New Batteries

[EZduzit101]

I just had 6 new Trojan T-605 batteries($1000)installed in my cart, along with all new cables. I am using the charger that came with the cart(Total Charge III). During charging I am getting a reading of 45 volts, and it is taking well over 24 hrs to charge. Should it take this long to charge? After I disconnect the charger, I get a reading of around 39 volts, but this only gives me about a day of running around on my flat terrain property then I get a reading of 37 volts! Isn’t 37 the magic number to charge it up again? In the past, I’ve gotten several days of service before I have to charge it up again. Can you tell me what the problem could possibly be? Defective batteries?
I am an older woman that really needs this cart to get around. Coughing up the money for new batteries was difficult, but I figured cheaper than buying a new cart of any kind. You guys have always helped solve problems for me over the years and I sure could use some advice. I will wait for replies before I have any discussion with the golf cart repair man. Thanks in advance.

[CustomCurt]

ride it around some and then feel around the wires and such to see if any are hot, also it should probably go thru several charge cycles

[Reddawg454]

To make your $1000 investment last as long as possible you should charge your batteries every day you use the cart. No matter if you drive it 500 feet or 5 miles put it on the charger when you are done for the day. As Curt said the new batteries need to be charged multiple times before they reach their peak capacity (breaking them in). I think 45 volts peak voltage while charging is acceptable.

[EZduzit101]

Thank you both for responding to this post. I am encouraged! The golf cart repair man NEVER mentioned a “break in period”....so thank you for that bit of info.
I will share with you the info after I posted last night. The charger finally shut off last night after 36 hrs. The DM reading was 38.9 volts. This morning after the batteries and I rested(LOL) the DM read 37.4 volts. I checked each battery and got a DM reading of 6.2 volts.
I then did a ?load test? Where I jacked up the rear of the cart, had someone depress the accelerator and I took a reading of each battery, which turned out to be 6.1-6.0 on each battery. Does all of this sound correct so far?
I am planning on going out here in a few minutes and drive it around and get some of my chores done. That’s all I have for now. I WILL plug in the unit every time I am through with it and see what happens.
Thanks in advance for your help.

[kgsc]

37.4 is low but they need to charge a few more times.

[EZduzit101]

Thank you for that info. One last question...how long does this “break in period” normally take ? Thank you.

[kgsc]

That varies but just charge it completely every night and don’t let the batteries get below roughly 80% the first 10 charges or so.

From one of the sponsors https://www.cartsunlimited.net/battery-break-in-.html

[Threeput]

If I didn't install the batteries myself...first thing I would check is the Electrolyte (water) level

[ojo]

24/36 hrs for a full charge is too long, i guess. Usely 6 - 9 hrs, but 36? Seems to be a problem either with batteries or with the charger. My experience with new Trojans beside the break-in-periode, they reached their full voltage from 1st day on. Wondering why use T-605 batteries instead of common T-105, maybe wrong curve for that type?

[JohnnieB]

Need to get some valid At-Rest voltage readings for SoC estimates.

The voltages listed on the SoC chart are taken about 12 hours after the charger shuts off or about an hour after the cart has been driven. Otherwise the battery voltage will be artificially high, or artificially low respectfully.

A new battery only has about 75% of its rated storage capacity and it takes about a hundred charge cycles to reach its rated capacity, but most to the storage capacity increase occurs in the first two dozen cycles.

Also, temperature is a major factor in storage capacity. The rated values are at 80F and the capacity decreases roughly 10% for every 20°F below 80°F and batteries have a huge thremal mass, so use the previous night's low as the battery temperature when calculating storage loss due to being cold.

The Total Charge III is very old technology and shuts off when the On-Charge voltage climbs into the 44V to 46V range rather than truely fully charging the battery. Modern charge that use dV/dT (Change in Voltage over Change in Time) technology to fully charge batteries and the On-Charge voltage climbs a bit higher.


ojo is right about new batteries having full voltage, however the voltages given may have been skewed by having been taken too soon after charger shut off or too soon after cart was ridden.

On the other hand, the first charge on some new batteries can take 20 hours or more. It depends on the time lapse between when the batteries were made and and when the were installed. The longer time they spend in the supply pipeline, the longer the first charge takes. (36 Hours is mighty long)

If the charger hasn't shut of by the next morning after a few charges, then there is something wrong with charger or batteries, or the charging circuit.