Not turning on. Blue light flashes then turns off
Fixing a Jabra with charge problems, demonstrated by the LED just flashing once when placed in the docking station/charger..
When my Jabra stopped charging after lying several months
unused in a drawer, I looked around on the internet for a way to get it to
charge again. All the methods to recover the battery that I read on the
internet are probably dangerous for both the Jabra and the user. So here is a
relatively safe and tested way to recover the battery.
Please note, Jabra does not supply any spare parts, there
are none.....so fix it or throw it in the trash.
Its a good idea to charge them every 3-6 moths, to stop the
problem ever happening to you.
I know this fix I will describe here works on both a Jabra
200 and a 250. I would expect it also to work on the 250V as well, though I
have not had a problem with mine up to now.
Some other Jabra models, especially if they demonstrate the
same problem as defined in Problem definition below with the indicator LED, may
also be recoverable in the same way. Its worth trying.
Don't forget that all Jabras are designed as "throwaway",
never to be repaired....that is probably true of most if not all Bluetooth
headsets....Jabra models 200 and 250, I find to be the most comfortable ones to
wear for long periods, whilst driving for example.
First let me define the problem for you. If the battery in
some Jabras (I cannot say all as I don't know if that is true), gets too deeply
discharged by non useage, the charger will not recharge it. The indication that
this is the problem is also easy to checkout, just stick the charger in a wall
socket, connect the docking station and while watching the indicator LED on the
Jabra, slip the Jabra into the docking station. If the LED just blinks once,
you have the discharged battery problem. Probably fully recoverable if you are good with your fingers and have
some knowledge of electrics or electronics.
The only way to get the charger to restart, is to get the
battery charged to at least 3 volts (its a 3.7 volt battery).
The best and safest method is to get hold of a lab power
supply with adjustable voltage and current. I set mine to a fixed 3.7 volts and
maximum of 300 milli amps. If you do not have access to such a power supply,
look further down this article for a method using either 2 or 3 dry batteries,
depending upon the type of battery and the terminal voltage available.
You will also need a voltmeter for either method.
Remove the tiny crosshead screw that holds the Jabra
togetherand gently and very slowly pull the headset apart, the wires are easily
damaged, are very short, fragile and difficult to repair if you break them.
The Battery is obvious, but how to get to the contacts is
not that easy. Carefully slip the battery out of its location and peel away the
insulating tapearound the top end where the charger PCB is also mounted.
Identify the + and -
of the battery either by either looking at the label (usually on the other side
of the battery to the connections) or by measuring the voltage still on the
battery and at the same time identifying which pole is the plus. Mark it.
Usually a problem battery will have around 2.3 to 2.4 volts or less....
Apply the voltage/current that I detailed before from the
lab supply (Plus to Plus, minus to minus) and watch the current meter on the Lab power
Supply unit, it should go slowly down as the battery charges up. Stop charging
for at least 10 seconds after 1 minute or less, constantly check battery
temperature at the same time with a spare finger. If the battery starts warming
up. STOP CHARGING. Let the battery cool down.
Always wear protective glasses in case the battery explodes.
Measure the battery voltage from time to time and once it is
over say 3 volts, stop charging and attach to the docking station and see if the
charger will now charge properly. If not, charge for another minute or so.
If it charges properly,carefully put the Jabra back together
and continue charging.
First charge cycle after "Repair".
The first full charge after such a repair may take up to 12
hours before the LED finally goes out, even though a "normal" charge
will generally only take 2 hours. This demonstrates clearly how run down the
battery really is/was....
Another method to recharge the Jabra Battery for those
without a Lab power Supply.
Connect 2 x 1.5 volt (NOT 1.2 volts cells as they will not
charge correctly) together, or 3 x 1.2 volt cells together and use them to
charge the Jabra internal battery with.
Monitor voltage and battery temperature constantly, till the battery voltage is above 3 volts,
then try the normal charger as before. Do carefully iIdentify the positive and
negative sides of the battery and apply the battery positive to the + side of
the battery. The other polarity to the - side of the battery.
Take your time when charging and monitor both the battery
voltage and its temperature carefully.
A series resistor may be used to keep the maximum current to
a set maximum....say 10 or 20 Ohms.
May 29, 2013 |