Battery life question

[shrpshtr]

Alright all,

I am getting a little aggravated about my cart's battery performance. On a full charge, I can only go about 3-5 miles cruising (read almost continuous running) before the batteries almost drop off almost completely. The drop off is sudden also. It's almost like things are good, then within a 300-500 yard distance, performance all but disappears. Without getting into too much detail about the current batteries I am using (Datacenter UPS battery re-purposing project), what should i expect to get "performance-wise" out of a good set of batteries? the trojan t-105s i had when i first got the cart were only 2 years old and didn't last me another year before they went to crap. i would like to be able to ride this cart around for the better part of a day without having to charge it. Is that an unobtainable goal or not too much to ask?

cart details in sig. thanks in advance.

shrp

[JohnnieB]

What you are asking is sorta like asking how far a car will go on a tank of gas.
The answer depends on the MPG the car gets and how many gallons the gas tank holds.

Without discharging the 42V - 245AH battery pack below 50%, which is the recommended max discharge limit, my cart's average range is over 30 miles, but that is only a bit over an hour's run-time with my foot on the floor since my cart will be doing 28 MPH. On the other hand if I drive the 30 miles in segments, I can be out and about for the "better part of a day" without recharging and if I drive at more efficient speeds, the actual pedal time increases, as does the range.

It boils down to how far your cart travels per kWh of energy and how many kWh of energy can be stored in your battery pack.

But to answer your question, what you want to do, is most likely doable.

[Sir Nuke]

With a good battery pack, with quality batteries.....all charged up and properly broke in..... just like Johnnie above.....my cart has roughly a 30 mile range.

[shrpshtr]

Ok, great. So let's tear this thing apart and figure out why I am getting such poor performance. What kind of information do I need off of the batteries to determine where I am at right now? I don't see the usual aH rating on these batteries as they are designed for Data Center UPS(s).

shrp

[scottyb]

Most likely you are not using golf cart batteries. Deep cycle batteries don't perform well or long in golf carts.

Can we get some simple voltage readings on the pack as you ride ?

[Sir Nuke]

well I have not been able to find anything that shows that these batteries are suitable for cart use. THUS, I am guessing that although they are the right or suitable size and voltage.....they are not actual golf cart batteries......which may be the root of your problem.

can you tell us where you got them? do they have a website?

[shrpshtr]

Oh yeah, I definitely know they are not designed for golf cart use. I know a guy in the large UPS (technology data center size) business who says he's seen great performance out of batteries he's re-purposed. I, unfortunately, am not realizing the "great performance" he was referring to thus far. So, I've come to terms that I'm more than likely going to have to replace the batteries. What I don't know is what else I can do to get the performance I am looking for out of this cart. I was experiencing similar performance with t-105s that were less than 2 years old when i first acquired the cart.

scottyB,

I'll try to get a reading for you this morning on the pack under load. Thanks.

shrp

[JohnnieB]

Post pictures of any and all labels and markings on the batteries.

What is the tire height?
Measure them, the numbers embossed on the sidewalls are very, very approximate at best.

What is the max inflation pressure stamped on the tires?

What controller are you using?

[mack Courtney]

Originally Posted by JohnnieB

Post pictures of any and all labels and markings on the batteries.

What is the tire height?
Measure them, the numbers embossed on the sidewalls are very, very approximate at best.

What is the max inflation pressure stamped on the tires?

What controller are you using?

Good questions JohnnieB, on a stock EZGO what tire pressure should we run for good distance? Close to maximum tire manf recommended?

[JohnnieB]

Originally Posted by shrpshtr

Oh yeah, I definitely know they are not designed for golf cart use. I know a guy in the large UPS (technology data center size) business who says he's seen great performance out of batteries he's re-purposed. I, unfortunately, am not realizing the "great performance" he was referring to thus far. So, I've come to terms that I'm more than likely going to have to replace the batteries. What I don't know is what else I can do to get the performance I am looking for out of this cart. I was experiencing similar performance with t-105s that were less than 2 years old when i first acquired the cart.

scottyB,

I'll try to get a reading for you this morning on the pack under load. Thanks.

shrp

They were <2 years old, but with the maintenance history during those years unknown they could have been little more than boat anchors when you got the cart.

Also, where was the cart (geographical location) during those years?

My cart came off a 3 year lease at a golf course outside Phoenix, AZ and the 18 month old batteries in it were the second set of T-105 batteries due to the hot dry climate (and possibly poor maintenance) and would only take a 85% SoC charge. I played with them some and eventually got them to charge to nearly 100% SoC and ran them for another year, getting over 20 miles range.

Are any of the high current cables getting the least bit warm? If so that is electrical energy being turned into heat rather than distance.

Same with the F/R switch. If it is getting hot, you are losing energy.