955E retired Hertz car rental shuttle

[checkoutmyjunk]

All I need to do at this point to get her OEM is a tire, some welding on the roof arms.

I wanted to get a feeling for how the 955 took the hills so I took the family out for a cruise around the neighborhood. With me + my wife kids and dog onboard I drove it on a two mile loop. I am 250lbs and the rest of them together might make another 250lbs. Coming from gas powered cart that tops 30 no problem, it took a bit of internalizing to accept the 10mph on flat paved roads and the 4-6mph climbing the steep grades we have here in the neighborhood. I already talked to the guy a plum quick and the 2awg cable and ends are sitting on my shelf.

I am on the fence about flipping the ole girl in the spring, it wasn't the slow speeds that killed it for me, it was the battery life. These are brand new off the shelf t-105s, there are 8 of them, thats over a grand in batteries and after a 2 mile crawl around my block I noticed the stock ezgo meter showing a bar above the middle point. The bar indicates a vague story about battery condition so I figured I'd let the pack cool down before firing up the charger.

After a few hours I fired up the lester App and sure enough it confirmed my batteries were at 54% and it took many hours to charge.

Brakes were all free, before and after the drive as verified on the lift. I did notice that one tire was flat upon return so I am sure that had a factor in the equation.

I do not like what this is indicating. Even if I could double it to 4 miles, thats pretty weak in my opinion. This unit is going to a place that has only dirt, while it's mostly flat, it's still dirt.
Am I jumping to conclusions? after the test run I checked the cables and connection points for heat. I did not check the motor or controller, would they cause a major drain on my batteries or am I expecting too much for a 1000 pound cart? I read somewhere that they 955E is pushing 1600lbs with the battery packs.

[ThreeCW]

My Cushman utility cart has 8 x 6v Trojan T-125's and has a 1620 lb base weight. My typical operating weight would be about 2000 lbs without a load.
All my driving is on gravel with hills or through pastures. I have never determined how many miles I can go (total range) but I'm estimating that I only see about a 15 to 20% depth of discharge with 2 or 3 mile of driving. My other cart specs are included at the bottom of this post.

Keep in mind that new batteries take a significant number of charges to develop their full capacity. See the attached T105 plot for more information. You can see on this plot that new batteries only have about 70% of their rated capacity and it takes about 100 charging cycles for them to develop 100% of their rated capacity.

You might want to check your actual pack voltage and then use the attached state of charge chart to double check your actual discharge. After a few hours, your voltage should have been stabilized.

Is your battery pack getting fully charged? Again, double check with the attached State of Charge chart and then compare that to the app.

As you suspect, bar battery meters are essentially useless. Best to install a good quality digital voltage gauge in its place to get a more accurate understanding of what your battery pack is doing.

[checkoutmyjunk]

Originally Posted by ThreeCW

My Cushman utility cart has 8 x 6v Trojan T-125's and has a 1620 lb base weight. My typical operating weight would be about 2000 lbs without a load.
All my driving is on gravel with hills or through pastures. I have never determined how many miles I can go (total range) but I'm estimating that I only see about a 15 to 20% depth of discharge with 2 or 3 mile of driving. My other cart specs are included at the bottom of this post.

Keep in mind that new batteries take a significant number of charges to develop their full capacity. See the attached T105 plot for more information. You can see on this plot that new batteries only have about 70% of their rated capacity and it takes about 100 charging cycles for them to develop 100% of their rated capacity.

You might want to check your actual pack voltage and then use the attached state of charge chart to double check your actual discharge. After a few hours, your voltage should have been stabilized.

Is your battery pack getting fully charged? Again, double check with the attached State of Charge chart and then compare that to the app.

As you suspect, bar battery meters are essentially useless. Best to install a good quality digital voltage gauge in its place to get a more accurate understanding of what your battery pack is doing.

Wow!. I really appreciate how carefully you read my questions and how completely you addressed them with supporting documents!

I would like to install a voltage meter as well as a temperature strip for the motor casing if I keep this cart.

Next time I get out to the garage I will look at the voltages and see where they fall on the chart. I called Bill at Lester Electrical and verified that I am using the correct battery profile. The Summit II is brand new and I did verify the batteries are topped off.

For the 12v circuit, the negative was already at there so I just jumped a lead from two batteries over to power the fuse panel. Does puling 12v from just two cells present another issue lower the voltage on two batteries and ultimately the entire pack?

[ThreeCW]

Originally Posted by checkoutmyjunk

Does puling 12v from just two cells present another issue lower the voltage on two batteries and ultimately the entire pack?

The preferred method to connect 12 volt accessories is to install a 48 to 12 volt convertor ... that way the 12 volt accessories drain all the batteries in the pack equally. Drawing down two batteries of the pack excessively can lead to undercharging the drawn down batteries, overcharging the stronger batteries and can lead to a shorted battery pack life.

If there is very little 12 volt use (no headlights or stereo use for example), then pulling from 2 batteries may be acceptable.

48 to 12 volt convertors are relatively inexpensive (especially compared to batteries).

Have a look for reducers here from a site sponsor: https://www.cartsunlimited.net/12v-reducers.html

[Kingstir]

Very cool project- good luck with it.

[checkoutmyjunk]

Originally Posted by ThreeCW

The preferred method to connect 12 volt accessories is to install a 48 to 12 volt convertor ... that way the 12 volt accessories drain all the batteries in the pack equally. Drawing down two batteries of the pack excessively can lead to undercharging the drawn down batteries, overcharging the stronger batteries and can lead to a shorted battery pack life.

If there is very little 12 volt use (no headlights or stereo use for example), then pulling from 2 batteries may be acceptable.

48 to 12 volt convertors are relatively inexpensive (especially compared to batteries).

Have a look for reducers here from a site sponsor: https://www.cartsunlimited.net/12v-reducers.html

Thank you ThreeCW, I did run it through at least 3 charge cycles since I posted and changed a few variables. I took voltages and noticed after the 2nd charge cycle that I measured a few fliers, 7.1v on one cell. After checking my meter with a d cell battery I realized that after 5 tries I got 4 different voltages. I have been relying on the app built into the charger, when I connect to the app , it states 100% charge. It's only after I plug it in to AC power does the charger give me a reading, by the time it displays on my phone, the voltage from the charge cycle has already ramped up.

There has to be reason this cart is only seeing a couple of miles before getting close to 50% state of charge. During my rides around the paved neighborhood, I tried to simulated the same distances but change the weight in the cart and the steepness of the hills. After cycling through a few variations of these factors I was able to see between 40 and 25% state of discharge and that is an improvement but, not enough for me to feel great about getting a days use out of the cart in my intended application.

One of the tests I covered similar distance, but I added about 800 lbs of human and hilly terrain in stones and grass and only netted a 38% state of discharge.

I am eager to get a new fluke and document the voltages to see what I can learn. I would love to throw in a plumb quick Black Window with and decent controller. I have a big roll of 2awg, a hydraulic crimper. I worked for Kilovac for years and could likely get a "sample" of a LEV200 or a zonka, putting in a reversing contactor would only be a few more bucks. I can't commit yet if the battery life I am seeing is normal then I can only expect more power consumption and even shorter range.

I am at a point in the project that I should consider what I have into the cart and what it's worth if it can't serve my needs

[checkoutmyjunk]

Originally Posted by Kingstir

Very cool project- good luck with it.

Thanks, I think its a cool thing to spend a few hours of my spare time on.

[ThreeCW]

Originally Posted by checkoutmyjunk

After checking my meter with a d cell battery I realized that after 5 tries I got 4 different voltages.
I am eager to get a new fluke and document the voltages to see what I can learn.

Did you change the battery inside your meter? This is a very common problem with multi-meters. A fresh battery in your meter should result in accurate and repeatable readings. If you readings are still wonky with a fresh battery and the leads check out, then maybe it is time for a new meter.

Originally Posted by checkoutmyjunk

I have been relying on the app built into the charger, when I connect to the app , it states 100% charge. It's only after I plug it in to AC power does the charger give me a reading, by the time it displays on my phone, the voltage from the charge cycle has already ramped up.

I would suggest basing your state of charge voltages on an actual meter reading and ignoring the app for now. Make sure the you allow enough time for your voltage to become stable after charging (12 to 24 hours) or after use (1 hr). Voltage is stable if you get 3 identical voltage readings taken 10 minutes apart. If the voltage is still changing, allow more time for stabilization. Once the voltage is stabilized, then compare to the State of Charge Chart. You don't really need a Fluke to get a good voltage reading ... an under $50 meter should give you an accurate voltage reading as well. I happen to have 2 older Fluke meters (Fluke 29 and Fluke 79) and my $20 Gardner Bender Multimeter gives me the same reading as my Flukes (within an acceptable error band anyway). Fresh batteries in the meter can make a a big difference

[checkoutmyjunk]

I took the 955 out for a spin tonight. Guessing 2 miles, under 3 total on this charge. The cart was loaded with 3 adults and two small kids in the hills around my house. After resting for at least an hour I measured 50.9v and 6.3 for each battery.

I'm going to take it out again later for another two miles and see what my voltage is. I think the long hills are the biggest factor. Maybe letting the motor cool is important. This result is encouraging. I have a 400a reversing contactor on the way and plan to start building my 2 awg cables tonight. I doubt the cable upgrade will have measurable improvement in the way I am conducting my "tests"

Im also curious what the app on my charger tells me after my night ride.

While I don't think the electric carts are best suited for my use, I like how silently it creeps through my quiet neighborhood.

[checkoutmyjunk]

2 days later I measured the voltage in the morning and was seeing 51v

That evening I took my two boys out for a 2 mile rip on our longest most steep hills in the neighborhood. I let the cart rest for a 2 hours and measured 50.4v. At about 12am I plugged the charger in, the Summit app showed 58% state of charge.

I am not sure when the charge cycle completed but at 6pm about 18 hours later I am reading 51.4v