1.5 volt Li-ion rechargeable batteries

[MRMILSTAR]

Has anyone had any experience with the 1.5 volt lithium-ion rechargeable batteries? One consists of a normal 3.7 volt li-ion battery with a built-in buck converter to bring the voltage down to 1.5 volts. The primary operational difference from a conventional battery is that the output drops abruptly to zero when the battery is fully discharged.

I have been experimenting with the AAA size. One has failed completely. It seems to me that there must be a small constant drain on the battery even when not connected due to the buck converter drawing some small amount of power in the quiescent state. Does anyone know?

[davekni]

I've tried two brands, one in AAA and both in AA sizes.  Tried EBL first.  Been very happy with their "9V" batteries with two LiPoly cells inside and a protection circuit.  Meet their spec'ed 600mAH.  However, their 1.5V batteries do not meet specified capacity.

Then purchased some Hixon brand AA cells.  Those meet (within reasonable tolerance) specified capacity.  They also taper charge rate near end of charging, so are easier on internal cell.

Yes, both have some small drain when idle.  Drain drops to essentially zero when internal cell voltage drops below ~3.6V.  That is a great feature, as cell does not continue to drain to the point of long term degradation.

The internal buck converter takes a short time to ramp up for sudden load from 0.  This shows up as an issue when running analog clocks that draw ~0 current except for short bursts every second to move mechanism.  Especially with the EBL AA cells, buck didn't always recover in time.  Clock thus gets stuck every now and then.