nimh battery cells.

[ady]

been looking at some nimh individual battery cells that are 1.2v each, i guess this is its voltage when flat?? what would the voltage be when charged?

[dragonmaster_1]

Re: nimh battery cells.

That is the voltage of single cells
If you put 10 in a pack that gives you a 12v pack

[ady]

Re: nimh battery cells.

cheers tony, so a charged 12v pack is about 14volts? so would a charge cell be around 1.4volts?

[cliveb]

Re: nimh battery cells.

Tony you have mail in your messages

[botmad]

Re: nimh battery cells.

between 1.28 and 1.4 a good new cell

[ady]

Re: nimh battery cells.

ok cheers.

[dragonmaster_1]

Re: nimh battery cells.

Hi Clive
nothing in my Messages
But found pump in boot of car

[geoff]

Re: nimh battery cells.

between 1.28 and 1.4 a good new cell

Pete, if I had a new cell that only came up to 1.28 it would be going straight back to where I bought it!!

I would expect a new fully charged good quality cell to come off the charger at around 1.55 dropping to no less than 1.4

(Just noticed... 1000 posts! )

[cliveb]

Re: nimh battery cells.

Hi Tony new message should be in your in box.

[botmad]

Re: nimh battery cells.

Sorry Geoff i didnt finish my post ::::


New cells should be between 1.4 and 1.6........ :P

[m2xt]

Re: nimh battery cells.

Not sure where you guys get your NiMH cells from but as a rule you should not charge above 1.5V per cell so no idea how you get 1.6V. After charging thise voltage will decay and settle out at something between 1.28 and 1.35 in my experience (off load) although I can't say I have checked every pack and manufacturers may differ. On load, the cell terminal voltage falls due to the internal resistance by an amount proptional to the current drawn. You should not discharge a cell ideally below 1V, 0.9V worse case.

[geoff]

Re: nimh battery cells.

Paul, I'm not doubting your figures in the slightest, from experience using 20 x Vapex 4300 cells, my Astroflight 112D chargers tend to 'peak' at around 31V - 31.7V (1.55V - 1.58V per cell) After a couple of hours (off load) I can normaly measure a pack voltage of at least 28V (1.4V per cell) hence my numbers above. I grant you I'm accepting the reading from the charge's own display for the final voltage (however accurate that may be!) but I can confirm the (off load) pack voltage using my ukascal Fluke 115 meter. I will check the final voltage next time with the meter and post the results.

[botmad]

Re: nimh battery cells.

same pack as above only 12v after charging at around 4amps no load measures about 16v .... hence 1.6

[m2xt]

Re: nimh battery cells.

The voltage soon after charging is higher than it will be some days later. I have just checked some Sanyo and Ansmann RC packs that were all charged 3 weeks ago and all showed between 1.29 and 1.31V / cell. I did a discharge test on three packs and all gave the correct capacity. If you check the voltage immediately after charging, it will of course be higher and that again depends on whether you fast charge or not.

So my answer to Ady is it depends on when you make the measurement after charging and not doubting what others are finding, depends on the manufacturer. I would not return a pack just because it only has 1.28V / cell, I would do a discharge test. In fact I had a batch of RC packs that still showed over 1.3V/cell yet could only deliver about 30% of their rated capacity.