How can I test a xlr charging port

[Tracker]

I use a mobility scooter with two 24V AGM sealed lead acid batteries which I charge with a 24V 5amp SLA charger via XLR charging port. The batteries were not recharging and I discovered the 12 year old charger had died. Got a new charger and it was not charging either. Thought the new charger was defective, tried another new one, still not charging. I was told the batteries must be so low that the charger would not operate, and since the batteries were getting old, I had two new batteries installed, and they will not recharge. My research leads me to believe, since the batteries and charger are new and all connections to the batteries are intact with no signs of cable damage, that the XLR port probably needs to be replaced. No one locally will touch it, and the scooter is a 12 year old import from Israel, the replacement port and wiring harness being in limited supply and rather costly. I know how to remove and replace the port/wiring, but I really would like to determine if it is the problem before wasting the money. Is there a simple test with multi-meter I can do to see if it is bad? Thanks so much for your help.

 

[kellys_eye]

Measure the voltage at the battery terminals with/without the charger connected. You should see a change in voltage. Let us know what this is.

Similarly, disconnect the batteries and measure the voltage at the wires (charger on) and let us know the result too.

Your 'new' changer may have been damaged by the old batteries and, after replacing the batteries for good ones, not be doing as it should.

There are other tests you can do that involve measuring the charging current but we'll come to that if you get back to us with the results from the tests I mention above.

 

[Tracker]

Measure the voltage at the battery terminals with/without the charger connected. You should see a change in voltage. Let us know what this is.

Similarly, disconnect the batteries and measure the voltage at the wires (charger on) and let us know the result too.

Your 'new' changer may have been damaged by the old batteries and, after replacing the batteries for good ones, not be doing as it should.

There are other tests you can do that involve measuring the charging current but we'll come to that if you get back to us with the results from the tests I mention above.

Thank you for taking the time to reply. Here's my situation right now. The scooter has a 40 pound seat that has to be lifted off to get to the batteries underneath, and I'm temporarily incapacitated with an acute episode of severe back pain from spinal stenosis. Long story short, I will have to postpone getting back to those batteries to test further for a couple of days, perhaps. Meanwhile, I should tell you that I'm certain the old batteries were not, in fact, so low that the charger would not operate. Those old 50+ pound batteries are still here, and my multimeter measures them at 11.44 and 11.48V. The battery charger specs say if the combined voltage is 16V +/- 2V, then the charger will not operate. I think I was taken advantage of when I was sold new batteries. I've gotten two new chargers, and I don't believe the old batteries had damaged either one, nor that I've gotten two chargers in a row that are defective. If the port is bad, testing the battery voltage with the charger running would not indicate higher voltage.

I know that the scooter is wired so that when the xlr plug is connected, the scooter operation is inhibited, so you can't drive away with the charger connected. It occurred to me to test it. With the charger plugged into the port and turned on, I turn the key and operate the throttle, and the scooter moves. Wouldn't that suggest that the port is dead, since it is not communicating that the charger is connected? Perhaps I answered my own question: yes the port must be bad?

 

[Robert_fay]

Without a wiring diagram and some test I could not say for sure. I would lean towards either a switch int he port that has gone bad or a relay in your system that would disable to scooter/disable the charge port depending on if the switch is activated. if you can get to the port and there is a switch you should be able to check continuity on the switch when plugging in the charger. (not powered of course.
-Robert

 

[kellys_eye]

The interlock may well both disable the scooter movement AND activate the charging circuit so yes, the chances that there is an issue with it is high.

Can you tell whether the XLR activates a physical switch or do you know if there is a 'sense' pin in the plug that sends a voltage thru to the scooter that does the same thing?

A picture of the end of the plug and/or the wiring inside it may help to discover the answer.

 

[Tracker]

Measure the voltage at the battery terminals with/without the charger connected. You should see a change in voltage. Let us know what this is.

Similarly, disconnect the batteries and measure the voltage at the wires (charger on) and let us know the result too.

Your 'new' changer may have been damaged by the old batteries and, after replacing the batteries for good ones, not be doing as it should.

There are other tests you can do that involve measuring the charging current but we'll come to that if you get back to us with the results from the tests I mention above.

The Israeli manufacturer's technical manager suggested that the XLR port was the issue. After considerable delay, they located and shipped a new port/harness, which I installed, but the batteries still do not charge. I don't believe the charger is the issue, as I had installed new batteries, then got a new charger, which lights up but does not indicate charging (fan doesn't run, LED light stays green all the time, and the scooter battery gauge does not indicate the batteries have charged up fully.

I tested the battery voltages: with charger turned off the voltages are 12.36 and 12.32 individually; and 24.7 tested together. With the charger on, the voltages are exactly the same, with no increasing voltages. I have seen videos of charger tests indicating if the voltages do not increase with the charger on, then the charger must be bad. However, there is no direct connection from the XLR port wiring to the batteries, and the charger power goes through the circuit board(s) and other wiring It seems to me that lack of charging with the charger on does not prove the charger is bad. Couldn't the fault be with a circuit board or in other wiring between the charger/port and the batteries?

Note that there is a resettable fuse which I reset with no effect. Also, note that the scooter does run and functions perfectly other than the batteries not charging. Also, with the charger connected and on, the throttle moves the scooter, and there is an inhibiter which is supposed to prevent the scooter from running if attached to the charger, so apparently the scooter electronics can't "see" that there's a charger plugged in.

Can someone offer any other suggestions for how to proceed? Thank you very much.

 

[kellys_eye]

Couldn't the fault be with a circuit board or in other wiring between the charger/port and the batteries?

Absolutely!

You didn't indicate that this was in the circuit - we would have made this conclusion sooner.....

Can you post a picture of the board (clear, in focus, both sides)?

 

[Tracker]

Absolutely!

You didn't indicate that this was in the circuit - we would have made this conclusion sooner.....

Can you post a picture of the board (clear, in focus, both sides)?

I will be able to get back to this Sunday evening. Thanks.

 

[Tracker]

I will be able to get back to this Sunday evening. Thanks.

How can I check the voltage output with a multimeter of my 24V 5A charger with XLR plug? And what is the minimum output needed to recharge my bank of two 12V AGM batteries? Thanks.

 

[Tracker]

I will be able to get back to this Sunday evening. Thanks.

Photos attached. I can't get to the other sides of the circuit boards. The XLR port is pictured with the wiring harness, and the connections are secure (they only plug into their mates one way). The port is a standard 3-plug XLR. I don't see any kind of switch that is activated when the charger is plugged in. The circuit board with the XLR port is up front in the scooter's tiller. The other one is in a box in the rear, under the seat. There is a 15A fuse/circuit breaker in the rear box which I understand is a charging fuse. I have reset it and checked its continuity, and it is OK.

I found this on an old thread in electronicspoint.com addressing the issue of how the charger connection is detected so as to inhibit operation:

XLR Pin 1 = Battery positive.
XLR Pin 2 = Inhibits vehicle operation when pulled to battery negative.
XLR Pin 3 = Battery negative.

Pin 2 just lets the unit sense when the charger is connected, and disables
the drive, so you don't run away with the charger cord attached.

I can't personally vouch for the accuracy of this. But, since my scooter continued to operate with the new charger plugged in, I suspected the port was bad. But with the new XLR port installed, the scooter still runs with the charger plugged in.

I assume I need to find someone with expertise in checking the electronics to try to pinpoint the fault. Problem has been that no one around here wants to work on my imported machine.

 

[kellys_eye]

Sad that no one is prepared to even have a look at it.

Anyway, if there is a fault in the electronics then you're pretty much stuck (if no one will look at it) but in my experience it is the 'mechanical' parts that fail first and, in this case, the only mechanical part on that circuit board is the orange 'block' - a relay.

It is switching a relatively high current and this is detrimental to the contacts inside it and, over time, they corrode, stick etc causing typical faults as you're experiencing.

Reconnect everything and fix your test meter to the battery terminals then, using the handle of a screwdriver, give that orange box (relay) a few sharp taps and see if the meter reading changes. If you get lucky the charging process may start. If you're unlucky you'll read a few peaks in the reading. Either way, if you get any noticeable change then the relay needs to be changed.

If the fault is anything other than this relay then there's no way we can talk you through a repair - you'll have to find a local repair shop that will take the job on. You could ask them to simply change the relay and take the risk that this is the faulty part - it's a commonly available relay and easily swapped out so any competent wielder of a soldering iron will be able to do it.

 

[Tracker]

Sad that no one is prepared to even have a look at it.

Anyway, if there is a fault in the electronics then you're pretty much stuck (if no one will look at it) but in my experience it is the 'mechanical' parts that fail first and, in this case, the only mechanical part on that circuit board is the orange 'block' - a relay.

It is switching a relatively high current and this is detrimental to the contacts inside it and, over time, they corrode, stick etc causing typical faults as you're experiencing.

Reconnect everything and fix your test meter to the battery terminals then, using the handle of a screwdriver, give that orange box (relay) a few sharp taps and see if the meter reading changes. If you get lucky the charging process may start. If you're unlucky you'll read a few peaks in the reading. Either way, if you get any noticeable change then the relay needs to be changed.

If the fault is anything other than this relay then there's no way we can talk you through a repair - you'll have to find a local repair shop that will take the job on. You could ask them to simply change the relay and take the risk that this is the faulty part - it's a commonly available relay and easily swapped out so any competent wielder of a soldering iron will be able to do it.

I appreciate your advice and will try the relay trick. Actually there are two of those orange blocks, one on the front board and one on the rear board. Will experiment with both. Thank you. Will keep you posted if you wish.

 

[kellys_eye]

Will keep you posted if you wish.

It's always nice to know the result of advice - good or bad!

Good luck.

 

[Tracker]

It's always nice to know the result of advice - good or bad!

Good luck.

No joy so far! No voltage change or charging with tapping the relays. Waiting to hear again from tech in Israel. Thanks.

 

[Tracker]

Similarly, disconnect the batteries and measure the voltage at the wires (charger on) and let us know the result too.

What kind of multimeter readings should I expect to see at the disconnected battery cables with the 24V 5amp charger connected and powered up? Thanks.

 

[kellys_eye]

You presumably have a multi-stage charger therefore with the batteries disconnected it should default to around 24V.

 

[Tracker]

You presumably have a multi-stage charger therefore with the batteries disconnected it should default to around 24V.

Yes it’s a three stage charger. See attached image. Keeping in mind that my multimeter skills and experience are very limited, to basic measures of AC/DC voltage, continuity, etc., with it set to auto DCV and the probes contacting the battery cables (disconnected from the batteries), I get only wildly changing mV readings. So, as I understand it, not even 1V of juice is flowing through to the batteries.

I assume that means either the charger is defective or else something in the wiring or circuits through which the power travels to the battery cables is blocking the power. Can I use the multimeter to test the charger’s output? If my information is correct, the charger’s XLR plug pin 1 is positive and pin 3 negative (pin 2 telling the scooter the charger is attached). With the charger on, if I touch my test leads to pins 1 and 3 (or any other combination of the 3 pins for that matter), all I get is 0 or very low mV readings. Should I be seeing a reading of 24V? Or is this just not the way to check the charger’s output?

I’m just sort of at a loss here, so please excuse my inexperience. Thanks.

Bob

 

[kellys_eye]

What is the make/model of the scooter? They have all the wiring diagrams available on line (not sure about detailed schematics but something is better than nothing).

Can you show the charger itself?

 

[Tracker]

What is the make/model of the scooter? They have all the wiring diagrams available on line (not sure about detailed schematics but something is better than nothing).

Can you show the charger itself?

Do you mean to check the charger's output I have to test it at the circuit board? The scooter is the "Breeze" and came from Afikim Electric Vehicles (http://www.afiscooters.com/item/AfiScooter-s3). It is 12 years old but it appears to be the equivalent of what they sell now as model S3. They have the user's manual online but I've never found any wiring diagrams. And I can't be sure they haven't changed the circuit boards, wiring or other specs of the new models.

 

[Tracker]

What is the make/model of the scooter? They have all the wiring diagrams available on line (not sure about detailed schematics but something is better than nothing).

Can you show the charger itself?

Here's the charger. I got an email notification of a reply on the forum referencing an "attachment 38256" but when I click on it in the email I get an error--"you do not have permission to view this page..."--and I don't see that post on the forum itself so I haven't been able to view the attachment you asked me to check out. Thanks for sticking with me on this.