Relating specifically to cordless phones, what is the best way to condition the batteries?
The instructions don’t even mention it, and google seems to address cell phone and car batteries to the exclusion of all else.
The less technical sounding the answer, the better.
It depends on the type of battery. There are professional battery conditioning devices, but they are expensive and unlikely to be cost-effective for your application. To do a proper job of it, you need to disassemble the battery, test and condition the cells, replace any weak or bad cells, and reassemble the battery. You would probably be better off replacing the battery with a new one.
Okay, perhaps I used the verb “conditioning” incorrectly. Let me try again.
When you first buy a phone, you’re supposed to charge it for 16 hours or so. But then if you start using it regularly right after that – using it to talk and then hanging it up back on the cradle/charger, the battery will gradually lose some of its maximum charge.
With my old phone, I was unaware of this phenomenon, and my full charge gradually fell – in painfully small steps – from hours and hours all the way down to under a minute. (I still have that battery, though I don’t know why, as it’s now worthless as a backup.)
When I got a new battery, I decided to avoid this by never hanging the phone up on the cradle until the battery was completely dead. Unfortunately, this is annoying as shit, as it always seems to die just when I want to use it.
A friend mentioned in passing that I didn’t need to worry about it once I conditioned the battery, which involves charging it fully and then letting it die completely before another full recharge.
So I want to know the minimum number of times I have to fully charge and completely kill the battery before I can use it like a regular corded phone, hanging it up after each use and thus keeping it fully charged at all times.
Also any other relevant details, like for example with this new phone I just bought. I charged it fully, then kept it off the cradle until it was fully dead. (Which took over a week, btw, and it died in the middle of a call.) I then put it back on the cradle to charge for another 16 hours, but about an hour in I accidently knocked it off the table. I put it back on the cradle, and finished the full charge, but did this hurt the battery’s potential efficiency any?
Sounds like you are talking about battery charge memory, which I thought Cecil made a column about, debunking it for the most part IIRC. Can’t find the column now for some reason.
Also, I heard from a person selling mobile phones/services in a Circuit City that complete discharges are bad for the battery. Can’t say how trustworthy that source is though.
Ah, the term “memory charge” leads to much more information, but still not as robust as I’d like.
For example, Battery Memory Effect - What it is and what you can do about it yields this info:
Most cordless phones use NiCad batteries. To maximize your cordless phone battery life, make sure to leave your phone off the base every once in a while until it is dead. Then leave it on the base until it is fully charged. You should leave your phone on the base for at least 24 hours to charge it fully.
Even better is W & W’s Battery FAQ, which offers sections on the memory effect and how to “format” batteries: (Woohoo, another search term!)
*What is memory effect?
Also called voltage depression. This phenomenon happens in the Ni-Cd batteries. The battery “remembers” how much energy was extracted in previous discharges and try to accept that amount of energy only in the next charge. This reduces the available capacity of the battery.
Memory effect is actually a gradual change in the crystalline structure of the battery’s cell plates. This change is often accelerated by repeatedly recharging before fully discharging. Over time an alloy derivative of nickel and cadmium forms inside the negative electrode. Because of its chemical composition, this alloy has a lower voltage potential than the original plate material. If a battery is continually recharged before being fully discharged, the alloy will continue to develop and will progressively reduce the level of energy the negative electrode is capable of retaining. This reduces the available capacity of the battery.
What is formatting a new battery ?
It is the process a new battery has to go through to make sure its electrolyte can use all its capacity to store energy. This process consists of 3 or 4 charge-fully discharge cycles. W & W Analyzer has the “Conditioning Mode”, which can format the battery in less time than other analyzers.*
Not exactly in-depth, but it’s something.
From my first cite:
2. When charging your batteries occasionally discharge them fully before recharging them. This is especially helpful to NiCad batteries. Be careful not to discharge too deeply. (Less than 1v per cell for NiCad and NiMH. E.g., a 3.6v pack to no less than 3v.) Discharging to absolute zero will make your battery useless. It’s best if you have a charger with a conditioner that will cycle the battery for you.
Of course, none of this answers the original question that prompted me to post this OP. Did knocking the phone off the charger an hour into its second-ever charge affect its efficiency?
It depends on the type of battery. Lithium-ion batteries don’t have memory effects.
Do not “fully discharge” any rechargable battery. What people really mean when they say “fully discharge” is “partially discharge until the device no longer gets enough power to run.” That’s a long way from a full discharge.
Note that the W&W link Ellis Dee provides is intended to sell a product. They are essentially giving the usual sales glurge, not real info.
NiMHs do have a problem with over charging resulting in voltage depression which can be solved by going thru several deep discharges (running the device until it doesn’t power on anymore in the case of a laptop). I have done this several times successfully with NiMHs.
Don’t try it with LIons and there’s no point (IMO) in doing it with NiCads.
That’s why I mentioned disassembly of the battery. That’s the only safe way to fully discharge a battery, by breaking it up into its component cells and discharging them individually. I used to overhaul NiCd batteries, among other things, when I was in the Army.
Okay, the battery in question is this one.
What is the overcharging issue? As in, don’t leave it on the cradle for extended periods, or what?
Ideally, either it should be in use, charging up to a regular charge, or out of the circuit. For the item in question, this may not be realistic.
Our oldest cordless phone came with instructions that said it might develop a shorter battery use time and to unplug it from the phone system and the outlet for at least 12 hours. Then plug in the power, only and recharge it for no less than 24 hours before conecting it to the phone line. (This was, IIRC, to keep it from ringing, and stressing the battery) We still have the phone and it works great.