Alltrax Conroller vs New Batteries

[m.childers97]

Hi eveyone! I have a question that I hope I can get a few opinions on. First off, I have a 2008 EZGO PDS with original 2008 Trojan T-105s in it, six inch axle lift, 20 inch knobby tires, rear seat, and speed chip. I bought the golf cart last year from a golf course so i assume it was well maintained. Ok, so my question. Should I go ahead and replace the batteries now or would I be ok to upgrade the controller to an Alltrax DCX400 and HD seleniod and get by for a couple more years? The battery pack after a full charge and just ten minutes of use reads as follows: 6.29 6.42 6.43 6.27 6.31 6.35 which I think equals to 38.07. I have decent run time its just the bigger tires took away a lot of torque that was used for hauling the wife and kids around. Any opinions would be appreciated. Also I have a 4 guage cable kit on its way as the cart has still has the stock 6 guage on it.

[JohnnieB]

The first thing I would do is try to balance the battery pack.

If you have a 6V charger, charger the four batteries with the lower readings up to an on-charge voltage of 7.5V.
If you can only lay your hands on a 12V charger, connect the two batteries with the 6.2x reading in series and bring them up to an on-charge voltage of 15.0V and do same to the two with the 6.3X voltage readings.

Then switch to your 36V charger and charge the pack several times without discharging it. (Keep an eye on fluid levels, they are going to gas a lot)

Hopefully, that will get them all within 0.1V (or less) of each other.

If so, I'd go with the controller, solenoid and cables for now and start putting money aside for a new set of batteries about a year or two down the road.

[m.childers97]

OK. I will give that a try. How long might it take to get each set up to the 15 volts ?

[JohnnieB]

If the 12V charger puts out 10A, it'll take around 5 hours for the set at 6.2x volts and about 2.5 hours for the set at 6.3x volts.
If the charger only puts out 5A, the times will doubled, if it puts out 20A, the time will be halved.

[m.childers97]

OK thanks for your help.

[m.childers97]

I guess I did have a 6 volt charger that puts out 6 amps and so far the voltage is up to 6.55. Think maybe another hour or two charging will bring it to 7.5?

[m.childers97]

I could only get each battery up to 6.55 to 6.67. And that was charging each for 2 to 3 hours. I guess those four batteries are the on their last leg.

[JohnnieB]

Technically, a lead-acid battery isn't fully charged until the Specific Gravity of the electrolyte ceases to increase while a charging current is passing through it, but the open circuit voltage tracks the SG pretty well and can be used as an indicator.

Charge the batteries until the on-charge voltage ceases to rise. That is pretty hard to do without sophisticated test equipment, so check every hour and stop when the increase is less than .004V from the proceeding voltage check. (That is the dT/dV rate looked for by some of the microprocessor controlled charging systems)

If you don't have a voltmeter that will read the individual battery voltages in Milli-volts, just let them charge overnight. A 6A charge rate for 12 hours wont hurt a 225AH battery.

Do this several times. The max voltage will increase some each time it is done.

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My "L9" T-105 batteries would only charge to about 85% SoC when I got my 2008 PDS and after charging the living daylights out of them for two months, they would charge to over 95% SoC, and improved some more over the next year since I upgraded to a charger that float charged after the regular charge cycle completed.

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Yes, your batteries are nearing the end of their useful life, but they ain't dead yet and with some TLC, you ought to get another year or two out of them, maybe more.

When you do have to replace them, replace all six at same time, charge them prior to first use and break them in properly to get maximum capacity.
Here is how: http://www.cartsunlimited.net/Batter...n_Methods.html

[m.childers97]

So just to make sure, charging the whole pack over and over with the ezgo charger can't hurt them either? Just keep an eye on the water levels. It seemed as if each battery stalled out gaining any charge after an hour so I took the 6 volt charger off and moved on to the next one

Over the next week I will charge the pack fully then rotate which battery gets the six volt charger to try and boost each individual one up. The charger does have a 12v setting but it only charges at 6 amps so I think I would be defeating the purpose of doing a series charge. End of the week I will post the voltage and see how its done. Thanks for your help JohnnieB

[m.childers97]

I have one of those Power wise Qe chargers also. I think max output is only 16 amps