Is it OK to recharge partially charged NiMH?

[Kelvrick]

I have some nimh's for my digital camera and I'm going out with a group of friends tomorrow night. The thing is, none of them are fully charged, and I don't wanna run out of power before the end of the night. You have to discharge Nicd's before you recharge them again, but what about nimhs?

Do I have to leave my digital camera on to drain the batteries?

 

[amdskip]

Hmmmm, I know on cordless drills that you should completely drain the battery before replacing it or else it will not charge as full next time. YMMV on this one

 

[gopunk]

basically yes. that is the key benefit of nimh over nicad.

 

[Kelvrick]

Originally posted by: gopunk
basically no. that is the key benefit of nimh over nicad.

So... No to the question of me having to leave my camera on, right? Not, its not ok to recharge partially charged nimhs?

 

[Jerboy]

You can charge them up without discharging them.

 

[gopunk]

sorry i meant to say yes. you don't have to discharge before charging, the memory effect is not noticeable for nimh.

 

[Kelvrick]

Ok, cool. Thanks everyone.

<== goes to plug in recharger.

 

[MWink]

It won't hurt them but it is a good idea to totally discharge them once in a while. Also, if you recharge after a partial discharge they won't have as high a capacity as if you had totally discharged them.

 

[spanky]

my recharger drains the batteries before it charges them back up

 

[Kelvrick]

Originally posted by: spankyOO7
my recharger drains the batteries before it charges them back up

Damn you. What I get for buying a cheap $10 recharger.

 

[luvya]

Do you guys know what kind of battery are using in today's cell phone?

 

[dude]

NiMH. Most of them being 3.6 volts.

 

[Jerboy]

Originally posted by: luvya
Do you guys know what kind of battery are using in today's cell phone?

Nickel Metal Hydride or Lithium Ion.



spankyOO7 wrote:

my recharger drains the batteries before it charges them back up

That is called battery conditioner. It was considered worthwhile in high end chargers in 80's when NiCd technology was still improving and had most of the rechargeable battery market.

 

[ElFenix]

i still condition.

<---- old fashioned


and my NiMH batteries don't seem to lose charge as quickly as most people's.

 

[luvya]

Ok, I just found out my cell phone use Li-ion battery......how is it compare against Nimh or Nicd? Do I need to discharge before recharging?

 

[Shaka]

I read that batteries should only be conditioned when they seem to be losing their potency. Conditioning too frequently is worse for the longevity of the battery than conditioning infrequently is.

But that's what I read somewhere.

 

[Thegonagle]

Yes, it's fine.

It's even fine on Ni-Cd batteries, as long as you don't make a habit of it. (The "memory effect" of Ni-Cds is reversible after a few full charge-discharge cycles.)

 

[Thegonagle]

Originally posted by: luvya
Ok, I just found out my cell phone use Li-ion battery......how is it compare against Nimh or Nicd? Do I need to discharge before recharging?

AFAIK, They're fairly similar to Ni-MH in most respects, except they only last about 18-36 months max, and they're very lightweight compared to other rechargeable battery types.

EDIT: And they have a fair amount of "shelf life," unlike Ni-MH.

 

[MWink]

AFAIK, They're fairly similar to Ni-MH in most respects, except they only last about 18-36 months max, and they're very lightweight compared to other rechargeable battery types.

EDIT: And they have a fair amount of "shelf life," unlike Ni-MH.

I think that's quite inaccurate. NIMH are much more similar to NICD. Li-Ion are very very different from the other two. For starters they are a different voltage per cell (1.2 for NICD/NIMH, 3.6 for LI-Ion). Li-Ion are very light (so are NICD) and NIMH are very heavy. As for the 18-36 months max... WRONG!!! I have a Li-Ion battery in my 6 year old Dell Latitude XPi and to my knowledge it has never been replaced. It still holds a good charge and runs the laptop 1:45 min. Another difference is NICD/NIMH can be charged many different ways safely. Li-Ion batteries have to be charged very carefully or they can explode/catch fire.

 

[Thegonagle]

Well dammit! Now I've got to go find myself some accurate info on the subject.

BTW, I was literally quite drunk (and full of fried chicken from Bobby and Steve's) when I wrote that.