Opinions on battery life

[ThreeCW]

Originally Posted by Bama Brad

Get the roypow for $2,200 that should last 15 years.

Does anyone have experience with any of the lithium batteries in heavy duty, suck the guts out of your pack conditions? I expect that Noonan's cart could be sucking 300 to 400 amps when pulling hard (based on what I see with my heavy Cushman cart).

It does not take much to get the amps up on a heavy cart.

[Bama Brad]

Sergio will be the expert here, but I would think that Lithium would be as good (if not better) as FLA's for this application.

[Sergio]

The OP mentioned that changing battery chemistry would not be his call and given the number of carts they maintain likely not a viable option.

If You look at the graph I posted for the T-105 and given that the cart must be charged at the end of the day because it barely made... I would say they got all the life out of those batteries in 2 years.

If they only used 20% SOC at the time it would last 3,000 charge cycles.

[Noonan]

90% of the rest of the fleet consists of Precedent and DS carts that the maintenence guys just traverse the property with, in small areas. They have single tool boxes and don't do any towing.
The terrain is all paved cart paths that are for the most part flat. The only time I see "hills" are when I go to the island to facility operations or to my office and I climb the ramps to the 2nd level of the parking garage, but for the most part I have all but removed that from my travels by parking at ground level and using stairs about 95% of the time.
The team I am on consists of 4 of us who have XRTs but mine pretty much does all the towing, mostly utility trailers with various loads of a couple hundred pounds plus the weight of the trailers which are just small 5x8 Lowes specials.
I'll get my multimeter out in the A.M. and get some readings on the individual batteries and the pack.
We only get deliveries of batteries every Wednesday, so I'll have to wait a week before I get a new set.
I did manage to score a Summit 2 charger that I am going to mount in the cart and hardwire to the pack so I can use the app to better monitor the charging from here on out.
I should have some time tomorrow to get it installed and set up before the new pack goes in.
Once it does, would it be best to install them closer to the end of the day so they can go on the charger before they get any heavy use?
These things spend every day of their life in the Florida heat so I try whatever I can to get everything out of them.

[ThreeCW]

Originally Posted by Noonan

Once it does, would it be best to install them closer to the end of the day so they can go on the charger before they get any heavy use? These things spend every day of their life in the Florida heat so I try whatever I can to get everything out of them.

It would be great to get a full charge on your new battery pack before using it ... so installing it later in the day would be best.

With an onboard Summit 2 charger, you might want to take advantage of "opportunity charging" when ever you can though out the day so you can limit the depth of discharge on your battery pack. If you are parked on a job for an hour and you can plug your cart in, it would help you extend your pack life. If you are taking a lunch break and can plug your cart in, take that opportunity too. This is in addition to your regular overnight charging.

Keep in mind that your new battery pack will not be at its full capacity until your get 100 charges or so and it gets "broken in". See the attached plot for Trojan T-105 batteries which shows capacity vs. number of charge cycles. According to this chart, your batteries will only be at about 70% of their rated capacity when they are new compared to when they get broken in. Another reason to follow "opportunity charging" practices.

[Noonan]

I took some readings this first thing this morning .
It was put on the charger yesterday at 3pm so I'm guessing it shut off sometime around midnight?
I got the following readings on each battery with my multimeter:
6.4 6.5
6.5 6.3
6.4 6.5
6.3 6.4
and 51.2 on the pack reading.
On my way to my shop the digital meter I have on my dash read mid 45 volt range while driving with a few dips to high 44 when starting from a stop.

[ThreeCW]

My Trojan T125 pack takes a full 24 hours to get a stable voltage reading ... and the pack stabilizes at somewhat higher than the charts at 52.1 volts or so.

It looks like you have a few weaker batteries in the pack at 6.3 volts each ... 90% state of charge based on the chart.

It would be interesting to see what your static voltages are on a Monday morning, after the batteries have the weekend to stabilize (assuming the charger does not kick back in).

It looks like you may be a good example of someone who looks after their batteries but yet still wears them out after 2 years due to heavy duty use.

[Noonan]

Unfortunately, except for the weekends, it doesn't get 24 hours to sit, but I will take a reading on Monday as well. I got the Summit 2 installed today and wired directly to the pack. I set the battery profile for Trojan 105's and set it to balance charge before I left. I'll see if any of my readings have changed in the A.M.

[Tom47]

Sorry about reading this as an EZ Go cart. I need to read slower, but others may tell you that happens to me quite a lot around here!

As ThreeCW said, I am certain the batteries will need to be replaced in the cart based on your trailer usage.

I bought my cart in Jan. 2016. It had Jan. 2013, 8 volt, Crown batteries so I was sure I would need to replace them soon. Here I am 5 years later with the same batteries. The SOC on the last (Neg.) pack battery shows only 90 % after a full night charge. Specific gravity is around the redline at 1.21 on three cells. But the pack voltage after charge is 51.8 to 52.2.

We can go on our extended rides, 12 to 20 miles on flat roads at all speeds and I usually see 60 to 70% SOC when I get back to the barn.

However, a week ago I pulled my 46" lawn sweeper around the yard for maybe 10 minutes. I stopped when I saw 48.4 volts on the dash meter at rest. That is lower than I've ever seen it at rest, 50% SOC, dangerously low. I charged it over night, had 52.0 the next morning. I let it sit for a full day off the charger. The next morning it showed 51.2. Subsequent long rides have been the same as earlier ones. I probably shortened any remaining battery life by pulling the sweeper.

So pulling any kind of trailer can really shorten battery life.

[Bama Brad]

Yea, the job you are having to do with this cart may be better served with a gas cart. (when bossman gets off his wallet.)