Battery Draining Quickly

polocheck

I have a 2009 Rxv that has 2014 batteries on it. I have a powerwise qe charger. I have taken care of these batteries making sure they maintain water and also replug in the charger every couple weeks or so during the winter months to keep the charge full. Recently I have noticed that after about 24-36 hours the pack voltage reads in the range of 50.4 with out being driven. Even when playing a round of golf the voltage drops down to the 60-70% range where previously was around 80%. I thought it was due to me not really using the cart during the winter months and it would help build capacity by driving short distances and playin a few holes, partially draining batteries vs a full rounds usage. I've also attempted to unplug and replug to get the batteries to take additional charge but doesn't seem like any of my methods are working.

Do you all have any suggestions? Do you think it's the charger and I should bite the bullet and get a DPI charger?

BGW

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kernal

Some quick questions to help everyone with diagnosis.
Are these 12v batteries?
Are they a matched set? Same brand, capacity and age?
Did you install them or do they have prior use by someone else?
Is cart garaged or stored outside?
What are the temps like where you are? Battery capacity is rated at 80°F. At 60° capacity is down 10-15%. There might not actually be a problem other than batteries haven't warmed up yet.

Take voltage reading under load if you can.

Any accessories recently added like a voltage converter?

polocheck

4 12v batteries
Matched set Trojan 1275 plus 150AH @ 20hour rate dated 3/14
I installed them myself
Garage kept
Central Arkansas area anywhere between 70-90 right now
Voltage under load is in the 42 range while accelerating and 44-46 when running on flat ground

No recently added accessories except swapped in new headlight but used my urgent wiring. I currently have a reduced with Bluetooth radio, lights, USB charger but those have been installed for over a year. Reducer is on a switch so it turns off with the key.

I did just watch to see what the voltage the charger turned off at and it was right around 64v.

teecro

You could stand with a higher finishing voltage 65, I'll double check when I get back to my computer tonight. But what your seeing is the main reason against 12 volt batteries is they simply can't store as much energy in the same basic space as an 8 or 6 volt battery...

JohnnieB

Here is a little something I put together comparing various Trojan 8V and 12V batteries in an RXV.

The T-1275 is the baseline the other are compared against for Lifespan, Range and Weight.

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Yes, a DPI charger is a good investment.

Attached Images

RXV 12V vs 8V Trojan batteries.jpg (189.9 KB, 0 views)

polocheck

Great chart! So do you think the the charger is to blame?

JohnnieB

Not entirely. The batteries are only taking about a 90% charge, so they are on their way out.
Probably due to sitting two weeks at a time in a partially discharged state.

Also, operating in temperature above 80°F shortens battery lifespan.

The DPI charger probably won't help the existing batteries, but will keep the next set at 100% SoC between uses.

polocheck

Thank you. Any tips on maximizing my current battery pack? With current charger and dpi charger. I know there's probably other threads around but since I have the attention of the man, the myth, the legend I'll ask directly.

teecro

I don't think you can go wrong with getting a NON-OBC 17-AMP DPI ACCUSENSE Battery Charger as it will get you the most out of your current batteries and when the day comes for you to replace your current batteries it will get you the most out of the new ones... Check out Scotty B or one of our other vendors as they have just about the best prices you will find on them... I keep my batteries plugged in 24/7 and recharge them even if I only used the cart for a few minutes...

JohnnieB

As for helping the existing batteries, I had pretty good results with a 36V set of T-105 batteries that would only charge to 85% SoC by back-to-back charging two or three times a day for a couple weeks. Went from 85% to 95% and then got better with less frequent back-to-back charges and float charging over the next few months.

If you have a manual 12V charger with a 6A to 10A max output, use it to charge the 12V batteries separately for about 6 to 12 hours each. Ideally, you want to charge each battery until the on-charge voltage stops increasing (IE: Increases less the 0.005V per hour.), so the on-charge voltage might climb as high as 16.74V if the open circuit output voltage of the charger goes that high.

Keep a close watch on the electrolyte level and temperature while doing these procedures. The batteries will gas a lot and get mighty warm. Keep the fluid level above the top of the plates and stop charging if the electrolyte gets above 115°F