Rechargeable Batteries
Nov 21, 2023 09:38:44 #
You might have tried to charge a battery that would not charge. I've seen this on woodworking YouTube channels. If the battery is too dead, the charger will not engage with it. That happened to me yesterday with a Dremel battery. The solution with a DeWalt battery, for example, is to run wires from it to a good battery. That will give it enough charge to let the charger recognize it.
I ordered two new batteries, and when they arrive, I'm going to try that with the dead Dremel battery. I didn't want to take a chance using a DeWalt battery. Well, maybe I will.
https://www.youtube.com/results?search_query=charge+a+dead+tool+battery
I ordered two new batteries, and when they arrive, I'm going to try that with the dead Dremel battery. I didn't want to take a chance using a DeWalt battery. Well, maybe I will.
https://www.youtube.com/results?search_query=charge+a+dead+tool+battery
Nov 21, 2023 10:32:25 #
jerryc41 wrote:
You might have tried to charge a battery that woul... (show quote)
I have a general question about small rechargeable batteries. Why are the AA & AAA rechargeables rated at 1.2 v. when the normal AA & AAAs are 1.5 V.?
Nov 21, 2023 10:37:57 #
jiminnee wrote:
I have a general question about small rechargeable batteries. Why are the AA & AAA rechargeables rated at 1.2 v. when the normal AA & AAAs are 1.5 V.?
Because the chemistry is different. Alkaline batteries nominal 1.5V per cell. Zinc Air battery 1.4V. NiMh or NiCad 1.2V. Lithium ion 3.7V, lead acid 2V etc..
Nov 21, 2023 10:39:43 #
jerryc41 wrote:
You might have tried to charge a battery that woul... (show quote)
You can use a power supply to do it. You don't need a DeWalt battery. The best is a power supply with adjustable voltage and current limit. But however, I don't think it's worth it. When the battery is in that condition and you get it to charge it won't hold much power.
Nov 21, 2023 12:23:40 #
jiminnee wrote:
I have a general question about small rechargeable batteries. Why are the AA & AAA rechargeables rated at 1.2 v. when the normal AA & AAAs are 1.5 V.?
Different battery technology/chemistry. NiMH vs alkaline
Edit: sorry to be redundant
Nov 21, 2023 12:44:37 #
jiminnee wrote:
I have a general question about small rechargeable batteries. Why are the AA & AAA rechargeables rated at 1.2 v. when the normal AA & AAAs are 1.5 V.?
Different chemical compositions used in manufacturing the batteries provide different output voltages.
Nov 21, 2023 13:38:09 #
Nov 21, 2023 14:40:29 #
chrissybabe
Loc: New Zealand
BebuLamar wrote:
Because the chemistry is different. Alkaline batteries nominal 1.5V per cell. Zinc Air battery 1.4V. NiMh or NiCad 1.2V. Lithium ion 3.7V, lead acid 2V etc..
Don't forget lithium ion at 3.6v and lithium polymer at 3.7v (or vice versa I forget). This one will cause you more problems than any of the ones above.
Nov 21, 2023 14:50:42 #
BebuLamar wrote:
Because the chemistry is different. Alkaline batteries nominal 1.5V per cell. Zinc Air battery 1.4V. NiMh or NiCad 1.2V. Lithium ion 3.7V, lead acid 2V etc..
I have one camera that does not like NiMh batteries at all, it prefers Alkaline.
Nov 21, 2023 15:16:03 #
chrissybabe
Loc: New Zealand
Longshadow wrote:
I have one camera that does not like NiMh batteries at all, it prefers Alkaline.
This should not come as a surprise. Every battery driven item is designed for a certain chemistry AND certain voltage range. The difference between 1.2v and 1.5v is quite large. Usually a battery driven item has a certain minimum voltage it will still work at and 1.2v is almost certainly below the cutoff for the 1.5v battery so it probably thinks the battery is actually flat.
Nov 21, 2023 15:18:25 #
BebuLamar wrote:
Because the chemistry is different. Alkaline batteries nominal 1.5V per cell. Zinc Air battery 1.4V. NiMh or NiCad 1.2V. Lithium ion 3.7V, lead acid 2V etc..
Yeah, that's always struck me as odd. Everything is designed for 1.5v, but rechargeables don't quite reach that. Still, things work.
Nov 21, 2023 15:24:02 #
chrissybabe wrote:
This should not come as a surprise. Every battery driven item is designed for a certain chemistry AND certain voltage range. The difference between 1.2v and 1.5v is quite large. Usually a battery driven item has a certain minimum voltage it will still work at and 1.2v is almost certainly below the cutoff for the 1.5v battery so it probably thinks the battery is actually flat.
It does....
Couple of shots, and that's it.
Nov 21, 2023 15:27:16 #
jerryc41 wrote:
Yeah, that's always struck me as odd. Everything is designed for 1.5v, but rechargeables don't quite reach that. Still, things work.
Probably because those circuits were designed to work down to 2.5 volts (maybe less - batteries in series).
Nov 21, 2023 15:34:17 #
chrissybabe
Loc: New Zealand
Longshadow wrote:
It does....
Couple of shots, and that's it.
Couple of shots, and that's it.
That's because a fully charged battery with no load sits at a certain voltage until it is first used. Then that initial voltage drops very quickly to a flatter normal voltage which is will probably maintain for most of its life until requiring charging again. So the initial voltage might just fit in at the bottom end of the cutoff voltage for the higher rated battery, take two shots which 'burns off' that initial charge thus dropping it below the cutoff voltage and it stops working.
That is why you shouldn't use a digital voltmeter to check the voltage level of a battery because the high input impedance doesn't cause the initial no load voltage to drop to the real one. Put a load across the battery and then measure the voltage.
You must surely know this ?
Nov 21, 2023 15:40:49 #
Longshadow wrote:
Probably because those circuits were designed to work down to 2.5 volts (maybe less - batteries in series).
I use 1.2v batteries in everything wants 1.5v, and they all seem to work.
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