EZGO PDS Issues after Alltrax48400PDS install

[fishwithcarrs]

Gents First time post'r but long time reader,
BL I have a EZGO PDS cart, 23 inch tires, that we upgraded with the Alltrax XCT400PDS controller, 2G cables, and updated solenoid. No issues prior to the upgrade just wanting a little more performance going up and down hills in the neighborhood with the backseat full of kiddos. Been about 3 months since the upgrade and we have enjoyed the better performace but started having periodic issues with the cart shuddering on start, but normally just a recylcle of the F/R switch and we are back off and running. Well this problem has been getting worse (as most of them do when you ignore them and hope they go away) and the other day we got stranded at the community pool. After doing some trouble shooting with the Alltrax controller it showed a "low battery fault" (1 green followed by 2 red). I checked the batteries, and they showed 37.5v (6.25,6.24,6.24,6.23,6.23,6.25) and 36.7 with the peddle down with no go. After I got it running I saw the volts went down to 28.3 (the controller low voltage was set at 28 ) with each batt at 5.1,5.0,4.8,4.0,4.5,4.9. going up big hills. The kicker is the performance is still pretty good, when it does want to go, and gets us where we need to go.
So all that said, besides a new set of batteries (saving up for the 48 volt upgrade next year), how does one keep this cart running in the mean time? Is there another issue I should be looking at? A setting you can adjust on the Alltrax controller that lower the threshold for the low battery fault?

[yamahaguy97]

hmm its hard to tell

Honestly until you change your batteries, the problem is not going to go away. dropping to 36v when you press the pedal is too low. when your batteries are done charging the pack should read 40v or a little more. I'm just surprised considering the drop of the batteries you are still able to drive it around

[beach cart]

Dead batts. It sucks but change the pak, you'll be happy again. The shutter is a sign. If your not convinced, have a cart shop load test.

Sent from my SM-T710 using Tapatalk

[yamahaguy97]

Originally Posted by beach cart

Dead batts. It sucks but change the pak, you'll be happy again. The shutter is a sign. If your not convinced, have a cart shop load test.

Sent from my SM-T710 using Tapatalk

good point, never rely on your volt meter to determine if a battery is good or not, because a bad battery can still read over 6 volts until you put the 100+ amps of load test on it I have to explain that to countless customers

[cgtech]

Your current batteries are horrible. Until some good batteries are in there, you are chasing ghosts (but you know the ghost's name, "batteries").

[scottyb]

Something else to think about. The shudder. What is it exactly? What happens mechanically when the cart shudders instead of doing what you told it to do?

The solenoid is rapidly engaging and disengaging causing the power supply to be turned on/off & on/off rapidly and repeatedly. Why?

Battery voltage is highest when at rest and lowest when under load. At rest the battery voltage is high enough to activate the solenoid coil and the cart begins to go but the pack cannot sustain the power needed run the cart and the pack voltage is significantly reduced by the load. This reduced voltage is not high enough to keep the solenoid closed so it opens, stopping the cart.

BUT WAIT> as soon as the solenoid is opened the load is removed from the pack & the voltage rises and the solenoid re-engages only to pull the pack down to where it has to drop out again. And this continues to happen over and over at a very high rate of speed. You feel the cart shudder..... the solenoid is being hammered. Contact wear & damage is occurring at a accelerated pace when this happens.

[fishwithcarrs]

Gents, copy all, makes sense, probably should have invested in a new battery pack instead of the upgrade, but hindsight is 2020. Will do the right thing and keep it parked until we can get a new battery pack.

So makes me think that an upgrade to 48 volts may not be required if we were pretty happy with the performance crappy set of 36 volts batteries. We could swing that a lot sooner. Anyone have experience with that? Again our goal is a people neighborhood people mover, going up and down hills with two adults 4 kids.

And a side note would this upgrade have had anything to do with running down these batteries faster? The wife is not impressed with my results, and is reluctant to let me pour more money into this thing, without a solid gameplan.

[hunt365]

Seeing as you need new batteries anyhow, you could go with six 8 volt batteries. You'll need a 48 volt charger and a few longer cables. Two adults and four kids is quite a load on a cart and the increased voltage should help.
The age and maintenance history of your battery pack probably has more to do with them failing than the upgrade. Any battery pack is gonna run down quicker as it draws more amps. The key is to keep them charged after every use and don't discharge them too much. Also check the water regularly.

[cgtech]

Originally Posted by fishwithcarrs

And a side note would this upgrade have had anything to do with running down these batteries faster?

Yes, I have seen it happen several times doing upgrades on 4x 12v Yamahas. I tell the customer "we need to just do these old batteries while we are upgrading". Customer says No, comes back in about a month saying "my cart looses power quick, and my range is terrible, what's wrong with my new controller, I'm sure it's not my batteries, I just did those 4 years ago". LOLOLOL!

[fishwithcarrs]

Ok, Gents went out and got brand new trojan 105s, and initially it worked great, very impressed with the better performance, but after two quick trips it started shuddering on start up again (same day). I looked up the error code on the controller was a "precharge failure", the definition in the alltrax manual states "B+ voltage and KSO voltage differ by more than 5v. Stuck solenoid".

So assuming these batteries are not the issue, where do we go from here?