[SOLVED] Recharging NiMH batterys 2150mAh

The battery charger i have is an Energizer Recharge Model: CHFC2

It says in the manual that is can charge double AA NiMH up to 2650mAh

The battery I am using are brand named Lenmar R2G , Nickel Metal Hydride , 1.2 volts at 2150mAh

Will these batterys explode? or get damage? if I leave them in the Energizer Recharger more then the estimated charging time , which is 6hrs

Do you have to fully discharge NiMh batteries before Recharging them again?

If I only Recharge them half way or less then full , will these damage the NiMh batteries?

Yes, You can use this charger for charging 2150mAh batteries. Normally chargers have auto shutoff feature. Charger automatically stop charging batteries once it fully charged. Some charger have built in timer also i.e it will stop charging batteries after a given time. My charger stop charging batteries after 12hours. Even if your charger doesn't have these feature, it should be okay, if you overcharge for few hours. Battery may explode if you overcharge for a very long time & battery get heated too much. You should completely discharge your batteries in a month before charging. It will increase battery life.

My Energizer charger is model CHDC-CA and has an output of 2.8V at 360mA. It came with 2300mAh Ni-MH AA cells.
It is simply a timer that operates for about 8 hours and cooks 600mA Ni-Cads and starts all over again and cooks Ni-MH cells if the power fails then comes back on.

If you completely discharge Ni-Cad or Ni-MH cells in series then the weakest one gets destroyed because after it goes dead the remaining discharging cells charges it in reverse. So NEVER discharge batteries.

Here's the datasheet for the OP's charger: https://data.energizer.com/PDFs/chfc2.pdf

Notice the section on "shutoff mechanism." It is designed for NiMH and automatically shuts off when charge is complete. It is not simply a timer.

John

It is designed for NiMH and automatically shuts off when charge is complete.

Click to expand...

Are you sure the Energizer Recharge Model: CHFC2 , won't damage the NiMH batteries if i leave them to charge overnight?

If I charge them half way, will this damage NiMH batteries? because the next time I full charge them it will only charge them half way because the NiMH cells have been damaged

If you completely discharge Ni-Cad or Ni-MH cells in series then the weakest one gets destroyed because after it goes dead the remaining discharging cells charges it in reverse. So NEVER discharge batteries.

Click to expand...

How do you discharge NiMH batteries the correct way? to get the longest life out of the batteries?

Query #1:


Have you done that? Note: The charger automatically turns off, if a peak is not reached within a predefined time. There is also a trickle-charge aspect. Check your manual.

Query #2:

How will you know when you have charged half-way? Can you share that information with the rest of us? Generally speaking, rechargeable batteries should be charged fully each time they are recharged. One thing to consider is the number of cycles. NiCd's allow a lot of charge-discharge cycles; NiMH typically allow far fewer cycles. Why would you want to reduce that number even further?

Have you checked out "Battery University?" ( )

John

ParkerMike said:

Are you sure the Energizer Recharge Model: CHFC2 , won't damage the NiMH batteries if i leave them to charge overnight?

Click to expand...

No, because the charging is finished and the trickle-charge current is very low.

If I charge them half way, will this damage NiMH batteries? because the next time I full charge them it will only charge them half way because the NiMH cells have been damaged

Click to expand...

The charger detects when the cells are fully charged then stops charging.

How do you discharge NiMH batteries the correct way? to get the longest life out of the batteries?

Click to expand...

It is WRONG to discharge Ni-MH cells. Old Ni-Cad cells developed a "memory" which reduced their capacity and voltage if they were not discharged but not Ni-MH cells.