Battery problems

[JohnnieB]

Originally Posted by Big matt

1. On a side note I charged batteries when I first bought them but didn't know there was anything else to break in on them.

2. I have also never taken them below half charge on meter.

1. New batteries only have about 75% of their rated storage capacity unit they have been "Matured" (Broken -In).
Probably too late to do it now, but Scotty has some good info about it on his website:
http://www.cartsunlimited.net/Batter...n_Methods.html

2. What kind of meter, State of Charge or DVM?
* SoC meters are sort of like fuel gauges, better than guessing blind while traveling, but no good for troubleshooting.
* Dash mounted DVM are far more accurate, but they can be confusing because battery voltage sags under load and then recovers after resting.
If you have a Dash mount DVM, let batteries rest at least 10 minutes before taking a reading.

You'll need a hand held DVM that has at least two digits to the right of the decimal point (0.01V) in the 6-7V range to check the batteries.

[Big matt]

Back from hunting trip and did part of test
1@6.52
1@6.50
1@6.51
1@6.51
1@6.39
1@6.38
Not sure if the two that are at 6.3 are the bad ones or are the other 4 over charging. Do I still need to do other test and if so need to wait for weather to clear. Thanks for help

[simple man]

Originally Posted by Big matt

Back from hunting trip and did part of test
1@6.52
1@6.50
1@6.51
1@6.51
1@6.39
1@6.38
Not sure if the two that are at 6.3 are the bad ones or are the other 4 over charging. Do I still need to do other test and if so need to wait for weather to clear. Thanks for help

Do you per chance have 12V lights running on the two batteries that are lower than the rest?

[Big matt]

Originally Posted by simple man

Do you per chance have 12V lights running on the two batteries that are lower than the rest?

No sir! I have my 12volt lights, cig plug and radio are all hooked up to marine battery.

[JohnnieB]

Originally Posted by Big matt

Back from hunting trip and did part of test
1@6.52
1@6.50
1@6.51
1@6.51
1@6.39
1@6.38
Not sure if the two that are at 6.3 are the bad ones or are the other 4 over charging. Do I still need to do other test and if so need to wait for weather to clear. Thanks for help

I take it those are the voltages you have about 6 hours after you charger automatically turned off.
If so, letting them rest only 6 hours probably isn't long enough.
Some battery manufactures say 6 hours, some say 12, some say 24 and others don't say anything at all.
I get about the same readings on my battery pack at 6 hours after the charger shuts off as I do at 12, so I said at least 6. My Bad.

Here's what's happening. A typical 36V automatic charger doesn't shut off until it senses battery pack voltage in the 44-46 volt range, or 7.3 - 7.6 volts per 6V battery. That last volt or so above about 6.37 is a "Surface Charge" and depletes rapidly, so it isn't a good measure of how much energy is stored in the battery and to get a reasonably accurate and repeatable idea of how much energy is in the battery, you've got to get rid of the surface charge. Flooded lead-acid wet cells self discharge, so you can wait until they self discharge the surface charge or use the battery for a short period of time to deplete it.

Newer batteries will track a bit above the voltages on the SoC charts, older batteries will track a bit lower. The fact that the Min/Max spread is 0.14V is a warning flag, but it is a yellow one rather than a red one. More testing is needed.

IIRC, your original concern was that your battery pack went from a full charge down to a half charge in a half a mile.
That could be a battery issue, a SoC meter issue or something else entirely.

So far we know with reasonable certainty that your battery charger is working and you've got two batteries not taking as much charge as the other four when subjected to the same charging current over the same amount of time since they are connected in series. However, we don't know if this is something new or if they ever took as much charge as the other four, unless you jotted down the battery voltages when they were first installed.

What is needed are the battery voltages immediately before the cart is driven and about 15 minutes after it has been driven until the SoC meter says the batteries are half charged.

If the voltage of any battery or batteries is/are significantly lower than the rest, they are probable bad.

If the SoC meter does not match the SoC chart for total pack voltage, it is inaccurate and needs to be replaced, or you have to learn how much windage you have to dial in mentally to get it on target.

While the weather is too foul for riding around the neighborhood (but not too foul for hunting ), you might try putting your fully charged battery pack on charge a half dozen times or so to equalize the batteries a bit.

Let us know what you find,
John

[simple man]

I have found that the new battery break in procedure will help older batteries also. I used it on mine and it helped considerably! I would do it even though you've used your batteries. I'd do what " JohnnieB " suggested first, because if you do have some bad batteries, it is best to find that out before doing a rather lengthy procedure!