L
Lincolnshire poacher
Guest
My Oldham lamp has developed an odd fault. Lamp is a grey headset with red bezel and the battery got the 2 holes/vents in the side. Genuine Oldham charger as well.
Was going down a couple of mines at the weekend, so put lamp on charge on Frday night. Charger said it was done after about an hour. Got to the first mine, and after about 45 mins the light (main beam) starts to dim big time....time to get the back up torch out.
Get home on Sunday and check battery voltage, which was 4.42v. Put the lamp on charge and waited for it to finish, which it did after about 30 mins. Left it on to see how long it lasted, this time it was about an hour. Checked the charger is ok. When the lamp head is on and charging there is 5.02 volts going into lamp (instructions say 5.17v is correct voltage but am allowing for multimeter not be calibrated). Just as lamp reaches the finished stage ie ready light on, you can watch the volts drop off to 'float voltage'.
So at this point I'm assuming:
The charger is ok
The battery is Knackered
Just out of interest I swap lamp heads for my spare (same main bulb as previous head) Again charging time is about an hour. Lamp spent today in my van, was going to get battery tested but ran out of time. Turned lamp on tonight when I got home (17.00) and as of now it is still at what I would call normal brightness.
So, if you've got this far and can understand what I've written, what has gone wrong?.
Do I have a duff lamp head?
Or do I have a dodgy battery?
Was going down a couple of mines at the weekend, so put lamp on charge on Frday night. Charger said it was done after about an hour. Got to the first mine, and after about 45 mins the light (main beam) starts to dim big time....time to get the back up torch out.
Get home on Sunday and check battery voltage, which was 4.42v. Put the lamp on charge and waited for it to finish, which it did after about 30 mins. Left it on to see how long it lasted, this time it was about an hour. Checked the charger is ok. When the lamp head is on and charging there is 5.02 volts going into lamp (instructions say 5.17v is correct voltage but am allowing for multimeter not be calibrated). Just as lamp reaches the finished stage ie ready light on, you can watch the volts drop off to 'float voltage'.
So at this point I'm assuming:
The charger is ok
The battery is Knackered
Just out of interest I swap lamp heads for my spare (same main bulb as previous head) Again charging time is about an hour. Lamp spent today in my van, was going to get battery tested but ran out of time. Turned lamp on tonight when I got home (17.00) and as of now it is still at what I would call normal brightness.
So, if you've got this far and can understand what I've written, what has gone wrong?.
Do I have a duff lamp head?
Or do I have a dodgy battery?