Charger height

[Tony M]

This may be a really off the wall question, but here is the story. I have 6 month old batteries in a 2008 PDS cart and use a powerwise charger, normal charging time for me is about 2 hours or so till the charger shuts off. I have gotten so used to the charge time and repeatability of charging that I plugged it in to charge one night and did not check it until mid-day the next day and to my surprise, it was still charging and the voltmeter was reading 42 volts, the batteries were gassing off pretty good too. The only change that I made to this charge cycle was that I took my charger off of a shelf ( 7 foot off of the floor ) and placed it on the floorboard of the cart, and also used a heavy 25 foot extention cord to get power to it. My question is, does using an extention cord or lowering the height of the charger alter the charging cycle at all?

[JohnnieB]

Neither repositioning the charger nor using an extension cord should have altered the charge time.

The powerwise charger, specific model not given, probably has a safety timer, but the given length of time on charge is ambiguous, so it is not apparent if it exceeded the typical 16 hours.

Since the auto shutoff voltage is 44-46 volts, at 42V, the charger would stay on until the safety timer times out.

Unless somebody or something, somehow restarted the recharge cycle, you might have lost a cell coincidentally with moving charger.

What is the terminal voltage of each battery in the pack?
How many hours were batteries actually on charge?

Could be batteries, could be charger, could be cables, could be normal, could be a poltergeist.
Need more info and more specific info.

[scottyb]

2 hours is not a complete charge...... average charging time is more like 5-7 hours. Sounds like you are FINALLY getting the full charge. Which begs the question, why where you not getting a full charge before? If your cart connection cord was stretched it could have been loosing connection? This would have shut the charger off ....

[Tony M]

Thanks for the replies, I think that I am just now getting my full charge as well, I have noticed a significant improvement in battery performance lately.
I did follow the new battery break in procedure that you recommended, now I just hope to get 5 more years out of them.

[Andy4639]

Taking the charger off the shelf want matter.

Sorry but a drop cord pluged to the charger will make a differance. The less cord the better. The manufacture will even state this. If the cord is rolled up even can make a differance.


http://batterychargerdepot.com/Batte...20OM-WD-PL.pdf
CAUTION: TO REDUCE THE RISK OF FIRE,
USE THIS CHARGER ONLY ON CIRCUITS
PROVIDED WITH A MAXIMUM OF 20 AMPERE
BRANCH CIRCUIT PROTECTION (CIRCUIT
BREAKER OR FUSE), IN ACCORDANCE WITH
THE NATIONAL ELECTRICAL CODE, ANSI/NFPA
70, AND ALL LOCAL CODES AND ORDINANCES.
The use of an extension cord with the charger
should be avoided. The use of an improper
extension cord could result in a risk of a fire or
electric shock. If an extension cord must be used,
use a three-conductor, No. 14 AWG cord with
ground, properly wired, in good electrical condition
and keep it as short as possible. Make sure that the
pins on the plug of the extension cord are the same
number, size, and shape as that of the plug on the
battery charger. Locate all cords so that they will not
be stepped on, tripped over, or otherwise subjected
to damage or stress.

[Tony M]

I have a little more info now. My charger model is a powerwise QE, I plugged it directly into the wall outlet and 24 hours later it was still blinking long green flashes indicating that the charge is greater than 80%. It was still gassing the batteries and my in dash digital volt meter was topping out at 45.5, I figured that the safety timer should have shut it down by now so I unplugged it, any more thoughts?

[JohnnieB]

Let me see if I understand the situation correctly. Your batteries are 6 month old, they were only getting charged for about 2hrs previously, you repositioned the charger and now they are charging for a longer period of time, so you've noticed an improvement in performance. Now you've left them on charge for approximately 24hrs, the charger green LED is blinking long flashes indicating >80% charge, your in-dash DVM reads 45.5V and you unplugged the charger.

If it were mine, I would check the continuity of the battery sense wire in the output cable (smaller of the 3 wires) as well as clean and tighten the Aux. Contact in the output plug and clean the outside of the negative contact in the charger receptacle on the cart.

Then I would put it back on charge and while charging, monitor the voltage of the individual batteries. They should all be within about 0.1 volts of each other and none should be over about 7.8V (or 46.8V for the pack)

I'm guessing that either the batteries have never been fully charged and are just taking a long time to charge, which is typical for new batteries (but this does seem longer that usual), or one or more batteries have problems.

45.5v simply may not be high enough to shut off charger. May be close, but that is what the long flash of the green LED means.

Basically, I'd listen to what the charger is telling me after I made sure the charger was get good info from the battery it was charging>

[Tony M]

Your exactly right, I may be wrong on the 2 hour charge, it was more like 4 hours. I definately notice an increase in performance, a little more speed and lots more run time. I will clean the charger contacts on the cart and charger as well as the output cables and post the results, thanks for your help.

[JohnnieB]

Originally Posted by Tony M

----- I definately notice an increase in performance, a little more speed and lots more run time. ----

If you got a speed increase, your batteries were barely being charged.

What I mean is that a PDS (and DCS) controller limits motor RPM and after you reach that RPM, throwing more voltage and amps at it isn't going to increase speed (motor RPM).
Since you got a speed increase, the SoC (State of Charge) you were getting previously must not have been enough to reach the max RPM allowed by controller.

With a Freedom Chip installed, I get 18.2 MPH (Motor = 4,400 RPM) with 17.3 inch tire diameter, stock differential ratio (1:12.44) and 2 yr old T-105 batteries.

Here is a State of Charge chart. The readings are taken after the battery has "rested" several hours (IE: 12 or more) after charger shuts off automatically, or several minutes after being driven a mile or so.

The 45.5V you read right after the batteries were charged was a "Surface Charge", which rapidly depletes. Since your batteries are relatively new, 100% SoC voltage might be slightly higher than listed.

[Tony M]

My batteries have definately achieved 100% charge. 24 hours after I unplugged the charger and driven it a little, it was at 38.4 volts.

I have the dial selector chip, when I put it on freedom I loose my regen. braking so I use the steep hill chip mostly. I have a copy of that SoC chart glued underneath my seat, I followed Scotty's battery break in procedure to the letter, so I guess the performance increase that he referred to has finally made it's way to my batteries. I just don't want to hurt them by overcharging, especially if it is caused by a dirty connection or something.