Battery, charger, or tire issue?

[EzIndyGo]

Originally Posted by Mooncarter

Those tires look HUGE to me.

Because they are! Too big!

Jonnie B - Interesting... I took a handheld multi meter and put it on the pack. The readout is 38.2-38.3 while the digital gage from Carts Unlimited is reading 37.2-37.3. Do I have a faulty digital gage maybe?

I'll PM Scottie B to look here.

Edit: After a few minutes on the charger, the multimeter and digital meter bags to sync up and read similar voltages. Im so confused.

[JohnnieB]

Originally Posted by EzIndyGo

Because they are! Too big!

Jonnie B - Interesting... I took a handheld multi meter and put it on the pack. The readout is 38.2-38.3 while the digital gage from Carts Unlimited is reading 37.2-37.3. Do I have a faulty digital gage maybe?

I'll PM Scottie B to look here.

Edit: After a few minutes on the charger, the multimeter and digital meter bags to sync up and read similar voltages. Im so confused.

Are both of the dash mounted DVM's leads connected directly to the battery pack's main negative and main positive terminals, or is the positive lead routed through one or more sets of switch contacts?

If the leads from the dash mounted DVM and handheld DVM are not looking at exactly the same electrical points, there can be a difference in the respective voltage readings due to differences in the amp flow in the electrically different underlying circuits.

[EzIndyGo]

Originally Posted by JohnnieB

Are both of the dash mounted DVM's leads connected directly to the battery pack's main negative and main positive terminals, or is the positive lead routed through one or more sets of switch contacts?

If the leads from the dash mounted DVM and handheld DVM are not looking at exactly the same electrical points, there can be a difference in the respective voltage readings due to differences in the amp flow in the electrically different underlying circuits.

The leads are on the main leads. I'm taking the handheld DVM readings on the same terminals.

I'm using 16G wire. Surely thats not causing that much of a drop.

[JohnnieB]

Originally Posted by EzIndyGo

The leads are on the main leads. I'm taking the handheld DVM readings on the same terminals.

I'm using 16G wire. Surely thats not causing that much of a drop.

If the leads of both the dash mounted DVM and handheld DVM are connected to the battery pack's main terminals, both meter ought to read pretty close to the same (+/- 0.5V or so) unless the voltage being measured is something other than straight-line DC.

The charger puts out DC with a 120hz ripple on it and the amplitude of that ripple will vary with the amount of amps being put out, which varies inversely with on-charge voltage. In other words, the closer the on-charge voltage gets to the charger's cut-off voltage, the less ripple is riding on the DC.

I suspect the dash meter and the handheld are reacting differently to the ripple on the charger voltage.

FWIW: I've got 4 handheld DVMs varying in quality from throwaways to bench grade and a dash mounted DVM connected directly to my cart's battery pack that has been on nearly continuously for 9 years. They all read a bit different when the batteries are on float charge and pretty much the same (+/- 0.2V) when charger is disconnected. Never checked when charger was putting out a lot of amps.

[EzIndyGo]

Well, end of the day. My pack is not holding 38.2V after charging. I've performed several continuity checks in the charger (AC in, diodes, amp fuse) laid out on a YouTube video and it seems to check out. I think it is kicking off around 45V. The next morning, it will show 37.5V.

It seems as though the DVM has fallen in line with my handheld multimeter.

I just wonder if these 2017 batteries were not cared well enough for and they're fading already. It took nearly a full gallon of water to get to the fill neck.

[JohnnieB]

Originally Posted by EzIndyGo

Well, end of the day. My pack is not holding 38.2V after charging. I've performed several continuity checks in the charger (AC in, diodes, amp fuse) laid out on a YouTube video and it seems to check out. I think it is kicking off around 45V. The next morning, it will show 37.5V.

It seems as though the DVM has fallen in line with my handheld multimeter.

I just wonder if these 2017 batteries were not cared well enough for and they're fading already. It took nearly a full gallon of water to get to the fill neck.

The PW-28115 charger typically shuts off in the 44V to 46V range, so that is normal.

An At-Rest voltage of 37.5V means the batteries are only about charging to about 80% SoC.

Fluid height is typically about 1/4" below the bottom of the fill neck. (See attached drawing)
Adding a gallon of water (Hopefully distilled water) sounds like a lot, but typical 6V battery hold about 7 qts of electrolyte, so a 36V battery pack holds about 42 qts, or 10.5 gallons, and 1 gallon is only 10%.

---------------
Try some back-to-back charging. IE: Charge overnight as usual, but start a new charge the next morning and again at noon and again the next night.

In other words recharge the batteries two or three or four times a day whether cart is used or not.

The 18 month old batteries that came with my cart would only charge to 85% and by repeated back-to-back charging I got them up to 95% ib a month or so and got another year out of them.

[EzIndyGo]

Originally Posted by JohnnieB

The PW-28115 charger typically shuts off in the 44V to 46V range, so that is normal.

An At-Rest voltage of 37.5V means the batteries are only about charging to about 80% SoC.

Fluid height is typically about 1/4" below the bottom of the fill neck. (See attached drawing)
Adding a gallon of water (Hopefully distilled water) sounds like a lot, but typical 6V battery hold about 7 qts of electrolyte, so a 36V battery pack holds about 42 qts, or 10.5 gallons, and 1 gallon is only 10%.

---------------
Try some back-to-back charging. IE: Charge overnight as usual, but start a new charge the next morning and again at noon and again the next night.

In other words recharge the batteries two or three or four times a day whether cart is used or not.

The 18 month old batteries that came with my cart would only charge to 85% and by repeated back-to-back charging I got them up to 95% ib a month or so and got another year out of them.

Thank you for the tips. Apparently the source i used on water level was wrong, as it instructed to fill to the bottom and not leave a quarter inch. Should I attempt to pull some water out? Yes, I used distilled.

I saw somewhere else here where you guggested the repeated charge cycles. I began doing that yesterday. I will continue to do so.

I have a bad feeling that I'm going to continue to fight battery issues with the 23" tires without doing one of two things. Upgrade the controller and supporting components or reduce tire size. I suspect I'm going to have a hard time convincing the wife to drop the money in a controller, so I may keep my eyes out for 20" tires. I dont NEED the 23", but they are nice to have in our woods. End of the day, I still have the lift for some clearance and may be ok losing the 3" of diameter off the tire. Just won't look as filled out.

What's the validity of upgrading to lithium drop in (Allied for example) units when I can't squeeze anymore life out of these Duracells? My assumption is that I will reduce the overall life expectancy of them as well?

[JohnnieB]

Originally Posted by EzIndyGo

Thank you for the tips.
1. Apparently the source i used on water level was wrong, as it instructed to fill to the bottom and not leave a quarter inch.

2. Should I attempt to pull some water out? Yes, I used distilled.

3. I saw somewhere else here where you guggested the repeated charge cycles. I began doing that yesterday. I will continue to do so.

4. I have a bad feeling that I'm going to continue to fight battery issues with the 23" tires without doing one of two things. Upgrade the controller and supporting components or reduce tire size. I suspect I'm going to have a hard time convincing the wife to drop the money in a controller, so I may keep my eyes out for 20" tires. I dont NEED the 23", but they are nice to have in our woods.

5. End of the day, I still have the lift for some clearance and may be ok losing the 3" of diameter off the tire. Just won't look as filled out.

6. What's the validity of upgrading to lithium drop in (Allied for example) units when I can't squeeze anymore life out of these Duracells? My assumption is that I will reduce the overall life expectancy of them as well?

1. The best thing to do is find & follow the specs from the battery manufacturer, but Duracell doesn't actually make the golf cart batteries they sell, they relabel batteries made by others. The OEM might be listed on the labeling someplace. If not go with the generic level I posted.

2. Once the distilled water is added to the battery, it is no longer water, it is a part of a solution of water and sulfuric acid known as the electrolyte. If the electrolyte bubbles out while charging, leaving puddles on the battery tops, the batteries are overfilled and a few ounces of the electrolyte should be removed. It is a 30% concentration of sulfuric acid, so be careful with it and store it safely to add back to the batteries as needed. Once it has been used up, go back to filling with distilled water. (Only water is used in the charge/discharge process, there is no sulfuric acid loss due to electrolysis or evaporation, only spillage or overflow.)

3.

4. Good luck.

5. No matter how much you lift the frame and body off the axles, the ground clearance at the lowest point (differential pan) is determined by the radius of the tires. With stock height (18") tires, the bottom of the differential clears the ground by 4.5", which increases 0.5" for each inch the tire height is above 18".

6. Going to Lithium is far more than an aftermarket controller and tires combined.

[EzIndyGo]

Originally Posted by JohnnieB

1. The best thing to do is find & follow the specs from the battery manufacturer, but Duracell doesn't actually make the golf cart batteries they sell, they relabel batteries made by others. The OEM might be listed on the labeling someplace. If not go with the generic level I posted.

2. Once the distilled water is added to the battery, it is no longer water, it is a part of a solution of water and sulfuric acid known as the electrolyte. If the electrolyte bubbles out while charging, leaving puddles on the battery tops, the batteries are overfilled and a few ounces of the electrolyte should be removed. It is a 30% concentration of sulfuric acid, so be careful with it and store it safely to add back to the batteries as needed. Once it has been used up, go back to filling with distilled water. (Only water is used in the charge/discharge process, there is no sulfuric acid loss due to electrolysis or evaporation, only spillage or overflow.)

3.

4. Good luck.

5. No matter how much you lift the frame and body off the axles, the ground clearance at the lowest point (differential pan) is determined by the radius of the tires. With stock height (18") tires, the bottom of the differential clears the ground by 4.5", which increases 0.5" for each inch the tire height is above 18".

6. Going to Lithium is far more than an aftermarket controller and tires combined.

1-4. Thanks.

5. Very true.

6. The lithium comment was specifically around the fact that I'll eventually need new batteries. Either if that's now or if I can squeeze another X years out of what I have now. This is all separate from any other changes.

I like the Pro's associated with Lithium, regardless of the up-front cost. If I can feel confident to get at least 3X life out of Lithium, I'd like to go that route. However, my current setup tells me that I'll reduce the life of Lithium as well, although it still may be several times better than Lead-Acid. That is, unless, the Lithium delivers power differently and won't be as negatively affected by the draw of the bigger tires.

[JohnnieB]

Originally Posted by EzIndyGo

6. The lithium comment was specifically around the fact that I'll eventually need new batteries. Either if that's now or if I can squeeze another X years out of what I have now. This is all separate from any other changes.

I like the Pro's associated with Lithium, regardless of the up-front cost. If I can feel confident to get at least 3X life out of Lithium, I'd like to go that route. However, my current setup tells me that I'll reduce the life of Lithium as well, although it still may be several times better than Lead-Acid. That is, unless, the Lithium delivers power differently and won't be as negatively affected by the draw of the bigger tires.

The idiosyncrasies of lithium batteries aren't in my realm of expertise, but I don't think they react to heavy loading the same as lead-acid batteries. Suggest asking over in EZGO lithium, or the generic lithium areas of BGW.