Multimeter usage!

hopper1

How the fcuk do they work? :?
I bought some lights (MS) but something seems wrong...
I bought a multimeter to check all possibilities, but instructions are a) Very vague. b) Assume I'm a time served sparky :shock:
I want to check the battery pack, charger & light itself, if possible.
Anyone fancy trying to explain that lot in laymans terms? Words of 4 letters, or less please

In case it matters, I have a Challenge (Very challenging!) 28 position Digital Multimeter

hotnajers

its difficult to tell you without seeing anything, the first thing is make sure the connections are tight if this is a dynamo make sure you have agood earth to check the battery set it to dc voltage and put the red probe to the+and the black probe to the -and note the reading , if it has a cotinuity setting use this to test the wireing put one probe to one end and the other to the other end if the connections are ok a buzzer should sound.

hopper1

Not a dynamo.
It's one of these.
When charger is plugged into socket, the LED goes green, without being connected to battery pack!
Vice versa, charger LED goes green when connected to battery pack, but before being plugged into wall socket!
Neither give off much in the way of heat during charging...

ademort

Hope this helps.I have the same light as you. When you plug in the charger the light goes onto green without being connected to the battery pack as you said in your post. When you connect the battery pack to the adapter it should then give a Red light, it,s then in charging mode. When the battery is fully charged it will then go to Green. You are right about the instructions there were none with my light hope this helps.Further to the above, if you connect the charger to the battery pack without plugging in the charger it will give a Green light.
Ademort

Runoutofgears

Mine charges as ademort's description, it requires a bit of an act of faith when starting out with this set of lights. I had to look the product up on the web to get an approximate charge time due to lack of instructions! Mine barely warm up when charging.

hopper1

Ok, thanks guys.
Some further developments...
Battery charger light no longer turns green when plugged into the battery pack!
Doesn't go red at all. I took the charger apart, and couldn't see a red LED, only a green LED!
The battery pack is currently showing 5.8v on multimeter.
When I first connected the battery pack to the light, it lit for a split second. I then had to use the button at the back to operate it.
I decided to run the batteries down to nothing, then start again with a fresh charge.
After about 10 mins, the light went out (suddenly). It wouldn't restart, either.
I left the light to cool ( I thought maybe the heat had tripped it). Still nothing.
Is it possible the driver is naff, or I have a loose wire?...

rake

i shall assume your light uses a lithium polymer battery. seeing as no usefull instructions were given il try and put you in the picture. lithium polymer batteries are killed permanently if they are allowed to fully discharge due to a change in their chemical make up. if there are batterys(3.7v per cell standard for lipo) in series to give a higher voltage output when they go flat one will reach 0 volts before the other due to slight variances in the amount of charge each battery can store. this causes the negative terminal on the battery at 0v to be at a higher voltage than the positive terminal on the 0 volt battery because the other battery which still has some voltage is connected to it. This is called reverse charging and quickly kills lipo batterys permanently. For this reason any gadget using them will automatically turn off when the battery pack goes below a predetermined voltage to protect them from reverse charging/full discharge nasties. Your device was perfectly fine to suddenly switch off when you ran it down , this shows its working. you may notice your mobile phone/ ipod does the same before the screen goes dim. exactly the same reason.
you say there is no red led but when you had it apart look at the bottom of the green led, if it has 3 (or more)connections rather than just 2 its a multicoloured led that can shine more than one colour (red/green/blue). avoid switching the light on while the charger is plugged into it , this could draw more current from the charger than it can handle.

you say the green led no longer comes on, it may be charging try leaving it for the full charging time and see if the green light appears again to indicate its fully charged.

hopper1

Thanks for entering the fray, Rake.
I forgot to mention the batteries (4) are Li- ion, 18650's, 3.7v each
They were just on charge for 3 hours and never moved higher than the 5.9v they registered at the beginning.
this is the light in question...