|HP50g and rechargeables |
Message #1 Posted by Chris Smith on 24 Dec 2012, 6:57 a.m.
Ok so I've had my 50g for 2 weeks now and the rather expensive batteries I put in it (lithium AAA) are dead as a dodo. To be fair I haven't put it down, much to the dismay of my other half.
I did some research regarding using rechargeables in it and it appears there is some confusion over battery warning voltages if you put 1.2v cells in instead of usual alkaline 1.5v cells. Basically the discharge curve of your average NiMh cell drops off pretty quick meaning the calc will starting complaining quite early.
Logic said: find some cells that have a better up front voltage than 1.2v. So some research tripped over Nickel Zinc cells which are rechargeable and have an initial voltage of 1.6v.
My local electronics shop (Maplin in UK) sell them as well:
The initial voltage of 4 cells is 6.4v vs 6v so imagine that's not too much for the regulator on the device to handle.
Has anyone tried these or does anyone think it's a bad idea before I go and buy some? Or are they snake oil?
I'm an EE by trade so I'm up for any tech details.
Edited: 24 Dec 2012, 6:59 a.m.