Can these GP 2700 be fake?

HI.
I've just bought GP 2700mah.
I have 30-min fast GP charger for years already which charges with 3.4Amps (approx).
I've charged those 2700, and very surprisingly charge time took only some 8-10 minutes. As a result batteries worked only tiny amount of time (10% of what they should)

I know this charger is very picky. It refuses to charge half of my old (1600s,1800's) cells. It measures internal resistence, and also has -delta v algorythm. It also has 4 independant cell places, and temperature measures.

I'm trying to think what could be the problem. The GP cells look pretty real.
I once bought noname fake cells, they were surprisingly light. Those GP seems all right.

I thought that these newer 2700 might have larger internal resistance, and maybe unsuitable for fast charge. I have some other old ni-mh cells with too high internal resistance. But these just won't charge at all (red blink).And I can approximate internal resistance by ampermeter. (Old ni-mh cells can't give out more than 3-4 Amps when i put ampermeter for a split second. These 2700 give out ~20Amps which seems very good.

So What could be the problem?
I'm gonna try to charge them in cheap 200ma constant current charger, for some 15 hours and see what happens.

Sometimes happens with any nimh

Try recharging, should be ok then

A false positive before.

What do you mean by "try recharging" ?
_you mean charge them and drain many times ,and see if they get better?

Junglemike, with 200mAh you should charge your 2700 mAh cells approximately 20 h.

Anders

After initial short charge, take them out of the charger, then put them straight back in.

You should then find that they will accept a normal charge.

I find it works every time, when the nimhs's short charge, on occasion.

I had problems with my 2500 mAh false peaking at higher rates until I did the 1/10C 16 hour forming charge. Maybe easier for you to just restart them a couple of times. They should charge fine after a few cycles. Good luck.

Kevin