Sapphire 2 mobility scooter failure, any pointers please?

[ericmark]

Went to doctors on it mainly to test it before my wife uses it, just fitted two new 35 Ah batteries, and it failed on the return leg, and had to push it home.

The volt meter went to zero, and the brake engaged with a bang, which it would with power failure, tried the 40 amp circuit breaker and no luck, since nothing seems to have power, would suspect either that or one of the two 125 amp fuses.

There is also a 3 amp fuse and a 8 amp fuse I think the latter only to do with charging, I was whacked on return 67 kg and can't fully disengage the drive, so hard pushing, so going to start in the morning.

First will be the battery pack, but any pointers as to possible failure, it is some 16 years old now, although not used that much, still on original tyres, it has been parked up for some 3 to 4 years with faulty battery, new fitted around June, but this is first real trip with new batteries.

 

[securespark]

I'm sorry Eric, I can't help.

But I wanted to chip in and say that I have wanted tech stuff regarding my TGA scooter, but there is next to nothing out there.

With all the thousands of mobility scooters out there, you think there'd be a fair few videos on YT regarding maintenance, but no.

 

[ericmark]

I have a PDF giving a far bit, but seems it needs some hand held programmer to do a lot with it. It was going up a fair hill just before it went, and I am a little over weight. Anyway meter out in the morning and see what I can find.

 

[securespark]

I am overweight too, but my scooter is rated for well over my weight,

Need to check your scooter's weight limit.

Although if the reason your scooter died was because it wasn't rated to carry your weight, I would have thought that a thermal cut-out in the motor would have tripped.

 

[ericmark]

About to go down and have a look, the 40 amp cut out does not seem square in casing, so crossing fingers it's that.

 

[ericmark]

The darn thing works again, stripped to carry in flat, comes in 5 parts, rebuilt after opening main battery case to check overload fuses an battery, both 12.4 volt, rebuilt and all works, so not a clue why it stopped. Could be poor connection on one of the multi-connectors, or some thing resetting, but nothing in the instructions to say there is anything with auto resets.

 

[JohnW2]

The darn thing works again, stripped to carry in flat, comes in 5 parts, rebuilt after opening main battery case to check overload fuses an battery, both 12.4 volt, rebuilt and all works, so not a clue why it stopped. Could be poor connection on one of the multi-connectors, or some thing resetting, but nothing in the instructions to say there is anything with auto resets.

Is there some sort of thermal cut-out which may have operated (correctly or otherwise)?

Kind Regards, John

 

[ericmark]

Not on the main supply, two 125 amp fuses, and a 40 amp trip. The 40 amp trip seems most likely, to be able to test I removed battery casing and the 40 amp trip from the casing, I had pressed the reset a few times yesterday, but maybe there was some strain on cables that stopped it resetting, but did not press it today.

Any thermal trip in motor would not cause volt meter to show zero.

 

[Jackrae]

Not on the main supply, two 125 amp fuses, and a 40 amp trip. The 40 amp trip seems most likely, to be able to test I removed battery casing and the 40 amp trip from the casing, I had pressed the reset a few times yesterday, but maybe there was some strain on cables that stopped it resetting, but did not press it today.

Any thermal trip in motor would not cause volt meter to show zero.

But it would if the 40A trip was in the main supply system. Since the batteries will be in series to provide a 24volt system a single thermal trip in any of the three/four battery lines will act as full system overload protection. 125A fuses in the individual battery circuits appears to be grossly over-rated. Are they original manufacturer fuses or replacements fitted by third parties. Do you have a wiring diagram that you can share.
Edit: Have just read the user manual and noted it states each battery has a 125A fuse so not an unauthorised 'up-rating'. I note the maximum slope specification is 10degrees so maybe just an overload trip.

 

[ericmark]

Battery 1

Battery 2

Fuse charging

Overload

Dash fuse

Clearly no fuses ruptured as working again, as to if overload not sure is 40 amp and scooter rated 270 watt, so at 24 volt around 12 amp, so should not be anywhere near the current to cause it to trip, on another forum some one said he had a problem with multi-connectors on battery if pin not engaged, but since fault cured its self I have not a clue why it failed.

The scooter was my mothers to start with, never had a problem, lent to father-in-law he never used it, just left it on charge in garage, and when he died we found one cell had gone short circuit causing the other battery to over heat so had to fit two new batteries. This was start of lock down, so never used.

So I thought good idea to give it a test run, I live around ½ mile from doctors so used it instead of walking or bike to pick up pills. Got down OK, but on return quite steep, as I reached the less steep area the was a bang as the brake engaged and volt meter went to zero.

So took brake out of drive and started to push, after trying to reset overload, left ignition on so if it reconnected it would beep at me as brake removed. Last bit down 1 in 4 approx and with no brakes was not going to try, so took to top of house, and dismantle carrying down one part at a time, left until morning, then opened the battery case with over load in, as could not test battery assembled, found not fault 12.4 volt at battery, other battery also 12.4 volt so rebuilt, tested and all worked, so put on charge.

It did not take long to recharge

I actually monitored the charge rate ignore average daily usage that was kia car on charge before the scooter. It is still on charge at average of 6 watt, will take off charge tomorrow. I have always complained there is no way to charge batteries and leave the main part of scooter in the car, real pain having to have whole scooter built up to charge batteries.

 

[ericmark]

I am starting to wonder about charging, I thought the charger could be left on 24/7 365 days without problem, and you unplugged only to use the scooter, however now day 3 on charge, and still taking an average of 6 watt, OK at 24 volt that is only 0.2 amp, but I had expected the charger to auto switch off.

 

[Harry Bloomfield]

I am starting to wonder about charging, I thought the charger could be left on 24/7 365 days without problem, and you unplugged only to use the scooter, however now day 3 on charge, and still taking an average of 6 watt, OK at 24 volt that is only 0.2 amp, but I had expected the charger to auto switch off.

I just found this old thread linked to, from another recent thread. I provided my partner with a scooter, long ago, before she passed away. She never really used it, so it was like new when she passed away, after which, I made a little half hearted use of it, but then gave up. One day, I went in the garden hut, where it is stored, and realised I had left it switched on the last time it had been moved, and batteries totally dead. One seemed to recover, the other not., using a smart charger.

Moving on several years, to this year, I decided it would be handy for me locally, so I bought a pair of batteries, and disposed of the obviously dead one. Since when, I have made good use of it. Rather than just simple series connection, to provide 24v, it seems there might be a centre tapping for something, needing 12v - I'm wondering is that 'something', might be the control system, which might explain the one battery being wrecked, when it was left switched on?

So far as recharging goes - The quite tiny SM charger, has three LED's, power, charging, and green charged, plus a tiny cooling fan. My regime after use is - to switch off, pull the key part way out, plug the charger in, then leave it for an hour or so, until the green charged LED is lit, then unplug.

The one battery which seemed OK, seems to hold up well, as a 'bench battery', for testing.