Hi,

I am using my HP 50g at work every day for simple calculations in order to test some Philips 1000mAh NiMH batteries. I have to charge the batteries, roughly, once a week but I read in the forum a post where someone was getting two weeks of usage using similar (1000mAh NiMH) batteries in the worst cases and even ten (!) weeks in the best.

So my question, for those using NiMH batteries in theirs 50g: is there a particular brand that you may recommend for the 50g to obtain longer usage time between charges?

Thanks and regards,

Miguel

I recommend this brand :

http://en.wikipedia.org/wiki/Eneloop

friendly.

Second on the Sanyo Eneloops!

Definitely Panasonic/Sanyo eneloop.

I use pre-charged, slow discharge NiMH batteries whenever I can find them in just about everything. Eneloop is the main name here, but I am okay too with pre-charged Duracells. I use them in photo flashes, kid's toys, wireless mice and keyboards, etc. Suckers last forever, and require infrequent recharging.

Indeed, I really wish I could find slow discharge NiMH cells in 2/3 AAA size for my HP41s. Still, the standard 400mAh NiMHs I use are faring well so far.

Les

I think I was the OP you spoke about. I'm using a brand that (in the UK) is called "Energizer recharge" (1000mAh). They're shiny silver with black and green writing.

In nearly everything else I use white Eneloops, and I agree with the others that they're awesome batteries. I've stuck with the Energizers simply because I bought them before the Eneloops, and they just happen to live in my 50g (an equally awesome computer!).

Edited: 13 Nov 2013, 8:13 p.m.

I also recommend the slow discharge Sanyo eneloops or similar Panasonic types.

A little while ago I tried so called "rechargable alkalines" which are sold under the brand "iGo Green" here in Germany. They require a special charger, have a very slow self-discharge and provide the full 1.5 Volts per cell instead of the 1.2 V for the NiMHs.

However, after short use and about 3 recharging cycles I noticed that two cells out of 8 began leaking.
I will need to investigate this a little further, but so far it seems that they are just getting too hot in the charger, causing the safety vent to break open.

Has anybody else had similar experience?

A number of years ago, a UK retailer sold Rayovac brand rechageable alkalines, and I bought several packs at that time. They were better than contemporary NiCads for equipment in intermittent use. However I did have an instance of cells leaking within an appliance (i.e. not during charging). I reported this to Rayovac, who sent me a couple of packs of new cells in response, and IIRC also asked me to return one of the leaked cells to them for investigation.

It was some time before I put the replacement cells into use, but I did eventually and I'm still using them now. However, they have lost quite a lot of capacity, and I now use them mainly in some decorative LED lights which have fairly low consumption. I've had no more leakages, and the cells must by now be at least 10 years old.

The two chargers I bought for them have the advantage of having individual channels, so are handy for charging odd numbers of cells. They seem to have quite sophisticated circuitry, and I have used them to revive cells that other chargers didn't seem able to do much with.

Hi,

I will go with Eneloops. Thank you very much for your answers,

Regards,

Miguel

Look on TAS. Depend on whether you go with an Asian or US seller, and how many you buy, you pay about 3 to 4 bucks per cell all in. I would splurge the 24 to 26 bucks for eight.

Les

The Eneloops are great. But please do not forget to use a decent charger. A processor-controlled device that handles every single battery separately and terminates charging reliably. Without a good charger even the best batteries will fail.

Dieter

Dieter:

Re chargers, where might one find one such as you reference. I have an Energizer brand charger, made in China I expect. It charges AA and AAA.

Recharging 4 AAA for a 50 G calculator runs over night, 11 hours or so. One of these days, I must sit down with the 50 G and instruction books I have and learn to use the thing. As it is, I rely mostly on a 20 + year old HP 11C.

Dieter:

Re the Eneloops, where does one find them. Also, what of the chargers you reference. I have an Energizer charger, likely made in China.

Thanks.

Al

Dieter:

Excuse the double post, operator error.

Over here, the BC700 charger (as well as its siblings) has a very good reputation. It is compact and offers various functions for charging, battery analysis and more. Maybe you want to download the manual and see what this device can do. The charging current can be adjusted, its default value is 200 mA which IMHO is perfect for the 800 mA AAA Eneloops. This means the relative charging current is C/4 (approx. 5 hours for a completely empty battery) which is fast enough and should not warm up the battery too much.

Of course you can get this charger at Amazon, cf. this link. You will also find various Eneloops there. Simply take the classic white ones.

Dieter

Edited: 16 Nov 2013, 3:41 p.m.