2013 RXV State of charge drops to zero very quickly after reaching the 3/4 mark

[hully67]

I have 12 month old Trojan T1275+ batteries in my 48 volt RXV. I have had an ongoing issue whereby as soon as the charge indicator on the dashboard gets to around 3/4, it will then drop to zero very quickly (within a few minutes).

I have had the batteries tested and they all come up to full charge (sg ~ 1277 allowing for temperature) when charged individually. The current state of charge after a full cycle on the charger overnight is:
(with Battery charger disconnected - sitting idle)
All in series: 52.2
Battery1: 12.9
Battery2: 13.1
Battery3: 12.9
Battery4: 13.0
I charge the batteries with a DeltaQ 913-4810-E3B (algorithm 3 and wonder if it is not fully charging the batteries. I say this because in the 12 months I have had the new batteries, I have not had to top up the electrolyte in the cells more than once which in our climate is very unusual I think (I live in the tropics where the average daily temp is 33c/91f).
The batteries were on charge last night after using the cart for 18 holes yesterday. I went slowly all day which brought the charge indicator down to just above 3/4. When I drove home a little later (distance approx 750yards), I upped the speed and watched the meter drop to zero in the space of a few hundred yards. The cart continued on without the speed dropping despite what the charge indicator showed.
Anyone have any idea what could be going on?

[usgicollector]

First that charge indicator on the dashboard is not very reliable. Get this RXV Charge Meter it's plug and play and you'll see what your batteries are doing in real time.

[BobBoyce]

Correct. The SOC guage is a display unit that simply shows what the controller has calculated the battery pack state of charge to be. The new aftermarket SOC guage shows that, and an actual digital voltage reading of the battery pack while the cart is operating. It has a button that can be dash mounted to allow the selection of multiple modes. SOC%, Battery Voltage, and Hourmeter. The hourmeter counts the operating hours since installation. In all modes, a SOC bar shows at the top of the guage, above the digital readouts.

[Buggieman18]

The meter is the way to go. My stock SOC meter would do a similar dance, going from half full to a sudden yellow light, to barely making it home. My kids ran down the battery this weekend so I was able to see at what voltage you get worried. When it hit the alternating last two red lines it was running low 40'sV, and was a slow ride at 34V. Next time I run it down, I'll check the % setting to see where it lives. When I was crawling home, it read about 18%, so it needs some mental interpolation.

[hully67]

Many thanks for the replies. I just have one (maybe dumb) question:
After looking at the meter that the link took me to, it looks like it simply plugs directly back into the same wiring loom that the SOC meter that I currently have installed does. If that is the case, won't it just display the same information - ie won't it get the SOC information from the controller not the battery directly?
Alternatively, can/should I cut the loom plug off and wire it directly to the battery?

[usgicollector]

NO don't cut that plug you could blow the controller. The new meter is plug and play but the voltage readings will be right.

[hully67]

Thanks for the heads up. Much appreciated.

[cgtech]

The new meter offers the SOC from the controllers perspective, but also offers live voltage readings. That's where the value in it is.

[bdserv]

I am having this same problem - SOC meter drops rapidly from 1/2 to zero but no change in cart performance. Battery volts are all right around 12 volts and within 0.2v of each other when this happens - total pack volts right at 48v.

There was a link posted above to a drop-in digital replacement but the link no longer works. Anyone know which meter this would be?

[usgicollector]

EZGO RXV DIGITAL CHARGE METER