NiMH battery recharge

[Tioleco]

I have several 3.6V batteries ( type 18650 ) used in notebooks that have a low voltage between 1V and 2V ; can I still recharge them?

[eccerr0r]

Re: NiMH battery recharge

You can always try, just recharge them normally for a few minutes. If it doesn't go up to near normal voltage quickly, it's probably a dead pack.

I've seen a few of my NiMH packs drop to 0 after sitting for years and it will charge back up... but usually won't hold charge long.

[budm]

Re: NiMH battery recharge

NiMH battery Voltage is 1.2V not 3.6V.

[Tioleco]

Re: NiMH battery recharge

NiMH battery Voltage is 1.2V not 3.6V.

I was mistaken , in really is Li-ion battery 3.7v.

[sam_sam_sam]

Re: NiMH battery recharge

Be very careful charging this type battery with a battery voltage that low

One note charge one battery at a time and watch the + and - on the battery to the charger

DO NOT charge them as a pack if the battery protection circuit is any good at all it might not charge the battery pack

You can try this but your maximum amperage should not exceed 500 ( or lower would be better ) milliamperes until your battery voltage goes higher than 3.2 volts once the battery voltage is 3.2 volts

( without the charger hook up to the battery wait for five minutes and see if the battery voltage start dropping if it does to the voltage that you started with do not use them )

the maximum charging amperage should not exceed 1 amp

DO NOT leave them unattended while there voltage is below 3.2 what you are watching for is the temperature of the battery and should not exceed 100*F
If it does I would not use them

Success rate is maybe 50% to get beyond this point

I would still keep an eye on them for temperature until they reach 4.2 volts because sometimes when start to reach around 3.8 or so they start heating up

This type of results I would question weather or not to use them

If you get beyond this point and your battery have charged up 4.2 volts and have not raised in temperature very much

Success rate is maybe 30% to get beyond this point

Then I would recommend the following

Charge them and discharge a few times and see if you get the same results in amp hours if you do then you might have some good useful life left in but make sure that they are not heating up while charging them or discharging them

Success rate is maybe 20% to get beyond this point

I hope this helps you

Please be safe while you are charging these type of batteries

[petehall347]

Re: NiMH battery recharge

with my experiences with lithium iron just get new ones . they are not worth the risk to me . having to pick up smoking ones and throw outdoors made me give up with them .
i do however believe if you have the time and equipment you can charge some up and use them again . secret is to make them work often and keep charged up but not overcharged . they need to be used .

[sam_sam_sam]

Re: NiMH battery recharge

with my experiences with lithium iron just get new ones . they are not worth the risk to me . having to pick up smoking ones and throw outdoors made me give up with them .
i do however believe if you have the time and equipment you can charge some up and use them again . secret is to make them work often and keep charged up but not overcharged . they need to be used .

I have one comment and that is this

I would add that if you are going to buy new batteries only use Panasonic ,Sanyo, LG ,Samsung batteries ( A123 use to be a very good brand but when they went bankrupt and someone bought the name there quality is not what it used to be buyer beware)

I would not recommend using any other brand of batteries ( there some exceptions to this but it is hard to tell which one are good quality and what is not )

Here is one exception and that is the Black Web brand battery power pack that Walmart sells there quality is pretty decent for the price that you are paying for ( one note 26650 not 18650 )

The marking on them says either 2X or 7X more power other ones are not as good of quality

but I do have a caution about their batteries and that the material housing case is very thin and if you do not turn down the welding current you will blow a hole in battery metal case ( you can solder them the solder will take to it pretty easily if you 60/40 solder

Most of the time the no name brands claim that there milliamperes rate is unbelievable high and quality is very low and not worth the money that you think your saving

[Stefan Payne]

Re: NiMH battery recharge

I have several 3.6V batteries ( type 18650 ) used in notebooks that have a low voltage between 1V and 2V ; can I still recharge them?

They are probably NOT NiMH but Lio Batterys...

For example:
https://www.nkon.nl/de/sony-us18650v...gaAqsvEALw_wcB