Archive for June, 2008

Warning – Strength 2950 Ni-MH batteries

Sunday, June 8th, 2008

Just a quick word of caution for everybody considering the purchase and use of Strength 2950 mAh Ni-MH rechargable batteries. We have been using a couple of these AA Mignon R6 batteries for about a year now, and just the other day it happened to us, that two of the batteries were actually damaged during recharge.

As usual, the batteries got very hot in the charger (we’re using the Ansmann POWERline4), but after a while the LEDs for two of the batteries were neither blinking (indicating “charging”) nor constantly lit (indication “charged”) but off. I looked at the batteries in question, and they, too, were quite hot, showing visible damages to the outer mantle. Not good – and actually quite scary!

Damaged Strength 2950 Ni-MH battery
Mark Zanzig/zettpress

On one battery the mantle had just torn open, looking wrinkled instead of the usually smooth surface; the other battery showed even signs of burns in addition to the wrinkled surface! Jeez.

We used to use these batteries mostly with our flashes for wedding photography and news reporting. As the batteries also get quite hot after a couple of flashes, we have immediately stopped using these batteries. Our Canon Speedlites are too expensive to be actually ruined by some faulty battery that got too hot inside the flash. Even more important is the reliability of the batteries. They seem to have lost their stamina recently, so we had to exchange them quite often during a shoot if we wanted to be sure that a flash would actually fire.

For the time being, we have returned to using classical photo batteries for our flashes, especiallly when shooting weddings and news.