how much Volt is a fully chargered NiMH

[Tjin]

hi there,

I just got a new little travel charger and it shuts down when the voltage in the NiMH batteries hit 1.34 Volts. Doesn't look full to me, since my other chargers will charger to a higher voltage. So can anybody tell me how full a NiMH 1.34Volts is?

 

[Mr Happy]

It's really difficult to tell how full a NiMH cell is from its voltage.

However, most NiMH cells read higher than 1.4 V right after they come off the charger. It sounds as if your charger may not be applying a full charge.

Are the batteries new and good quality?

 

[Tjin]

well the battery where salvaged from a cordless phone. The are like 600Mah, but they have worked very well. They had been laying around unused for a month or two. But the charger went off after like 5 minutes, so that didn't look right.

 

[FILIPPO]

BC6 stop the cycle when they reach 1,5V...

 

[ltiu]

hi there,

I just got a new little travel charger and it shuts down when the voltage in the NiMH batteries hit 1.34 Volts. Doesn't look full to me, since my other chargers will charger to a higher voltage. So can anybody tell me how full a NiMH 1.34Volts is?

My Kodak overnight charger that came with my Kodak Pre-charged shuts down at 1.34 volts too.

 

[Marduke]

Best get a proper smart charger

 

[mpf]

eneloop charging specs show upto 1.7V at 0deg C when fully charged

http://www.eneloop.info/uploads/media/Datasheet_-_HR-3UTG_01.pdf

matthew

 

[Lynx_Arc]

1.34 is low for a full charge on NIMH... I would suggest perhaps the meter you are using may not be accurate. I have a rayovac 1 hour charger a BC-900 and a 15 minute Energizer charger that all do 1.4v or more on a full charge.

 

[Tjin]

Best get a proper smart charger

I have proper chargers, but they are to big for traveling and backpacking.

 

[SilverFox]

Hello Tjin,

Are you sure your cells are NiMh?

When I charge NiCd cells on a charger that cuts off at a peak voltage, they come off the charger in the 1.34 - 1.39 volt range...

Tom

 

[jtr1962]

NiMH is typically about 1.47V hot off the charger, in some cases as high as 1.51V or 1.52V. Nicad is generally about a tenth of a volt less than that (1.37V typically, 1.41V in exceptional cases).

 

[etc]

It's really difficult to tell how full a NiMH cell is from its voltage.

However, most NiMH cells read higher than 1.4 V right after they come off the charger. It sounds as if your charger may not be applying a full charge.

Are the batteries new and good quality?

I noticed that there is a correlation between voltage and remaining capacity. That is, when a NiMH cell reads 1.19V or so, in my case it will no longer power the devices I have.

If voltage is a bad way to tell, when how do you tell?

 

[Mr Happy]

Voltage is a bad way to tell, and there is not really a perfect way that you can tell. You need either to keep track of how much the cells have been used since their last charge, or to use a battery tester like the ZTS to get a rough estimate.

However, voltage does give some clues. A fully discharged NiMH cell can be relied on to read 1.2 V. If a cell reads less than 1.2 V after resting it is almost certainly damaged, or at least very old and worn out. If it reads more than 1.2 V it has some charge in it, but it's hard to say how much. Somewhere in the 1.28 V - 1.34 V range is about half full, and from 1.35 V up to 1.45 V is getting on for fully charged. You can be rather certain that above 1.45 V the cell is fully charged.