). My steps in troubleshooting:

1) Gray wire on receptacle - After some researching, I learned that the gray wire on the power receptacle may get too hot and cause charging issues, mine was not melted but looked as it could have some heat damage, so ordered that specific wire and put on a new one. Not totally convinced it is the correct part however, as the small black box is slightly smaller than the original.

2) Cleaned batteries - Cleaned all batteries (had a little corrosion on terminals), and wire connections with baking soda/water solution.

3) Ordered DPI charger - Thought the charger may not be operating correctly, ordered a DPI charger and set it to Crown battery mode. Similar result as Powerwise, but in the case of the DPI, it never comes down below about 14 Amps after charging for many hours. Took DPI charger over to my neighbors and worked as advertised. Amps dropped appropriately and was fully charged with green light in approx 3 hrs.

After multiple iterations of charging and discharging and testing the voltage and specific gravity; here is what I am left with:

1) Specific Gravity has checked good with the hydrometer several times in every cell.

2) Checked voltage using multimeter and all batteries are withing .02 volts of each other with the majority of the time being within .01 volts of each other.

3) Today, after taking readings while charging this is what I recorded (have 2 yr old Crown batteries):

Prior to Charging:
50.6 / 12.7 / 12.7 / 12.6 / 12.5

3.5 hrs into Charging (with charger plugged in):
56.9 / 14.2 / 14.2 / 14.2 / 14.2 (Charger showing 15 amps)

4.5 hrs into:
57.1 / 14.2 / 14.1 / 14.2 / 14.2 (Charger showing 14 amps)

5.5 hrs into:
56.0 14.1 / 14.0 / 14.0 / 14.0 (Charger back at 15 amps)
- I pulled the charger at this point because my water level was getting low and the voltage drop across the pack seemed to be the turning point that it will do as previous and never get to the finish charge mode.

4) Finally, in this saga of charging and trying to figure this out, I have noticed the "rotten eggs" smell and stopped charging and noticed the water level below the top of the plates in one of the batteries (this was after letting the charger go on the order of 14 hrs of charging. I have also noticed that the "fins" on the internal metal plates have gray matter in between them. Is this the sulphation and could this be the root of the problem.

Thanks ahead of time for those who made it this far reading the long description. Any help would be appreciated, as I hate to spend money on a diagnostic to find that I have to replace the batteries anyway.



What am I missing? Doing incorrectly? Or am I screwed and need new batteries?

[Golferdave]

Could be batteries
When the 1st charger went bad, it just quit charging ?
Ran down low when the charger failed?
Do you run the cart a lot?

You don't know all their history, could have many charge cycle on them before you got the cart.

Can you take them to the place you got the cart & have a load test done on them?
& try another charger for a few day?

All Good wires & good clean connections, batts are suspect.

4 - 12 volt batts don't last as long as 6 - 8 v batts.
2 years of lots of use could mean they need replaced

When yo get New batts;
you'll be taking better care of them & know their history.

[teecro]

I think that you have already answered your own question. It indeed is sounding like 1 or 2 of your batteries are slowly going bad. The DPI worked as it should on another cart but not yours. Now you're charging voltage are nowhere near too high though as you can easily see upward of 65 volts while charging a 48 volt pack without causing damage as long as the amperage starts coming down. Which it should start doing somewhere around 56 to 59 volts.

Your old charger may have been short charging which can happen as the caps inside age the voltage may drift and they slowly start putting out less and less voltage.

Be sure your water level is at least 1/4" over your plates and let the DPI run for at the very least 16 hours and as long as 24 hours to see if it can bring your batteries up further and for the amperage to reduce....

[cgtech]

Yep, let the charger run longer. The batteries never getting near 60v is a problem that is a common problem on batteries that are on their way out due to poor treatment over time by the charger (even though the run time seems adequate during the short trips tested).

[teecro]

Originally Posted by cgtech

Yep, let the charger run longer. The batteries never getting near 60v is a problem that is a common problem on batteries that are on their way out due to poor treatment over time by the charger (even though the run time seems adequate during the short trips tested).

I am a firm believer in set it and forget it... My DPI Smart-Charger gets plugged into the cart and simply is forgotten... I'm gone on 4-week hitches and I'm sure with the cold weather that my wife does not touch the cart so it sits plugged in 24/7 the entire time I'm gone. Batteries are 2.5 years old and have only needed water once...

[kgsc]

I'm with cg in let it run. Fill the batteries to just below the normal fill point, hook up the charger and let it go until it shuts off. Also if you do have to replace the batteries look into switching to 6 8s. Better run time and seem to have a better life span.

[ezgoRXVinGA]

I appreciate all the replies. I topped off the water and charger hooked up, plan to let it go until it shuts off. Crossing my fingers.

[kernal]

Firstly, how did you determine the batteries are 2 years old?

In the past I have experienced the same symptoms as you and it turned out to be batteries at end of life. You can still use them as long as they get you where you want to go but expect the deterioration to increase rapidly.

FWIW, a local independent dealer here who specializes in the RXV experienced a rash of problems with Crown 12v batteries specifically. On the other hand, I heard a similar operation in the Commerce Ga. area was having similar problems with Trojan 12v batteries. Go figure. I am not a fan of 12v golf cart batteries. Club Car gave up on them in 2008. EZGO doesn't put them in their other models. ??

I have an RXV with the 6x8v set up. It is a better cart than the 12voters. If you intend to keep the cart for a long time and battery range and life is important to you I would seriously consider the conversion to 8v batteries. It is an expense but not major surgery and you could probably do it yourself though I hear it can be a knuckle buster.

[kgsc]

Kernel not to question you but from what I have seen the price for 4 12 volts is about the same as 6 8s plus the new 6 battery rack or is extremely close. The new rack bolts in and can be done with the body on but is much easier with it off.

Part number for the rack was 627889 fwiw

[kernal]

Yup, I agree with all that. A service manger once told me the techs seem to curse a lot when installing the rack for 8voters in RXV's. Hence the knuckle buster comment.
Frequently a six pack of 8v's are cheaper than a 4 pack of 12s in my area and you get more capacity also. But prices vary a lot and can change weekly. Batteries are big business here.