RXV Voltage Drop on hills - 1 yr old US BATTs

[Mccoy38]

Hello all, Know this has been beat to death but my situation seems a little different. Looking for some direction on 48v RXV.

Purchased 4 new US 12v Batteries April 2018. Sill use PW charger. Have digital SOC meter. with digital bar. Cart has continually got worse and worse range since I installed them.

It has been well above 70* for over 3 weeks now. I have charged them independently on car charger to make sure they are charging fully.

SoC after full charge next day at rest voltage is 51.1v. Each battery is 12.83, 12.73, 12.83, 12.73 in that order.

I can play 18 holes with two guys and clubs but with only 45% left on the pack according to the bar on gauge (which I know is not all that accurate) but true pack voltage is also right at 48v sitting still. Drops lower as soon at any power is needed 45-46v range on flat concrete. I can get home but I would not attempt to play more.

Going up hills I have started to notice performance decline since I installed them, as well as critically low voltage drop across the pack. I have seen 43V going up hills early in the round and even lower later in the round, like 38-39v. This would be at full throttle but not much better at half either way.

I have never been able to get full specific gravity on any of these cells even right after full charge. May be due to temps.

All my accessories are running off 48-12v converter.

Trying to figure this out before I take all these batteries out for warranty replacement. They are heavy and if they test OK they will not replace them.

1) Do these controllers (2013) "get weak" causing this performance if pack is OK?
2) Do these motors "get weak" needing more demand?

I check water monthly and never under fill or over fill.

My buddy just had to get a lester charger b/c his PW failed and I was going to try it but all the voltages read out as if it is getting full charge.

Looking for some things to try before I pull these out. It runs strong while its above 75% (which isn't very long) but I should be able to play 36 holes + and still be strong with the RXV on 1 year old batts.

I do have it turned up to 19.5 but do not even get close to that on course.

I have not had a chance to test each battery voltage on hill climbs yet and is my next step probably. I just didn't not know the controller or motor characteristics if they are failing possibly. Thanks!

[cgtech]

The motor and controller do not degrade over time, requiring more power.

[kantuckian]

Interesting I have a 2005 precedent doing exactly the same time same age batteries like yours above will go 18 holes below that 15 holes.

[dougs_huntingcart]

What size tires do you run?
Have you checked the lugs at each battery for good connection/corrosion?

[dougs_huntingcart]

I saw the post you had back in December. Same cart? Same batteries?
http://www.buggiesgonewild.com/elect...ml#post1572064

[MUDSLINGER250]

I have 2014 rxv 48 volt with 4 12 volt us batteries. I bought my batteries in 2017 they were also doing the same thing be fully charged and run down pretty fast after charging. I have a quiq charger that came with my cart so it would charge the batteries but didnt have a float that would keep them fully charged if the voltage dropped any. I'm not sure if your chargers have a float mode or not. What I ended up doing was installing a timer to shut my charger off and power it back up to keep it charging since I have no float mode. After doing this my battery life increased exponentially. My cart stays at my farm so that's another reason I went with a timer itll shut off for 15 minutes everyday and turn back on recharging. I leave mine for a week or longer at a time. Not sure if this will help in your situation but it really helped my run time.

[bobbycason]

Originally Posted by MUDSLINGER250

I have 2014 rxv 48 volt with 4 12 volt us batteries. I bought my batteries in 2017 they were also doing the same thing be fully charged and run down pretty fast after charging. I have a quiq charger that came with my cart so it would charge the batteries but didnt have a float that would keep them fully charged if the voltage dropped any. I'm not sure if your chargers have a float mode or not. What I ended up doing was installing a timer to shut my charger off and power it back up to keep it charging since I have no float mode. After doing this my battery life increased exponentially. My cart stays at my farm so that's another reason I went with a timer itll shut off for 15 minutes everyday and turn back on recharging. I leave mine for a week or longer at a time. Not sure if this will help in your situation but it really helped my run time.

This is what we did with my Mom's Yamaha that had the same issue. Before finding this site we never knew anything about batteries and chargers so we just left it plugged in over the winter thinking the charger would keep them charged and realized that wasn't the case when we found completely dead batteries a couple months later. Now its plugged into an outdoor timer that turns the charger off and then back on so it starts charging again.

[Cobra,1]

How often do you charge batteries?
Charge after every use? Charge every 2-3 weeks when not used?
Should be able to get accurate spec gravity “with” good hydrometer regardless of temp.
Spec. Gravity will show a bad cell which will kill performance.
Read battery break in on Scottie’s site for good info on breaking of in new batteries

[Mccoy38]

Sorry for delay. Yes using PW and I use cart every few days. I run 18” tires.

I will try the timer method. My neighbor has Lester 2 im going to try as well. I’m getting up to 50.8v pack charge but I assume since it’s not floating that may be causing this issue. But I do unplug and replug every so often but not on the regular. I have two batteries that are 12.74v, one at 12.84 and one at 12.90 after 10 hours of resting from full charge. Going to put car trickle on all four to try and get them even and see if one of these low batteries are bad under load.

[Mccoy38]

Originally Posted by dougs_huntingcart

I saw the post you had back in December. Same cart? Same batteries?
http://www.buggiesgonewild.com/elect...ml#post1572064

Yes same cart and batteries. It has gotten better that that with the warmer temps. We are still seeing cool nights so I’m trying to hold off on changing them until we get constant warmer evenings. I am KY so I am probably only getting 70% of pack power to begin with at 60-70 deg garage temp.