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alf Apr 12, 2003 2:56 AM

10 days without mains power?
can anyone recommend my best options for powering a Fuji finepix 4900Z without any mains power to recharge batteries.

I know I could buy some spare batteries but I guess I would need at the very least 10, which starts getting expensive.

Is there anyway of using disposable batteries somehow?

lg Apr 13, 2003 1:04 AM

Do you have access to an auto with a 12vdc power outlet? If so, buy one of the Maha chargers from Thomas Distributing and purchase an inexpensive CLA for a couple of bucks. Then, just charge them from the car battery.

If you don't have ANY power source, then you'll probably need 3 sets of 1800maH NiMh batteries/day. Be sure to charge all of them right before you leave for your 10 day excursion-- they can lose much of their charge in 30 days.

NHL Apr 13, 2003 8:49 AM

I've noticed that RadioShack now carry the ICP solar charger in their stores... You'll need plenty of daylight though!

jbailey Apr 14, 2003 5:51 AM

Both of the above suggestions would work great assuming you have a car and/or sunshine. Actually the Rayovac 1 hour also uses 12VDC and has a car cord.

Another idea if the two above won't work for you would be to buy a bulk pack of AA Alkalines. I can get a package of 48 Toshiba AA's for about $10 locally. The alkalines won't last as long, but a set of 48 should last you ten days.

That solar charger looks like a great idea, but if I bought one it would rain for the whole 10 days!

voxmagna Apr 14, 2003 6:52 AM

What about wind power? those small boat generators can put out high watts in wind. The problem with any alternative energy, is both the uncertain intermittent nature of the source and the design of the regulator/charging system to cope with it. Because NimH can absorb short duration high charge currents, wind and sun could be ideal with the right regulator design.

20-40 watts is flea power for a wind generator. No vehicle - do you have a bike? 1 hour riding around could easy charge a pack. Wind up battery charger like radios in Iraq!, Water turbine on the household water main? Peltier units on the gas cooker- mains or propane, Mamod steam engine with generator, overwindings on chainsaw/brushcutter magneto, keep fit: hook up a gene to your bike or excercise machine - the possibilities are endless!

NHL Apr 14, 2003 5:48 PM


Believe it! All we need is one for the NiMh AA's... (or make an adapter!) :lol: :lol: :lol:

voxmagna Apr 15, 2003 11:59 AM

NHL...Hey that's good. You only need just enough charge to power the cam, get the zoom out, (charge the flash), frame the shot, save to MD, and shut down the cam.

Years ago I had a dynamo flash, so a dyno-digicam wind and shoot could be quite innovative - where are they?

They could've done a better ad: lonely female, in broken car with hood up - there's ergs of juice in that car bat for a phone. Now, female on horse or camel in the middle of nowhere...! The colour co-ordination says a lot about the target market.

alf Apr 16, 2003 1:53 PM

Some good suggestions.

I like the idea of the hand generator.

The other limitations I have are that I cant guarantee that I will have access to a vehicle (hiking and mountain biking), and also the camera I have (Fuji Finepix 4900Z) uses its own shape battery, so AAA, AA etc. batteries wont fit.

Does anyone know of a battery adapter that could be used?

voxmagna Apr 16, 2003 4:57 PM

Hi, my intended post just got lost when my pc went to sleep - so this won't be polished!

Now we know what you're up to, I'd suggest 2 options: A solar panel on the top/back of a rucksack and dynamo on the mountain bike. Your cam uses a special NP80 3.7 volt battery. If your cam has dc in, you could probably use 3 or 4 re-chargeable NiMh, but I'm guessing you probably have a spare NP80.

You need to regulate the power source to prevent too much current charging the battery. I've never seen a NP80. If it has 2 wires only then those will be connected to the battery. If it's got more then others may be connected to charge sensing circuits. I can only advise further if you have wires connected direct to the battery, with no electronics in between.

Charge the batteries fully in their charger. Then connect the cam battery to a diode (preferably Schottky type) then to a bulb and then the cycle dynamo. More about the bulb later.

If the bulb lights when dynamo not turning, then the diode is the wrong way round. The bulb needs to be chosen using small car/cycle bulbs by experiment. When the dynamo is running at max output, measure the current into the fully charged battery. Select a bulb which is glowing dimly and gives about 100ma charge. If you get no current, check the polarity of the dynamo output. Now try a cam battery which is pretty flat. The bulb will glow brightly (showing the bat. is flat) but you should check the current isn't more than about 1 amp. Just guessing, but try small bulbs rated at 1-2 watts (volts is not important).

Now for the solar panel. Most panels come with a diode built in, so you probably won't need that, just the bulb - and get the polarity right, positive goes to positive! In bright sunlight repeat what I said for the dynamo and select the right size bulb.

To do this properly would need a circuit designed, this is pretty crude advice, but if you're careful to check the battery does not get extremely hot (overcharge) you haven't got a lot to lose. The worst is you fry a battery if you're belting down mountains all day, or hiking in Iraq.

Under no circmstances connect this power source to your cam socket - only charge batteries!!

NHL...nobody's mentioned the pendulum dynamo you strap to your leg!

Good luck - VOX. PS I've not actually tried this!

NHL Apr 16, 2003 9:20 PM


Does anyone know of a battery adapter that could be used?
It seems like the easiest way for you may be to make an adapter cable from a rechargeable flashlight to your camera AC adapter input (and forget about charging the camera's battery when it goes out) :lol: :lol: :lol:

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