2012 48v Ezgo cart slow on incline

[Khmangels]

I have similar problem as earlier posts. My Ezgo golf cart is real slow on slight inclines. Checked all six 8 v batteries and they all test between 8.1 and 8.2 volts with digital meter. Check for all battery cables and they appear fine. Lifted up mat and checked/adjusted aluminun to ensure it passes through black tunnel. Took a short test ride and could barely get the cart up my driveway to garage-slight incline. Also tried it out on the streets and it ran great on flat or downhill surfaces but slowed dramatically on inclines...What else can I do???

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[scottyb]

Welcome to BGW

Batteries can show good voltage at a standstill but have little amperage stored. In this case the voltage will drop under load and performance will suffer. You can attach a meter to the pack and drive uphill and report back what the voltage reading drops to when the cart is slowing way down.
You can then repeat the test with the meter on each battery to see if just or all of the batteries are dropping.

Look forward to your live load test results.

[JohnnieB]

With all six 8V batteries reading from 8.1V to 8.2V, you batteries are from 53% to 65% charged, so the first thing I'd do is charge the batteries. A fully charged 8V battery reads 8.49V if it is a Trojan brand or clone.

The lower the State of Charge (SoC), the lower the batteries will drop to under load.

Also, Lead-Acid batteries store less energy when they are cold and as a consequence, the voltage drops more under load. Specifically, their capacity is rated at 80°F and they only have 50% of that capacity at 0°F. So for every ten degrees the battery temperature is below 80°F, the storage capacity is reduced by 6.25%.

Note: Batteries have a huge thermal mass, so it is the battery's temperature that counts, not air temperature.

What region of country are you located?

[Budweisr33]

Great info.


Sent from my iPad using Tapatalk

[ThreeCW]

As JohnnieB says, your batteries are starting out at a very low State of Charge (SOC) ... see the attached State of Charge chart for reference.

If charging does not improve your batteries to or very near to 100% SOC, you may have a battery problem. Note that the chart is based on a stabilized battery voltage ... after fully charging, disconnect your charger and take the "stabilized battery voltage" at 12 to 24 hours after disconnecting to determine an accurate SOC.

Once your fully charged SOC is determined, then try the load testing that ScottyB suggested.

And welcome to BGW!

[Khmangels]

I live in Virginia...Sent a new thread re voltmeter readings on incline versus flat surface. 49.7v right off charger; Once driven for ten to fifteen minutes slows 48.7 v but drops to 42.7 on incline.

[scottyb]

Originally Posted by Khmangels

I live in Virginia...Sent a new thread re voltmeter readings on incline versus flat surface. 49.7v right off charger; Once driven for ten to fifteen minutes slows 48.7 v but drops to 42.7 on incline.

I think your batteries have lost some of their capacity to hold a charge. Most chargers will bring a 48v pack to 57-63 volts at the cut-off point... THey we wait 12-24 hours to see what the pack voltage will settle to and this is the amount of voltage the battery pack can actually hold. This number should be 50.9-51.4 depending upon the battery and when it is read.

[Khmangels]

Okay, I will unplug the charger and test after 12 hours. BTW, there seems to be some conflicting info out there regarding charging Trojan batteries. The EZ GO golf cart manual suggests keeping batteries on the charger when not in use; however, the Trojan website indicates you should not keep them on the charger constantly. Which is true?

[JohnnieB]

Originally Posted by Khmangels

Okay, I will unplug the charger and test after 12 hours. BTW, there seems to be some conflicting info out there regarding charging Trojan batteries. The EZ GO golf cart manual suggests keeping batteries on the charger when not in use; however, the Trojan website indicates you should not keep them on the charger constantly. Which is true?

Both are true, but the Devil is in the details.

More correctly, if you post the exact wording from both sources, the specific meanings ought to become apparent, or at least the errors in the manual or website should.

For maximum performance and longest cradle to grave lifespan, cart batteries ought to be returned to a fully charged state after each use and then maintained at a fully charged state between uses.

[scottyb]

All modern chargers have an automatic cut off point built in. Meaning that when they reach a preset voltage the charge ends. There is no benefit or harm in leaving this charger plugged into the cart as once it's done it is off.
Some smart chargers then will go into a float or maintenance mode which is a very low charge which combats self discharge. A float charge is desirable for any lead acid battery with seldom use and charging.