Near New Batteries draining quickly?

drhill

Hi, I started a new thread because my old one turned into a voltage reducer discussion, which is cool.

I have a 2013 EZGO RXV

I disconnected my reducer and have been testing the rate of discharge of my 4 12volt US Batteries. Starts out with full charge about 51 volts. after 24 hours, it was at 50.2/50.3. After another 12 hours (36 hours total sit time) it was at 49.7.

This seems like excessive discharge...any thoughts? No other accessories running hooked up that I can see and I did disconnect my crappy voltage regulator.

BGW

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Sergio

Test each battery individually to identify if it is a "pack problem", bad battery, or not charging all batteries.

If all batteries are down equally, disconnect the main pack positive cable after a full charge and check if the batteries still loose voltage.

drhill

good idea, Can I pull the main pos and main neg after charge? I always like pulling neg first for safety!

I did actually check each battery and they were all the same voltage.

Sergio

Yes, you can disconnect both pack positive and negative.

drhill

Ok, fully charged pack, waited until it stabilized at 51.0 volts. Checked it again about a day and a half later (36 hours) and it was at 50.2/50.3. Is this a normal drain or still too much?

Also - looks like something in the system is still taking some battery power now that the pack is draining less with everything disconnected?

catmcaw

I'm not an expert but i just went thru the tryin to find out whats going on with my batteries deal. I think the only way to check the true condition of a battery is checking it under LOAD.

Cobra,1

Just throwing this out there. Water levels good,terminals clean are batteries clean like no dirt corrosion , ect on surface of batteries? Battery charger set up for those batteries. Example was charger originally set up to charge xyz amp batteries but new batteries have different amp hour specs and may not be fully charging/ balancing batteries?
Hth 😊

JohnnieB

If the 51.0V was measured about 12 hours after all charging ceased, than your US Battery brand batteries are not being fully charged. (51.00 = 94.4% SoC)

50.3V is 82.0% so the SoC decreased by 12.4% in 36 hours. or 8.3%/day.
Typical self discharge is about 1%/day.

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If you US Battery batteries have been chronically undercharged since birth, they may be in ill health, but may partially or fully recover with repeated full charges.

Here is a SoC chart for US Battery brand lead-acid, wet-cell, deep-cycle batteries

Attached Images

USB SoC 36-42-48V.jpg (176.8 KB, 0 views)

drhill

Interesting chart - specifically for US batteries. Yes, the 51.0 was after less than 12 hours, more like 2 hours after charging finished. I have the Delta Q charger that came with this cart. any way to check if the charger is doing its job?

I have been charging every couple of days and not even driving it the past week or so, so hopefully I'm getting it to fully charge. I know I checked them all during charging last night and they were 15.9/15.3/15.3/15.9 when almost fully charged. The 15.9 batteries were the first and last in the series and they were both gurgling during charging. I'll charge again tonight and pay close attention to the pack and individual battery voltage just after charging, after an hour and after 12 hours. I can also do pack and individual load tests on a hill nearby if that would help diagnose?

Thanks!

Fairtax4me

Do you have the QuiQ charger?
Many High Frequency chargers need to have the charge profile updated if you change batteries. The new batteries may not be charged properly by the profile that's in the charger.
The QuiQ series chargers can be updated but only with special connection adapters that it seems only dealers have.

You may want to get a new more modern charger that allows you to change the profile yourself.