Why I Don't Use Protected Bats.

[Johnny2Puffs]

If you use protected bats and let it run too flat, it might not recharge. Or if you store a flat protected bat for a long period then it definitively will not charge again. You may as well bin it.
Reason being is that the electronic protection circuit built into it needs a certain minimum voltage for it to operate continually and if this voltage is too low, it will stop working.
When this stops working then it will not allow the charger to charge it.

Same with laptop bats and cellphone bats. How many cellphone bats have you dumped because you let the
voltage drop too low?
There is actually nothing wrong with these bats. The problem lies in the cheap chargers that come with the
stuff. You will need a charger with a boost circuit to awaken the protected bat and they are expensive.

 

[CraftyZA]

The alternative that has worked for my k-Jam back in the day was to connect another battery in parallel as you hook it up to the charger. You only need the charger to acknowledge the battery, then it will supply the power. so for 2 or 3 seconds charge, then remove the secondary battery, and tell your self to charge it sooner

 

[Johnny2Puffs]

Yes. That will work as will other methods that I do not recommend and will not mention them.
One is to boost it with a car bat for a few secon... Wait. let me rephrase.
Tell your gardener (he works for you and you pay him) to connect the car bat to the e-cig bat for a few seconds while you stand well back. He must do this at least twice. Not too long as the bat gets hot and your gardener might just loose some fingers. Now plug it into the charger and it's good again.

Just another triviality. Some BlackBerries are prone to early bat retirements due to this problem. Now most cellphones have the protection circuit built into the device and not the bat.
If the bat is too low to power this circuit then the device will not enable the voltage from the charger to reach the device pins that connect to the bat.
To overcome this is to simply ask any Paki cell store to charge the bat with a Universal charger. This is a charger that charges bats directly without your cellphone.