New Trojans Charging

[Camaro69]

Installed new Trojans T875 48v a little over 2 months ago.

Since then I've used the golf cart about 20 times and have fully charged it each time.

A few hours after plugging it in the in dash meter will jump to 100% and the volt meter will be about 64V.

By the next morning it will be about 85% and 51.5v.

I also made sure that I have the correct program downloaded in my ERIC smart charger for Trojans T875.

Is this normal?

If so, why would the % still not be at 100%.

[Fairtax4me]

Easy, Your dash meter is wrong. Don't look at any bar graph or % meters because they are notoriously inaccurate.

Fully charged Trojan T-875 batteries in a 48v pack are supposed to be 50.9v.
Usually with a brand new pack you can expect up to 52v to be considered a full charge and 100% SOC. Voltage measured 12 hours after a charge cycle has finished.
64v during charging or at the end of the charge cycle is just surface voltage and is not an accurate indicator of State Of Charge.

[CP241]

Ditch the meter and just get a voltage gauge. Or ignore the bar meter part of it.
Or, If the meter is programmable, you can set the 100% threshold to 50.9v and set the 0% threshold to 48.4v.” Since you never want to discharge past that point anyway. This will give you a more accurate reading, but not as you’re driving. You’ll have to read the percentage after you stop and let the cart sit for 5-10 minutes and it should be “close”.

As FT said, around 51v is fully charged. This reading is after the charger finishes, and shuts off. Then disconnect the charger and let it sit overnight. Your batteries and charger are fine

[Camaro69]

Originally Posted by CP241

Ditch the meter and just get a voltage gauge. Or ignore the bar meter part of it.
Or, If the meter is programmable, you can set the 100% threshold to 50.9v and set the 0% threshold to 48.4v.” Since you never want to discharge past that point anyway. This will give you a more accurate reading, but not as you’re driving. You’ll have to read the percentage after you stop and let the cart sit for 5-10 minutes and it should be “close”.

As FT said, around 51v is fully charged. This reading is after the charger finishes, and shuts off. Then disconnect the charger and let it sit overnight. Your batteries and charger are fine

Sounds good as I'm positive that my digital meter is programmable.

Will make the change tomorrow.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Maybe a new problem....Hope not.

When the batteries were charging this afternoon I noticed the dash digital meter was at 66v. Felt the batteries and they were warm, plus it sounded like water was gurgling (boiling)??? No sulfur smell.

Checked it later and it was still 100% but down to 55v and no water gurgling. So it's coming down after a full charge but the water situation can't be right.

Have the charger set to Alg03 which showed Trojan T875 48v.

Maybe a diff algorithm is better?

Thanks

[ojo]

Originally Posted by Camaro69

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Maybe a new problem....Hope not.

When the batteries were charging this afternoon I noticed the dash digital meter was at 66v. Felt the batteries and they were warm, plus it sounded like water was gurgling (boiling)??? No sulfur smell.

Checked it later and it was still 100% but down to 55v and no water gurgling. So it's coming down after a full charge but the water situation can't be right.

Have the charger set to Alg03 which showed Trojan T875 48v.

Maybe a diff algorithm is better?


Thanks

What you discribe is absolutely normal, ~ 65v in the final state of charging and some bubbling within the cells. When the charger shuts off, the voltage comes down immediately, step by step to 51-52v. Alg 03 (on a Delta Q charger) is the correct setting for
Trojan T-875 batteries also.

[ThreeCW]

Originally Posted by Camaro69

Maybe a new problem....Hope not.

When the batteries were charging this afternoon I noticed the dash digital meter was at 66v. Felt the batteries and they were warm, plus it sounded like water was gurgling (boiling)??? No sulfur smell

As ojo said, that is normal. See the Trojan charging recommendations below. As they note, for a 48 volt Trojan battery pack, a finish charge of 2.70 volts per cell or 64.8 volts for a 48 volt pack is recommended.

It sounds like boiling, but what is happening during the finish charge is the cells are "gassing" due to being intentionally overcharged as part of the charging process.

"Overcharging with high charging voltages generates oxygen and hydrogen gas by electrolysis of water, which bubbles out and is lost. The design of some types of lead–acid battery allows the electrolyte level to be inspected and topped up with pure water to replace any that has been lost this way."

Source:https://en.wikipedia.org/wiki/Lead%E2%80%93acid_battery

[ajs777]

Originally Posted by CP241

Ditch the meter and just get a voltage gauge. Or ignore the bar meter part of it.
Or, If the meter is programmable, you can set the 100% threshold to 50.9v and set the 0% threshold to 48.4v.” Since you never want to discharge past that point anyway. This will give you a more accurate reading, but not as you’re driving. You’ll have to read the percentage after you stop and let the cart sit for 5-10 minutes and it should be “close”.

As FT said, around 51v is fully charged. This reading is after the charger finishes, and shuts off. Then disconnect the charger and let it sit overnight. Your batteries and charger are fine

I need a meter for my cart, what is your recommendation?

[CP241]

Originally Posted by ajs777

I need a meter for my cart, what is your recommendation?

I’ve always just used the cheap digital volt meters from Amazon, they’re less than 10 bucks shipped to your door and work just fine.

[ojo]

I'm not happy with a cheap 9$ meter from China ( voltage reading is pretty wrong ), next will be the Murata DMR20-10 ( recommendation from here ).

[CP241]

I’ve used several variations of this meter… different brands but they’re all China brands and pretty sure they’re all the exact same company that makes the product.

Compared to my fluke they’re always right on. If you hook it up so it’s only on when the key switch is turned on, expect a couple tenths of a volt less than actual pack voltage though.

Automotive Authority LLC 48V Golf Cart Digital Volt Meter Battery Gauge for Use On Club Car EZGO Yamaha 48 Volt - Blue https://a.co/d/754nPzW