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Cordless Phones with High Tech Batteries?
ewieling asks: "I will be replacing my current corless phone soon and was wondering if there are any cordless (not Cell) phones that have something better than a NiCad battery. My current cordless phone had great battery life when I first bought it, but soon the battery life degraded until now I only get about 10 mins of talk time out of it. I tried to avoid the 'memory' problems of NiCad batteries, but I still get very little talk time now. My current cordless phone is a high end (at the time I bought it) Panasonic with a keypad, LCD display, speaker phone and headset jack on BOTH the base station and the cordless handset and uses the 2.4 Ghz range, but it still only has a NiCad battery. Can anyone help me find a good cordless phone with the above features that uses better battery technology."
Just buy the phone you want and replace the batteries. Batteries Plus can order almost any size cell you want in NiMH. You'll probably have to do some soldering, but that's easy.
Also, Siemens phones use standard AA rechargables, so you could replace these with NiMH AA's.
I don't think you can do Li-ion in phones that come with Ni-cad batteries, as Li-ion typically requires more voltage than they put out to charge.
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They're really cheap. You can get replacement cordless phone batteries from most decent electronics shops for a couple of pounds - sometimes they're actually cheaper than similar-sized ordinary nicads.
From my use of batteries and what I've read on the matter, here are a couple of suggestions:
;)
1. Use Nickel Metal Hydride (NiMH) batteries - I'm sure there will be a thousand posts on this.
2. Keep you batteries charged!!! With NiMH, if the battery is discharged it looses hydrogen at the anode and thus looses capacity. With NiCads, it means the deactivation of reactants which yields the same results. That means keep the phone on the charger when not in use.
3. If you feel the batteries are loosing their capacity to recharge, the best thing to do is to drain them completely and recharge them at least twice.
Just my two cents
See my previous post about how to have less trouble with NiCad batteries:
Solutions: 1) Don't charge so much. 2) Discharge.
Someone responded to that post with a link to a PDF file. The PDF file contains interesting information, but is too detailed for most people. It mentions that often the memory effect isn't really memory effect, but another process that has the same cure.
I agree that it is good to replace the NiCads with NiMH batteries. But it is possible to live with NiCads if you observe their limitations. It is possible that a particular device designed for NiCads will not charge NiMH batteries well.
From the tone of your article, the phone itself sounds like it is relatively old.
Nicad batteries wear out. This is normal. They're also the cheapest and safest rechargable batteries you're likely to find, bar none.
So, just replace them. Find a well-stocked Panasonic phone dealer (amazon?) and get the genuine article, or just pick up the appropriate off-brand replacement at the department store of your choice.
While it certainly wouldn't be impossible to design a cordless phone that used rechargable lithium cells, noone seems to market such a beast to the consumer. Probably because lithium batteries are very good, very light-weight, and also very expensive. They also tend to react explosively to mistreatment during the charging cycle. Stay away from lithium rechargables in devices not expressly intended to use them. [FWIW, Motorola Startacs have a microprocessor in the battery pack itself, expressly for the purpose of lawsuit prevention - I imagine most/all other companies do the same thing, but I've never taken apart any other Li-Ion packs.]
You might be able to change the nicad cells with NiMH, but you're not likely to get any net benefit from the exercise. Besides, NiMH suffer severe stamina problems after being charged for too long at one time, which is something that chargers designed for this type account for, and your cordless phone does not.
So. With NiMH, you'll have to remove the cordless phone from the base after no more than 12 or so hours of charging, followed by a substantial drain before the next re-charge. Unless you're able to do this every time you charge it, and are able to train your friends and family to do the same, I'd avoid a NiMH retrofit, unless you anticipate and accept that permenant battery damage will result. [At least they don't tend to explode, like lithium batteries do...]
And at any rate, if you had the discipline to follow such strict procedures, you'd have plain old, cheap NiCads that last forever, just like me.
I've got a 4-year-old, vanilla, Uniden 900MHz analog phone. It works well, having great audio quality at long distances through any number of obstructions.
I replaced the stock battery after a year or so with whatever compatible type Sears had at the time, and things have been golden since.
Tricks:
I use the phone until it's either inoperably dead, or starts in with its low-battery song and dance (blinking light, funky stutter ring when someone calls). When this happens, I place it on the charger, and leave it there until at least the next day. When I feel like using it again, anywhere from six hours to six days later (depending on alcohol intake), I keep it off the charger until it is once again dead. The whole cycle takes from 5 days to just over a week, depending on use.
Those who are keeping score will note that I've got three years of outstanding service from a cheap Sears battery. It takes a slight effort to keep things in-check, but the system (as a whole) is reliable and predictable, which is really all that matters.
That all said, I echo your sentiment: I've got a Nokia cell phone with their smallest available lithium battery. I only ever use it with the cheap, third-party charger I have in the car, which cooks the battery completely in just over an hour. Routine fast charging like that is supposed to always be bad for batteries. But Lithium batteries seem to Just Work(tm) no matter what I do to them, and I still get great talk time and days worth of standby. Must be that microprocessor...
I'd love for a cordless phone manufacturer to start using modern battery systems. I'm even willing to pay extra for it the convenience of not having to bother with the proper care and feeding fo the battery.
Even my UPS, a Best Ferrups 850, maintains its sealed lead-acid battery (a Panasonic) automagically. Once every 1 or 2 weeks, it'll switch over to battery power for a few minutes at a time. It then tops off the battery again and resumes keeping it on float charge. This is all part of the normal care and feeding of a lead-acid battery (your car does it with its battery, too, by virtue of you running the starter motor), but most UPSs don't do it at all. OTOH, I suppose this is no ordinary UPS, but why can't phone manufacturers adopt at least semi-modern battery technology? NiMH would be a good, safe, and inexpensive start. Even my RioVolt came with a pair of AA NiMH batteries, and enough smarts to avoid abusing them.
Good luck!
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Let's assume that you're replacing the phone for reasons other than the amount of talk time that the current battery is providing you with. As others have pointed out, if talk time is the only problem then replace the darn batteries and move on... :-)
If you're buying a new phone, look for one that uses standard size AA rechargable batteries, instead of a proprietary battery pack. A phone that can handle NiMH batteriers is somewhat preferable to ones that can only use NiCAD batteries, but since NiMH batteries cost more I'm not sure that they are really worth the extra cost.
There are several advantages with standard size AA rechargable batteries. One is that you can purchase replacement batteries from any good electronics shop. Another is that if talk time consinues to be a problem then you can always buy a second set of batteries and an inexpensive stand alone reconditioning charger, and swap batteries back and forth between the phone and the charger. Note that the charger should have a reconditioning circuit (cheap ones don't).
There are several good inexpensive chargers on the market. I use a MAHA brand charger, which I purchased from Thomas Distributing. I have used it to recharge both NiCAD and NiMH batteries with good results.
Let's put this falsehood to rest already:
NiCd Batteries do NOT have "memory"
Anyone care to hazard a guess as to why rechargable battery makers don't put out 1.5V rechargeable batteries and kill off alkalines once and for all?
It has something to do with the chemistry of the battery. It's been a while since I took chemistry so someone chime in with corrections if needed.
Most every battery work in the same basic manner in storing the charge in an electro-chemical process. The charge is stored in the creation of a bond and then released as the bond breaks. The difference is in the elements used in the reaction. The different elements each have a different "voltage" associated with it which is based on where it lands in the periodic chart. The futher apart they are on the table the greater the voltage that can be produced in the reaction. The elements used in an alkaline cell are spaced 1.5 volts apart, a Ni-Cd cell uses elements spaced 1.2 volts apart and so on. A 9 volt alkaline battery just has 6 cells inside to achieve the rated 9 volts, similarly with a 12 volt car battery and other true batteries (not "cells" which are commonly called "batteries").
So to answer your question why someone doesn't just make a 1.5 volt rechargable is because the chemistry becomes too complex to fit in one little cell and still get a reasonable capacity. It is easy to make a "one-shot" alkaline because the reaction only has to go one way. It's kind of like storing heat in wood, it's easy to burn the wood for heat but it's more complex than heating up the ashes to get the wood back to a burnable form again. To get a cell that could recharge easily meant choosing elements different than those used in a traditional alkaline cell, ones with a different natural voltage difference.