A Battery Question

skyriver

Hello all, I have a question. I've just purchased 8 new Crown 260 batteries for my Ezgo cart and I'm using a Lester Summit 2 1050w charger. My question is about the voltage that the charger is taking the batteries up to before being fully charged. The voltage on the 8 batteries is going up to 66.5 volts before the green light comes on. 66.5 divided by 8 is 8.3125 volts per battery.

I called tech support at Lester and the technician said that it was normal and that the charger was just taking the amps up to 22 amps. I just doesn't seem right to me to go so high on every charge. Hopefully someone here will have some ideas on what is going on.

Thank you much

BGW

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kernal

My Lester links charger has been taking my Trojans to that high for almost 31/2 years. Batteries are still very strong. Current delivery is very low at that voltage level. This has come up before and if I remember correctly one of the members here called Trojan about it. They said it was fine.
I think this is the new normal for modern chargers.
I assume you set up the Lester specifically for the brand and capacity or your batteries as per the manual.

This is the Club Car section so some posts may be different than you expect. I think late model Club Cars with OBC's run the volts up that high also. I can't comment on Club Cars with the ERIC chargers.

skyriver

Thanks for your info Kernal, I didn't do any special setup on the charger, it's a onboard and I just connected it and turned it on. I did look through the manual, but didn't see anything that I thought I need to change.

At 260ah, they're not the normal golf cart setup. I'm glad to hear yours is charging the same way, I've just never heard of such high voltage. A normal Equalize Charge is only 64 volts, this is all new to me.

Apologies for adding this to the wrong thread, I'd appreciate other ideas and opinions as well.

ThreeCW

I don't have anything for Crown batteries, but here are the Trojan charging voltage recommendations attached below. During the finish charge, 64.8 volts or 2.70 volts per cell is the Trojan spec.

Trojan Charger Voltage Settings - 2015.JPG

kernal

You can download the Lester charger connect app from the app store or google play. Then go to this link: https://lesterelectrical.com/product...chargers/#info and scroll down. Click on the "app guide". These are the instructions on how to use the app. With the app you can set the charger up for your specific brand and battery capacity. The theory being the charger will use the correct finishing charge etc for the exact battery you have and not some generic setting.

Note: you have to be standing very close to the charger for the bluetooth connection, within about 10 feet in my case. The 3 lights on the charger will flash while its connected when mounted off board. I don't know about on board.

JohnnieB

By definition, a lead acid battery is not fully charged until the SG of the electrolyte ceases to rise while there is a charging current flowing through it. Since the battery's terminal voltage tracks the electrolyte's SG, it can be inferred that a lead acid battery is not fully charged until the on-charge voltage ceases to rise while an charging current is passing through the electrolyte and this fact is the basis for the charge termination criteria of the modern golf cart chargers.

They use a process called dV/dT (change in Voltage over change in Time) to determine when to end the charge. In other words, when the on-charge Voltage's rate of increase slows to a predetermined rate, the charge cycle is ended.

I don't have the dV/dT specs for Crown or Trojan, but for US Battery it is 4mv/cell/hour. For a 48V pack that translates to a rate of increase of 0.096V/hour.

This process still doesn't "fully" charge the batteries (the rate of increase would have to be 0.000V/hour for that), but it comes a lot closer to it than shutting off a specific voltage like the ferroresonant transformer type chargers of yesteryear did.

skyriver

Thanks for all the info guys. My son downloaded the app and we checked the settings and it had already recognized the proper settings for the 260 ah crowns batteries so I guess all is well with the way that it is charging.

It seems to charge well, just 2 -2 1/2 hrs from 80% charged. I try to never let it get any lower that 80%.

Thanks again for all the help.

CartsRFun

Hi Skyriver how are your crown 260 ah batteries working out?

What kind of run times are they yielding for you with a conservative dod?
Also are you able to determine distance traveled between charges?

Reason in my asking is I have ordered the crown agm crv260ah for my Star
Serius 48v ac cart, and was wondering what to expect. More or less.

I chose the agm version for zero maint., lower back problems have limited
what I can do.

Thank you for your reply

CartsRFun

Forgot to say I have the Lester Summit 2 650 watt charger and use the app.

skyriver

So far I'm not very happy with them, at least compared to Trojans. They've been in the Ellis battery service shop where I purchased them for the last couple of days, but they say they can't find anything wrong with them.

Hydrometer readings are good and they charge up well, but when the surface charge is gone they're down to 50.45 on the volt meter. 50.45 divided by 8 is 6.3062 so when compared the Trojan charge scale of 6.37 they're only holding a 90% charge, after paying $1300 for them I expected better.

They're telling me that they are at 100% charge and I'm not happy. A good strong 48 volt pack would settle at 51 volts. I also purchased 8 CR-235's from them for my other cart about the same time and they're good holding at 51 volts.