I was impatient and now I'm paying the price. I should have known better. My wife was kind enough to buy me an Olympus D450Z a few months ago. It ate alkaline batteries like popcorn, just like everyone says.

I panicked and bought the NiMH batteries in-town, rather than doing it right and ordering a MAHA charger/Nexcells from Thomas Distributing. So, now I have 8 x 1250 mA NiMH "AA" Eveready ACCU batteries, and a handy little charger. Great little batteries, and the rebate made them really cheap. BUT, now we're planning a trip to Europe--how do I charge the "AA" NiMH batteries? I know MAHA offers a Euro 220V charging coord for $11.90 for their chargers--I'm guessing it includes a small transformer to step-down the voltage from 220V to 110V, but can it also change the 50 HZ to 60 HZ? Or do the NiMH "AA" batteries simply not care about the frequency of the energy during the recharge? Can I just use my Eveready ACCU charger, buy a small transformer for the voltage, buy a plug adaptor, and ignore the 50/60 Hz issue?

I called Eveready, and they said the charger is only designed for the US. Big help, I told them next time it's MAHA for me. Great web-site, lots of helpful answers, thanks!

-- Aras Suziedelis (aras@alum.mit.edu), April 24, 2000

Answers

You can probably get away with a 240/220->120 transformer. Battery charging circuits aren't usually too particular about AC frequency, since after the transformer steps the voltage down the diode bridge changes the AC into pulsating DC and everything else in the circuit usually runs off capacitively filtered DC. You might notice a bit of hum from the transformer, but as long as it doesn't heat up it shouldn't be a problem. Have a good look at your charger, it might be rated 50/60 cycles or hertz. Most transformers are rated 50/60hz anymore anyway. But, if you were trying to run a 60hz motorized clock or something off 50hz you might notice a slight timekeeping problem... :-) AC motors are usually synchronus, and in this country, run at a multiple of 60hz, like 1800 or 3600 RPM.

You could bypass the whole issue with a charger that runs off DC that could be plugged into a rental car, or simply buy a solar charger and hope for good weather or strong room lighting. I think Thomas sells both. [chargers, not sunshine... :-) ]

Some(most? many?) hotels abroad and cruise lines offer a 120VAC shaver outlet in the bathroom, this should be just fine for a charger. Why not check with the hotel in advance?

-- Gerald M. Payne (gmp@francomm.com), April 24, 2000.

Aras:
The 50/60 hz is not a big factor. The step down will work without converting the frequency.
Call ahead. Most European hotels have 110 volt outlets in the bathrooms for "american shavers" that will work perfectly fine for rechargers (although it says for shavers only - the chargers actually pull less current than the shavers. They only want to make sure people don't plug hair dryers into them).
I spend a lot of time in Europe and have used these outlets for this purpose quite a bit.

Des

-- Dan Desjardins (dan.desjardins@avstarnews.com), April 24, 2000.

Using the outlets in the bathroom is a good idea.. another one is to buy one of those travel kits that have all the standard plugs for most countries... they usually come with a step-down transformer 220 to 110v...

-- Keat Lim (keatlim@my-deja.com), April 24, 2000.

Go to www.greenbateries.com.. You will be amazed at the deal they will give you PLUS their intelligent charger switches AUTOMATICALLY betwenn 120VAC and 220VAC. It can also charge NiCd batteries and is microprocessor controlled.

-- Romuald J. Krukowski (rjkruk@hotmail.com), May 19, 2000.

Buy a charger in Europe. A cheap one will cost you $10 top.

-- (Gareth.Watkins@bbc.co.uk), December 28, 2001.