Costco GC2 6 Volt Cart Batteries

[15clubs]

If I drive 1/2 mile to the course. play 18 holes (4 hrs or so and about 4 miles) with a passenger then drive home my Batteries are typically under 50% .

[15clubs]

Great Chart, I need better batteries, I am pushing the limit with these. costco batteries dont list all the comparable specs

Originally Posted by JohnnieB

Just so everybody is on same page, are you saying the batteries typically end up with a SoC (State of Charge) of 66% or 33%?
(Going below 50% is considered a no-no for battery longivity)

Attached are two charts:
The first showing SoC vs open terminal voltage and also includes Specific Gravity of electrolyte.
The second illustrates theoretical life expectancy vs average SoC.

Even if the typical SoC only goes down to 66%, you might consider going to a higher amp-hour battery when you replace your current set.
Of course, it would take some number crunching to determine if the higher AH batteries would be worth the higher initial cost.

[scottyb]

Originally Posted by 15clubs

Great Chart, I need better batteries, I am pushing the limit with these. costco batteries dont list all the comparable specs

Sort of makes you wonder, doesn't it. Everybody at the top of the capacity chart is anxious to show their spec sheet.

[JohnnieB]

Originally Posted by 15clubs

If I drive 1/2 mile to the course. play 18 holes (4 hrs or so and about 4 miles) with a passenger then drive home my Batteries are typically under 50% .

That's only about 5 miles and unless it is uphill both ways, I suspect there is more than just a battery issue.
My batteries are sickly (Only charge to 95%), but I get over twice that distance with about 500 pounds on-board without going under 60% SoC.

Which model cart do you have and what type drive? (Series wound motor or PDS/DCS)
Stock height tires, or taller ones?

Of course, if you are using a dash mounted SoC meter, it might not be too accurate, unless it is the DVM type.
Using a handheld DVM, what is the battery pack voltage before and after a golf outing?

Are any cables, components or connections getting hot? (Uncomfortable to touch)

-----

The specs used to compare 6V Golf cart batteries are:
Minutes at 75A rate
Amp-Hours at 20 hour Rate
Weight

Weight being the most important, since the manufacturers can fudge a little on the other two.

When comparing batteries of the same voltage, the heaviest one will have the largest storage capacity.

[15clubs]

06 PDS, 10" wheels but stock 18" diameter, 4 ga cables, while do have a SOC meter I do use a voltage meter. typically 6.14 volts on a battery when I get through playing, the bad one was only showing 5.9

[JohnnieB]

Originally Posted by 15clubs

06 PDS, 10" wheels but stock 18" diameter, 4 ga cables, while do have a SOC meter I do use a voltage meter. typically 6.14 volts on a battery when I get through playing, the bad one was only showing 5.9

Basically the same as what I've got, except for the cables.
What PDS mode are you running in?
Is there something dragging? (You ought to be able to sit on cart and move it with one hand on the ground.)

I get about 18MPH in Freedom mode and about 14MPH in Mild Hill. Never tried the other two.

I haven't quite made up my mind yet as to brand, but I'm installing batteries in the 250-260 AH range this coming spring and expect to get at least 25 mile round trips out of it over paved/gravel roads with some cross county on relatively mild terrain. New tires are on the to-do list also, but I'll be staying under 20" since 18-20MPH is plenty for my needs.

[15clubs]

I just changed bearings in the Motor, Motor input shaft and rear axles. Cart runs very nice,smooth and quiet and tops out at 19.5 using my GPS. Thinking of doing the Plum Quick Motor upgrade for $200 if I can get it up to about 22+.
How long are you arms?

[JohnnieB]

Originally Posted by 15clubs

How long are you arms?

I wear a 19.5x37 shirt size.
Kneel in front of passenger seat to reach ground.

If your PDS controller limits motor RPM to 4400 RPM like mine does, your tires stand about 18.5" tall.
Mine are 17.4" (Carlisle Links with little tread left and no traction)

I'm not sure if just having Plum Quick do their magic on your motor will increase the speed with a stock PDS controller. But I might be wrong.
Maybe somebody that knows for sure will chime in.

The problem is that the PDS controller has to have RPM information from the motor or it turns down the amount of current it passes to the motor and even with the info, it only allows a pre-programmed max RPM. If PQ used a speed sensor the put out less than 8 pulses per RPM to fool the PDS controller, it could go faster, but I don't know if they do that or not.

If you switch to an aftermarket controller that doesn't limit motor RPM, or limits it at a higher rate, it will go faster. If and when I blow my stock controller, I'll probably go to a 400A Programmable Alltrax and back off the top speed to about 20 or so.

[15clubs]

Thanks for the Information

[stuff]

FYI...iv'e bought Sams club batts for years. The first set went 5 yrs. This last set has stated to pass away at 3. I play 3-4 times a week. When im done the batts are way low! I do agree you get what you pay for,,but all in all iv'e had pretty good luck with cheap batts. I do take good care of them! JohnnieB has great ifo on batts. The next set i buy this spring i'm going to do the breakin procedure and see how my better service i get out of them My old "toaster oven" just keeps going and going. This is just my 2 cents worth!