Checking a Gtech Battery

[bluenose1940]

Hello folks,

Does anyone know how I can check a Gtech vacuum Battery please.  I need to check the Battery to see if it has died completely (or not) and the charger if possible to see if it capable of charging.  I have a multimeter but I wouldn't know where to start as there are numerous connections where the Battery clips onto the vacuum, it looks like six little terminals.  The end of the charger looks like the type that would plug into a torch or something similar.

I wouldn't know what setting to use the multimeter and exactly where to put the probes.

Any help will be much appreciated.  Thank you.

[Herbie]

I don't think it's an easy thing to do Geoff.

According to our Gtech Battery it's 22V, so unless you have an 'auto-ranging' meter like the one in the photos below, you would set your meter to the DC voltage range that is higher than 22. One of my meters has a 20V range and the next one up is the 200V range, so that's what I'd need to use on that meter.

That's the easy bit.

The problem is that you can measure the voltage but I don't think that information is of much use, because you can't test the circuitry that's also in the Battery pack, so you won't know if it's the batteries themselves or the electronics that are at fault. It's possible that the electronics are there purely to drive and control the charging LEDs but I don't know; it may also have some current-sensing stuff in there to control rate of charge and to stop it from overcharging.

Looking at the Battery terminals on the outside of the case, at each side of them is a T9 Torx screw. Undo those and you can open the case. At the opposite end to the charger socket is a row of solder 'blobs', one slightly out on its own at the left and then 5 others next to each other like so: x  xxxxx

The one to the left on its own is the positive so put your red probe on there. Use the black probe to touch each of the other points in turn, starting at the left. I'm not sure how this will look when published but it should hopefully work:

                x              x        x        x        x        x
              +ve          0V    22V   18.7V  18.7V  0V

EDITED TO ADD - you can test the charger by plugging it into the Battery and putting your test probes on the back of that connector. The charger output is 27V.

[bluenose1940]

Hello Herbie, what a splendid reply, thank you so much.  Yes I do have an Auto-Ranging meter similar to yours.  I will follow your instructions and see what I can find.  Any thoughts on what the charger might be pushing out?  I would have thought that I would put the red probe down the centre hole and then the black one would touch the outer bit, does that sound about right?

Thanks again for your help, very much appreciated.

[Herbie]

7 minutes ago, bluenose1940 said:

Any thoughts on what the charger might be pushing out?  I would have thought that I would put the red probe down the centre hole and then the black one would touch the outer bit, does that sound about right?

I think I've answered that in an edit that I must have been doing while you were reading the post Geoff  

Yes, you can do it that way if you prefer mate 

[bluenose1940]

Thanks again for your input Herbie.   Both of the chargers seem to be OK.  One of them gives a reading of 27v and the other shows 26.9v.

As regards the batteries, I cannot get a reading of any sort from either of them.  The one Battery is for the hand held vacuum and the other is for the actual carpet sweeper type vacuum.

Do you have any idea as to the slots on both batteries that appear to be similar to what a USB cable would plug into on the rear of a printer?  I can't imagine that you could charge these batteries from a USB connection.....................................or can you?