NiMH Rechargeable AA battery. | Problem (4v for 1 cell!) | Relfex Charging?

Batteries and Chargers Chargers
1

I found some Rechargeable NiMH AA batteries that I lost the original charger for.

I put 1 of the AA's on my Duratrax ICE to charge it.
Set it to NiMH 1cell 2500mAh and 0.1Amp charge/0.1amp discharge using Automatic mode.

My charger started voltage at almost 4v then over like 30-60sec dropped to every voltage between that and 1.5v.
The shot back up to 3.5v and started dropping again to about 1.5v.

Seems to be repeating in a cycle, decreasing the highest voltage each time; i.e. 4v to 1.5v, 3.5v to 1.5v, 3.0v to 1.5v, 2.5v to 1.5v, 2.0v to 1.5v.

Temps are remaining constant about 72F-73F over 5minutes.

The battery itself reads "NH15-AA 1.2v NiMH HR6"

I tested the battery with a DMM and it reads the same that the charger is reading.

Is this normal behavior?

I somehow posted this on the Sub forum for battery reviews. I moved it after I noticed, sorry about that.

2

No mate that’s not good, stop using the battery.
It means the inner case has split, and that holds the chemical for the charge of the battery, if it splits or breaks in any way there’s basically no fixing it, just be glad it hasn’t ruptured on you as it charged and spilt it’s innards over your charger.

3

Sound like you have it set to Lithium Ion not NiMh.

4

It looks like this might be "Reflex Charging"

Can anyone confirm if it is Reflex Charging and that I am not going to die from charging my batteries?

Screenshot from manual:

Picture of my screen:

A few min later:

Any idea if that's what it is?

UPDATE:

The charger finished charging my battery. Said "End: Delta-Peak" when it completed.

End voltage is 1.36v which is decent for a 1.2v NiMH.

Still looking for a reason why it's charging like this.

5

Going to move this over to the "Chargers" Forum.

I think it is more fitting there.

6

1.36 seems low. I have a bunch of NiMH chargers and the batteries usually come off at 1.43 - 1.48.

7

But why Capacity only 30mAh :quest:

8

each battery varies by design, i have some non lsd duracells that terminate at 1.64V, and eneloops usually at 1.52V and some rayvoac at 1.48V

i find after sitting off the charger 1.36V resting voltage means the cell is about full.
it can take an hour to a few hrs to get to resting voltage

9

Those batteries nominal voltage is 1.2v and I think brand new fully charged is supposed to be 1.4v.the capacity is way off because I started the charging after it was stopped, it was already partially charged. was that reflex or repeak charging going on? And not a damaged battery? this forum isn't phone friendly, sorry for the terrible formatting.