Jump to content
House Price Crash Forum

Archived

This topic is now archived and is closed to further replies.

Guest redwine

Re-chargeable Batteries

Recommended Posts

Guest redwine

looking for some re-chargable batteries size LR03X1.5V for our telephone the same size as an mp3

we changed the telephone 6 months ago at first you could spend an hour on the phone (the missus) but now its down to 15 minutes so i will have to change as "she" is not happy about this

i looked in the shops and they are not cheap i do not mind paying the price as long as they last a long time afterall they are on charge 24 hrs a day

its not a question of paying the telephone bill as i pay internet telephone etc for xxxeuros every month

its the same with those low energy lightbulb's i feel like i am in the "dark" better off with a candle

any suggestions ?

Share this post


Link to post
Share on other sites

According to a Google search I've just done, I think that LROX3 is the same as an AAA battery.

You can get AAA rechargeables at virtually any supermarket.

If it's going to be constantly on charge, get Nickel Metal Hydride batteries (NiMH), not Nickel Cadmium. The latter suffers from memory effect - NiMH ones don't. For something like a cordless phone, which sits in its charging cradle pretty much all the time it's not in regular use, a NiCd battery will be knackered through memory effect pretty quickly. You should only recharge a NiCd battery after it's almost totally drained.

The capacity of a rechargeable battery is measured in miliamp hours. For an AAA, 400 is low, 600 average and 800 high. The bigger the capacity, the longer they'll go between charges but they cost more. As a general rule, a consumer NiMH battery will go for 100-150 charge and discharge cycles before the lifetime starts to diminish noticeably.

Share this post


Link to post
Share on other sites

Confession time - I once spent an entire summer as a student testing different battery technologies and charging profiles for mobile phones.

The basic issues is that batteries "wear out", not in the way a gearbox does, but essentially the physical structures of the the chemicals within them can change. So NiCads (an older technology) suffer from a structure called dendrites, these are structures that grow that can short the battery. Batteries with dendrites can be revived for a while by putting a high current across them which blows the dendrites.

Another issues it what is know as the memory effect. This is where the cells are partially discharged, then charged, partially discharge and charged and so on. The battery "apparently" remembers this, which results in a lower voltage at a given level of discharge which can cause issues for some electronics.

These are the main issues with NiCADS and NiCAD basically need the correct charge/discharge regime, ie a good high current charge periodically and deep discharge.

Other technologies have other issues. NiMH batteries are better in terms of the issues above, but actually they hate being deep discharged as this can damage the cell and lower capacity.

So my guess is that you probably have the wrong charging regime. Mobile phones tend to get round these issues with clever electronics to manage the charging of what are now mainly Lithium Ion Cells, but cheaper gadgets like cordless phones tend to use NiMH or even NiCAD and often leave out the clever battery management electronics.

Share this post


Link to post
Share on other sites
Guest redwine
According to a Google search I've just done, I think that LROX3 is the same as an AAA battery.

You can get AAA rechargeables at virtually any supermarket.

If it's going to be constantly on charge, get Nickel Metal Hydride batteries (NiMH), not Nickel Cadmium. The latter suffers from memory effect - NiMH ones don't. For something like a cordless phone, which sits in its charging cradle pretty much all the time it's not in regular use, a NiCd battery will be knackered through memory effect pretty quickly. You should only recharge a NiCd battery after it's almost totally drained.

The capacity of a rechargeable battery is measured in miliamp hours. For an AAA, 400 is low, 600 average and 800 high. The bigger the capacity, the longer they'll go between charges but they cost more. As a general rule, a consumer NiMH battery will go for 100-150 charge and discharge cycles before the lifetime starts to diminish noticeably.

the batteries that i have in my telephone are NIMH AAA 600 1.2 V they sell them in packs of 4 costing 16 euros all i need are 2 batteries not 4 but i think that 6 months is a short lifespan unless they are faulty

how long are these these batteries meant to last ?

Share this post


Link to post
Share on other sites

That price sounds a bit steep. The last time I replaced the batteries in my cordless, I think a pack of 4 800 ma/h AAAs cost around £7-8.

I generally replace them around every year to eighteen months, but there again I don't use the phone that much (I'm probably on it for about an hour a week - no more).

Other technologies have other issues. NiMH batteries are better in terms of the issues above, but actually they hate being deep discharged as this can damage the cell and lower capacity.

Interesting - didn't know that. Would it therefore be an idea to charge up my NiMH mobile phone, shaver etc. significantly before the low battery alert comes on?

Share this post


Link to post
Share on other sites
Confession time - I once spent an entire summer as a student testing different battery technologies and charging profiles for mobile phones.

I hope that was work, and not your hobby! :P

Share this post


Link to post
Share on other sites
Confession time - I once spent an entire summer as a student testing different battery technologies and charging profiles for mobile phones.

The basic issues is that batteries "wear out", not in the way a gearbox does, but essentially the physical structures of the the chemicals within them can change. So NiCads (an older technology) suffer from a structure called dendrites, these are structures that grow that can short the battery. Batteries with dendrites can be revived for a while by putting a high current across them which blows the dendrites.

Another issues it what is know as the memory effect. This is where the cells are partially discharged, then charged, partially discharge and charged and so on. The battery "apparently" remembers this, which results in a lower voltage at a given level of discharge which can cause issues for some electronics.

These are the main issues with NiCADS and NiCAD basically need the correct charge/discharge regime, ie a good high current charge periodically and deep discharge.

Other technologies have other issues. NiMH batteries are better in terms of the issues above, but actually they hate being deep discharged as this can damage the cell and lower capacity.

So my guess is that you probably have the wrong charging regime. Mobile phones tend to get round these issues with clever electronics to manage the charging of what are now mainly Lithium Ion Cells, but cheaper gadgets like cordless phones tend to use NiMH or even NiCAD and often leave out the clever battery management electronics.

How disappointing.

There I was prepared to pitch in with a load of hearsay, speculation and pub talk and along comes mike with some real knowledge.

What a miserable git. :P

Share this post


Link to post
Share on other sites
Guest redwine
That price sounds a bit steep. The last time I replaced the batteries in my cordless, I think a pack of 4 800 ma/h AAAs cost around £7-8.

I generally replace them around every year to eighteen months, but there again I don't use the phone that much (I'm probably on it for about an hour a week - no more).

Interesting - didn't know that. Would it therefore be an idea to charge up my NiMH mobile phone, shaver etc. significantly before the low battery alert comes on?

thanks

i thought that they would of lasted at least a year and the 16 euro price i quoted were the cheapest but an unknown brand

or maybe it could a problem with re-charger

Share this post


Link to post
Share on other sites
thanks for the link but they don't sell outside of the uk and ireland

the only place to buy anything cheap in france is Aldi

Yeah well Aldi might have some, they periodically have them on special over here. They're very cheap when they do, though not especially high quality.

If the cordless phone just dumbly constantly charges the batteries they've probably died of overcharging. But in any case, the rechargeable batteries that you get supplied with phones tend to be complete rubbish. I put some Aldi/Lidl rechargeables in our cordless phones after we got them at a boot sale and they've been good the whole time we've had them, which is probably a couple of years now.

Oh, and about the memory effect:

www.dansdata.com/gz011.htm

Share this post


Link to post
Share on other sites

  • Recently Browsing   0 members

    No registered users viewing this page.

  • The Prime Minister stated that there were three Brexit options available to the UK:   296 members have voted

    1. 1. Which of the Prime Minister's options would you choose?


      • Leave with the negotiated deal
      • Remain
      • Leave with no deal

    Please sign in or register to vote in this poll. View topic


×

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.