Battery drainage after modifying accelerator pedal/rotary position sensor???

[kabinski]

2019 2Five with 2,000 miles / Trojan batteries from when new

When I bought the cart new, in order for it to reach it's max speed of 25mph, I had to press extra hard on the accelerator pedal. Pushing the pedal with a normal force, it ran 24mph. Last week, I removed the accelerator pedal assembly and used a Dremel to file off a bit of metal where the accelerator pedal arm made contact with part of the assembly framework. This allowed the pedal an extra 1/4"-1/2" of travel (measured from the top/end of the pedal). This extra travel now allows the rotary position sensor to rotate farther, which in turn enables the cart to reach its max speed without having to press hard. Once max speed is reached, there is still approximately 1/4" of travel before the accelerator pedal comes to a stop.

My batteries are now draining quicker than before. Not drastically, but noticeably. On an 8-mile trip earlier this evening, the gauge dropped 2 or 3 bars from full charge. Before (last year/season), it would drop 1 (maybe 2) bars for the same distance traveled. It very well could be because of battery age. I did have to add water to a couple plates in the batteries for the first time this past summer/fall. I had to add water to one plate this past week. The cart was only operated a few times throughout winter (garaged) here in SC.

I guess my 2 main questions are:

1) engaging the rotary position sensor more than it needs to be (rotating beyond the point needed to achieve max speed) due to the now increased pedal travel, would this somehow draw more current, and thus deplete the batteries quicker? For example, I drive the cart now just as I had before, with the accelerator pedal pressed all the way down most of the time to stay up with local traffic. For what it's worth, the sensor has plenty of available rotation left once the pedal travel stops. I realized this after removing it from the pedal assembly. I test drove with a screwdriver inserted into the groove of the sensor and accelerated by turning the screwdriver. It was able to rotate much farther than the pedal assembly allows. However, even with the sensor rotated fully clockwise, the cart still maxed out at 25mph. If I had to guess, max speed was reached at approximately 3/4 of full turn of the sensor. Again, just wondering if rotating that sensor a little farther than needed would result in greater battery drainage. My logic says no, but I'd love to hear from the experts out there.

2) would traveling at an almost constant 25mph (as compared to 24mph) make that much of a difference in battery drainage? I know it will drain quicker, but would it be that noticeable?

I'm thinking my batteries are starting to drain more quickly due to age. I just want to make sure my pedal travel mod wasn't a no-no. Thanks for any input.

[ojo]

Fighting for every single mph, i know that But a little more travel of the accelerator shouldn't make a great difference. 2 years old Trojans are best ager, maybe different in the climate conditions of SC. And 1 mph more or less top speed can't drain the batteries significant also. Sorry, not much helpful, but I'm sure, some others will follow...
And, always be careful dealing with the electrical components of that cart, they're sensitive and each mistake can end up in a financial desaster.

[kernal]

My experience with living with these things for 20+ years now is to advise caution about making to much of this. Don't overthink it.

The battery capacity (range per charge) will vary a lot as a result of many factors, one of which is temperature. FLA batteries are rated at 80°F. According to Trojan, battery capacity is about 15-20% less at 60° all else being equal. My batteries in 2 carts are just know starting to perform range wise like they should compared to over the winter. I'm in similar climate (Atlanta) and the carts are garaged also.

The battery gages on golf carts are a guide only. They are not accurate and should be regarded with skepticism. They should be verified by another method periodically. I use a hand held digital multimeter. There are many threads about this on the forum if you care to pursue it.

I advise to press on and enjoy the cart as the weather improves but keep one eye open to the possibility of batteries starting to age especially if they are 12v ones. On average, 2 years is past the half way mark for the 12v batteries in this climate.

[kgsc]

Top speed of the cart is probably being limited by the controller and not the throttle sensor so the throttle mod helped but the real fix is tweaking the controller parameters to get you more.

[meimk]

The low water, the long periods sitting over the winter has probably allowed the batteries to sulfate a bit more than they normally have before. Give it a few back-to-back charge cycles to see if you can regain the bit of capacity you seem to have lost. As kernal mentioned those digital bar graph meters are none too exact. Use a digital volt meter to see where you really are.
Keep in mind that as the batteries age they WILL lose some of their capacity. The trick is to try what you can to keep a much as you can for as long as you can.

[kabinski]

Thanks for the feedback and tips, y'all . After reading up on another post here the other day, I also just started placing my cart on the charger after each use. Years ago, I was told by someone it was best to run them down about halfway before charging. I got about 5 solid years out of a set of Trojans that way, and we use our cart to go just about everywhere here in the spring, summer and fall. Placing it on the charger after each use seems to be the consensus here, so we'll go that route from here on out. Thanks again.

[JohnnieB]

Something not yet mentioned is the colder the battery is, the less storage capacity is has, so if you are comparing the performance last summer with the performance this spring, there will be less performance. Plus any storage capacity losses due to aging.

Storage capacity is rated at 80°F and decreases by about 9.4% for every 15°F below that. (Isn't linear, but averages 0.625% per 1°F)

[kabinski]

Originally Posted by JohnnieB

Something not yet mentioned is the colder the battery is, the less storage capacity is has, so if you are comparing the performance last summer with the performance this spring, there will be less performance. Plus any storage capacity losses due to aging.

Storage capacity is rated at 80°F and decreases by about 9.4% for every 15°F below that. (Isn't linear, but averages 0.625% per 1°F)

Thanks, JohnnieB. Learning a lot from you lately. I did notice a little improvement with warmer weather today.