Low run time for TXT PDS

[tfv0427]

I have a 2002 EZGO PDS that I bought about 4 months ago. The batteries were new at that time - they are three 12 volt Redline batteries. I can't find any specs on the batteries. Being a newbie to golf carts, I didn't know how to break in new batteries and just charged and drove. The batteries died completely a couple of times after just 2 or 3 miles. After doing some reading, I started doing shorter trips and charging after each use. I installed a DVM to monitor the voltage, which is usually about 38.5 or so after an overnight charge. I'm using a PowerWise charger that seems to be working fine. Lately, the battery life seems to be dropping. I take off strong and go for a mile or two, but then it loses power and just barely rolls home. The voltage goes back up to 37 or so when I stop, but when I hit the pedal it drops as low as 26.8. I'm wondering if my cart is just underpowered with only three 12 volt batteries vice six 6 volt batteries. Or if I did some damage when I first got the cart. Is there anything I can do to test, diagnose or improve performance. Thanks in advance for any advice.

[sportcoupe]

Welcome to the group.

You are correct, 3-12v batteries will not ever compare to 6-6v batteries for range.

I never heard of Redline batteries so I googled them. All I found were mototcycle batteries like this pic below. I don't think you can post a pic being new under 10 posts here. I could message you my email address and I can post the picture for you. Are your 12v batteries at least deep cycle or golf cart batteries?

RedLine website
http://redlinebatteries.com.au/

I hope your batteries don't look like this.

[tfv0427]

Thanks for the reply, Sport Coupe. The Redline batteries I have aren't from the Australian manufacturer, but from a local shop here in Florida. Here is their link:

http://redlinebatterysupply.com/

Not very helpful, though. I think the guy who sold us the cart had a friend there and got a good deal. They are deep cycle batteries, but I don't know what AH specs or anything about how they are made or quality.

[JohnnieB]

Please post a picture of any and all labels on the batteries.
I suspect they are marine batteries from a company in Australia rather than the deep-cycle batteries needed for a golf cart.

Even if they are true deep-cycle batteries, three 12V batteries only have about half the storage capacity as six 6V, so the run time will be lousy and the batteries useful lifespan will be short.

The voltage of a lead-acid battery drops when amps are drawn from it. How many volts it drops depends on how many amps are drawn, the battery's SoC (State of Charge) and storage capacity.

The battery pack voltage in the mornings is normal and unless the cart's drive system has been modified, the amp draw is typical for a PDS cart. That leaves the storage capacity of the battery pack being the culprit.

During routine operation, you shouldn't drop the pack voltage below 1.75VPC (Volts per Cell), which is 31.5V for a 36V pack, and never drop it below 1.50VPC, which is 27.0V for a 36V pack.

Irreversible physical damage of the battery plates starts occurring at 27.0V and you've taken your batteries down to 26.8V, so some damage may have already occurred.

Hopefully you weren't charged a premium price for the cart because it had "New" batteries, because what was done roughly equates to installing a "New" riding lawnmower starting battery in a full sized sedan with a V-8 engine.

With a proper battery pack (at least 225AH) a stock PDS cart will have a top speed of 18-19 MPH in Freedom Mode and have a range of 20 Miles or so.

With a proper set of batteries, good high current cables (4Ga or larger) and an Alltrax DCX400 controller, your cart will do 24MPH on stock height (18") tires. If you install seven 6V batteries (42V) instead of six (36V), it will do about 28 MPH and have a range of 30 miles or so.

[tfv0427]

Thanks, JohnnieB. I've been reading some of your helpful posts on cart batteries and that's kind of how I became aware that I had not treated the batteries right when we got the cart. I got a real good deal on the cart (says the buyer, of course, lol), so the "new batteries" were a bonus. Now that I've learned a little about carts and batteries, I'm starting to suspect the best bet is to invest in some good 6v deep cycle batteries. Just wanted to get a sanity check from the experts on this forum to make sure I wasn't missing something or heading off in the wrong direction.

[yurtle]

Being a cheap-skate, I'd run the batteries until they're unbearable before buying new ones. Get your money's worth. That's what I did. Batts aren't cheap, so go to ScottyB's website and Trojan's and learn as much about them as you can before buying new ones. Decide whether you want 48 volts, and if you do, decide whether you want 8 - 6 volts or 6 - 8 volts.

[JohnnieB]

A 2002 PDS is a good platform with a lot of on-road potential and some mild off-road mixed in.

My goal was range rather than speed or torque, but I ended up with a generous amount of all three.

You definitely need a proper set batteries and some good cables just to get the cart to stock performance and a 12 year old cart that might not have been maintained very well by the previous owner(s), may have some issues that are hidden by the lack of a proper battery pack, but now is the time to decided what you want to cart to do and build towards that goal as you fix what is wrong.

Bounce your thoughts and ideas off the folks here on the forum and learn from our mistakes.

[yurtle]

cartsunlimited.net has a good writeup on batteries, maintenance, and also on controller upgrades.