Can you ruin NiMH batteries by recharging them too often?

[Mucho]

I know it was best to fully discharge NiCad batteries before recharging them, does this also apply to to Nickel Metal Hydride batteries?

 

[mauiblue]

I thought this is a good link about the care and maintenance of NIMH batteries. I know that any type of battery has a certain "cycle life" (charging and discharging) but if you don't abuse them and overly discharge them or even over charge them, they should last a while.

 

[corkyg]

Originally posted by: Mucho
I know it was best to fully discharge NiCad batteries before recharging them, does this also apply to to Nickel Metal Hydride batteries?

No it does not. NiMH batteries do not take a chargin set. However, like any rechargeable, they have a lifespan. For a laptop battery - two to three years is good service.

 

[Aluvus]

It is never better to fully discharge batteries before charging them; this applies to NiCd, NiMH, Li-Ion, and any other consumer rechargables.

Don't go charging them ever few minutes. But also don't feel bad about recharging them when they are, say, 10% drained.

Batteries are rated for a particular number of partial discharge cycles and a particular number of full discharge cycles; the number of partial discharges they can handle is much greater. It is much better for them to be discharged a little bit and then recharged than to be discharged almost completely and then recharged.

 

[SSNSeawolf]

Originally posted by: Aluvus
It is never better to fully discharge batteries before charging them; this applies to NiCd, NiMH, Li-Ion, and any other consumer rechargables.

Not so. I play quite a bit of Airsoft with battery-powered guns. Proper chargers for our batteries will always fully discharge a battery before charging it. Otherwise the battery will lose its "memory" over time.

Furthermore, (though I'm not sure this applies to Li-Ion), a good charger will trickle-charge a battery near its full charge, though I'm not sure why.

I'm sure Dan of Dan's Data would have a good and entertaining answer on the matter.

 

[Aluvus]

Originally posted by: SSNSeawolf
Not so. I play quite a bit of Airsoft with battery-powered guns. Proper chargers for our batteries will always fully discharge a battery before charging it. Otherwise the battery will lose its "memory" over time.

Which is really, really hard on the battery but helps make the most out of each recharge. It's done for RC cars as well, for the same reason. That reason is not, however, "memory" of any kind, and in point of fact consumer batteries are unlikely to ever demonstrate real memory effect. Satellites orbiting the Earth in space, yes; Satellites made by Toshiba that you can type notes into, no.

Furthermore, (though I'm not sure this applies to Li-Ion), a good charger will trickle-charge a battery near its full charge, though I'm not sure why.

To get the most possible charge into it without setting it on fire. A slower charge won't heat up the battery as much (and NiMH certainly warm up as they are charged) and makes it easier to pick out the "fully charged" point without going past it and risking damage to the battery.

 

[lenjack]

LI-Ion batteries can be charged to the brim at all times without suffering. They have no memory effect, and in fact can be left on tne charger all the time with no ill effects. Not true for other battery types.

 

[Juno]

Originally posted by: corkyg

Originally posted by: Mucho
I know it was best to fully discharge NiCad batteries before recharging them, does this also apply to to Nickel Metal Hydride batteries?

No it does not. NiMH batteries do not take a chargin set. However, like any rechargeable, they have a lifespan. For a laptop battery - two to three years is good service.

it's like i can charge nimh batteries 24/7??? i recharge my nimh AA batteries for wireless mouse.

 

[MrX8503]

If you want good NiMh batteries get the 2500mah energizer with the 15min charger built in fan.

The charger cools the battery with a fan, which prolongs the life of the batteries. Also the charger doesnt charge based on a timer like most chargers, it stops charging when the batteries are full.

 

[Juno]

Originally posted by: MrX8503
If you want good NiMh batteries get the 2500mah energizer with the 15min charger built in fan.

The charger cools the battery with a fan, which prolongs the life of the batteries. Also the charger doesnt charge based on a timer like most chargers, it stops charging when the batteries are full.

i have a duracell one hour charger with 8 AA and 4 AAA nimh batteries. (2050 mAh.)

are they good? i might want to buy a better charger with better batteries.

 

[Aluvus]

Originally posted by: MrX8503
If you want good NiMh batteries get the 2500mah energizer with the 15min charger built in fan.

The charger cools the battery with a fan, which prolongs the life of the batteries. Also the charger doesnt charge based on a timer like most chargers, it stops charging when the batteries are full.

It would do much more to prolong the life of the batteries to just buy a slower charger.

No NiMH or NiCd charger I've seen relies on a timer, because that doesn't work with batteries of different capacities and ages.

 

[roemer21]

It would do much more to prolong the life of the batteries to just buy a slower charger.

No NiMH or NiCd charger I've seen relies on a timer, because that doesn't work with batteries of different capacities and ages.

I would have to agree with Aluvus here. From experience, this seemed to prolong the lifespan of my own battery by about 4-6 months over my brothers identacle battery. Find a slower charger for prolonged life.