Battery Questions

[sunking]

Originally Posted by bdmonist

So the way to go would be a 48 volt system running 8 6 volt batteries right? Anyone done that? I'd sure like to know how to make them fit...

They fit right in place as the 6 volt batteries as the T-875 are the same physical size.

[sunking]

Originally Posted by divnkd101

Next question... regarding battery life, would switching to 8 batts tend to extend battery life if maintained properly?

Ok you gotta be careful here and understand something real important about lead acid batteries. You never ever want to discharge a lead acid battery more then 50%. Otherwise you will significantly shorten the battery life. If you really want long life never discharge more than 20%.

So with this mind, alays recharge the batteries after any use, and never let your batteries remain in a discharged state for any length of time. Leaving a battery in anything less than 100% fully charged will shorten the life by sulfation. Sulfation accounts for 80% of all battery premature failures.

[ajbrown]

Originally Posted by bdmonist

Aj - Are you putting your 2 extra batteries in the bag compartment as well? Or something different?

We had two thoughts. The first was an idea I had because we do not do metal fabrication or aluminum welding.

1. Build a tray above the motor to hold two batteries. This would require a small cut to the body as the batteries come above the body and do not fit through the controller acess panel. Our plan was to hide the batteries by buidling a small box under the basket. It would look like someone intentially built a "lock" box under the basket if done right.

2. Find some local shop (The Villages, FL) to fabricate us a center tray to hold 4 batteries. This is the way I have seen it done by others.

In both solutions the controller needs to be moved and we would install a battery fill.

I say "we" as this is a father son project (I am the son, the father is the smart one )

[scottyb]

It is best for battery life if you can have access to regular maintenance of cable ends....

[bdmonist]

Scotty- it appears you have been around these things for a while. Where have you generally seen tha two extra batteries placed?

Also - Is there any problem using the 48 Colt Charger as usual, or will adding two batteries in there "confuse" the OBC?

Brian

[ajbrown]

When I first came on BGW I read hundreds of threads. In one of those was three pictures of a tray someone built. I saved the picture, but d*mn if I can find that thread now. It was nicely done....

The only thing I would change from those picture is that I "think" I can fit the additional batteries without moving the tray forward 2 inches. When you do that you need to cut into the frame which makes me a bit uncomfortable. I have seen a DS locally that achieved adding the new tray without cutting the frame for the tray.

To be clear I am very inexperienced, but have seen 3 Club Car DS series with the 8 6 v batteries and all of them enlarged the center tray to hold 4 and moved the controller.

So whoever provided the pictures of their tray, thanks, but darn if I can find the thread now

[bdmonist]

I assume you would need to fabricate some type of tray regardless in order to have them secured in the Bagwell. I think you would also need to cut out some of the bagwell too. I measured the batts and bagwell and they won't quite fit without sticking out the bakc unless some plastic is trimmed towards the front...

[pansser]

i have an ezgo limo. the controller is moved to the frt seat and the two extra batts are mounted outboard of the main batt pack , in frt of the wheel wells. this was done at the factory. so if you were to move your controller could you do the same?

[sunking]

Originally Posted by ajbrown

6 x 8 x 170 = 8160 (old) versus 8 x 6 x 225 = 10800 (new) which looks like an additional 13ish miles. This is a handy formula to have to describe range. Thanks!

You can simplify, and things are even clearer Just take the nominal battery voltage of 36 or 48 volts, and multiply by the battery Amp Hour rating. That gives you the watt-hour capacity which is the true measure of a battery system. Amp Hours do not tell the whole story, only half of it.

Now this will blow your mind until I explain it. I just finished helping my neighbor convert his 36 volt cart to 48 volts. We used 100 AH batteries at 48 volts nominal. Here is the kicker with his 100 AH 48 volt battery he can go further than any of you with 8 Trojan T-105's and given the same motor and controller will go faster than yours guaranteed any day of the week.

The Trick is he used Lithium Ion Phosphate batteries. LFP batteries do not have the limitation of 50% DOD, you can take them all th eway down to 100% DOD with no shortening of battery life. In addition LFP do not exhibit the Peukert Effect that plagues Lead Acid batteries. Once you apply all the de-rating factors to lead acid batteries your 225 AH Trojan is widdled down to 65 AH of usable capacity.

In the speed department, th eLFP is 14.4 volts nominal in a 12 volt stack vs 12.6 in a lead acid pack. So the extra voltage gives you extra motor RPM's or speed. Next is weight and space. The LFP pack weighs 1/3 of the LA and only takes up half the space. So you get a little more speed from weight savings.

The last plus is th eLFP have a very flat discharge voltage curve. That means it goes just as fast at full charge as it does before it craps out. The bad thing is once you notice a slow down, it is too late you got about a block or two distance left, But who cares with a theoretical range of 32 miles per charge.

Oh yeah price suks, it set him back $2400 for the battery plus another $500 for the charger.

[scottyb]

I will take some doing to but the extra batts in there, that is why most go with 6 8v.