New AAA NiMHs - charge em up or discharge them first?

Batteries and Chargers Rechargeable Batteries
1

I’m trying to be more particular with how I handle my rechargeable batteries to ensure I maximize their usefulness. My order of AAA LSD Turnigy’s arrived yesterday (that were recommended by brother BLF’rs :crown: ) and I’m wondering if I should just charge them up or should I run a discharge cycle first? FWIW I’m using a Tenergy T6280 smart charger:

2

I suggest to to a full discharge first. Then 3 full cycles of charge/discharge

3

and if you do not have a hobby charger what is the best way to discharge other than installing them and running them down?

ken

4

Use them (discharge) until they reach 0.9 volt… sometimes is easy to see. Some flashights (well regulated ones) will give full power until the batteries got down to 0,9v.

5

I’ve read that you can drain an Nimh as low as you want, and I’ve read that it’s harmful to the cell . Is there an absolute answer on this ?

Thanks

6

My observations are that pre LSD crap Ni-Mhs didn’t like to be discharged too much, but that might be just that they were crap to begin with.
On the other hand I even reverse charged (thanks to parasitic drain in 4xAA t6 headlamp) pair of new LSDs lately and they don’t show any damage - work the same. But they were only mildly reversed, like –0.03V for a month.

I think that a good advice is not letting them below 1,2 rest voltage - very easy to do with LSD, but hard to achieve with the old hi-cap cells like 2500 or 2700 that just drain themselves completely empty on their own.

7

Thank You

Bruce

8

One more thing.
For longevity of cells, it’s more important not to charge (or discharge) with unnecessarily high currents and store ’em in rather discharged condition.
Also keeping them cool while charging and not letting them overcharge is very important.
I personally never charge AA with more than 0,5A and the slower, the better and also better charge.

9

Thanks again

I’ve got a new set of eneloops about a day into a break in with a new Powerex MH-C 9000 charger. I have to be gone tonight and would hate to stop the process with over 24hr into it. Would it be safe to leave it run while I’m gone overnight ?

Bruce

10

wow, more than 24 hours to discharge AAA cells? Mine (different charger) only took a couple hours max… :ghost:

11

It’s four new AA’s and the charger is on break in mode. It takes an enormous amount of time, not sure if it’s worth it.

12

Break in involves discharge, charge, and resting. The maha 9000 takes them through several cycles. The resting breaks throughout the cycle keep the cell at optimal temp and let the cells settle before continuing. This Breakin gets the juices flowing, like sending your cell to the gym. It is good to do for cells that have been sitting around unused for six months. The break in time on my Maha takes about 2 1/2 days.
Yes you can safely leave your NiMh’s in the MaHa 9000 while you are not there.

13

Thank You !