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Old Jan 8, 2007, 3:29 PM   #1
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Currently I'm using the sony charger that came with the camera, which take 6hrs to charge a pair of 2500 Amh batteries.

I'm looking for a charger that can charge 4 batteries at a time that can be plugged to the wall without a cord. Preferably a universal charger. I don't like bulky units.

Thanks for any advice.
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Old Jan 13, 2007, 1:51 AM   #2
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I went through 3 sets of brand new 2700 mAh wall charger/batteries and could barely get 10 mins of video out of the best pair in my camera... 20% of the batteries were stone dead out of the box, wouldn't even be recognized by the charger. They were made in China, "[no]Power2000." Returned them all.

Alkalines ran at least 30mins of video, for comparison.

Then I bought from here:
http://ripvan100.com/

First read about them here on this site.
http://www.steves-digicams.com/lightning4000.html

All I can say is OMG :G GET THEM!
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Old Jan 13, 2007, 8:23 AM   #3
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I've read great things about the Titanium TG2800 from Amondotech.

After reading the description of the Lightning 4000, it charges cells in pairs rather than individually. The TG2800 charges cells individually. I would recommend a charger with individual charging circuits so as not to under or over charge one of the cells in the pair.





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Old Jan 13, 2007, 2:15 PM   #4
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Actually, there is a specific reason that it charges in pairs and that site's forum, one of the most informative I've seen on the web, tell you why...

Most products use AAs in even pairs and pair charging/discharging best equalizes the voltage and capacity between two batteries. This is due to a "resistive" tendency for NiMh to charge more when it's near its peak capacity, or drain more, when it's low capacity at 1.1v. Then what happens is that the the one batt that's at it's "resistive" level will then push additional charging, or additional drain, to the other battery. Over a few cycles two somewhat mismatched batteries become "conditioned" and "paired" together so that charge and burn evenly together... and they should stay paired.

On the contrary, using an independent charger, if one battery is weaker than the other, then camera will only last as long as the weaker, and the strong will become weaker since it doesn't get full charge/drain cycles.

Of course, it could all be marketing hype, but it makes a lot sense to me from my experience with rechargeables.
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Old Jan 13, 2007, 8:06 PM   #5
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Hello Reppans,

I like the Lighting 4000N and think is does a good job, however, their "hype" is not correct.

The best way to balance cells is to individually charge them. Charging in parallel has some limitations. One of which is that a weak cell stays weak, while the strong cell gets overcharged and damaged enoughto bring it down to the weak cells capacity.

If you would like to study the "balancing" characteristics of cells in parallel, try this test. Find a flashlight or something that uses a single cell. Now take two cells, one of them empty and the other one fully charged. Hook them together in parallel and let them sit for 4 hours.

You would expect both cells to end up at 50%, but while the voltage will tend to equalize, the capacities will not. In 4 hours only a small amount of capacity will be transfered to the empty cell.

To finish the test, power your flashlight (orother single cell device)up and note the run time. The cell that started full will run for a "normal" amount of time, where the empty cell will hardly run for any time at all.

In order to "balance" cells while parallel charging, you need to have an extended top off charge. The Lightning 4000N does this pretty well, and if you do a discharge first, it will bring both cells to a reasonably equal full charge. However, if one cell goes weak on you, you will be in trouble.

Tom
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Old Jan 13, 2007, 10:32 PM   #6
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Hi SilverFox...

That's an interesting point of view but there's a certainly more to the story. RipVan has mention that for batteries running in parallel, where there is significantly different states of charge, it will take a number of charge/discharge cycles to bring the two batts into an equilbrium. And that you should always use a multimeter to pair 2 like AAs when possible.

Then secondly, in my own experience (but, admittedly, I'm no expert) with Li-ions, the batteries do seem to charge from 0 to 80% capacity very quickly, say an hour, and then take another hour to go from 80% to 100%. (I've also read that this was the nature of the Li-ion.)

That means to me that these rechargeables do seem to have this resistive nature to hit full capacity. So you if you put in one batt at 0% and the other at 80%, in parallel, it would seem that one would hit 80% and the other 100% after an hour. Then discharge and recharge again they would be even closer in capacity, and so on.

Then, when you consider how these batts discharge, in parallel, I would have believed that a camera would just draw juice from the path of least resistance, ie the more powerful of the 2 batts. So if one batt is weak and the other strong, I would have thought that the stronger one would have to pull more than its own weight, support the weaker one, and drain faster.... in effect a battery "tag team".

Finally, it's been a very long time, if ever, that I've impressed with the performance of a battery: alkaline, Li-ion or NiMh, and I've been using rechargeables for over 10 years, (Li-ion, Ni-Cads and NiMh). But I just tested two 2700 AAs from RipVan in an A710IS, in video mode.

I got 3.5 hours or 15 gigs of video recording (640x480, mix of 30/15 fps) from 2 AAs.... by comparison, alkalines last just over 30mins in the same test.

I'm not saying it's because of parallel charging, I'm just saying I think this guy knows what he's doing and is pairing an excellent charger with superb batteries - Sanyo.

Just before I bought these, I returned (twice!!) some garbage individual bank charger 2700s (made in China [no]Power2000s) I bought at J&R Music/Computer... couldn't get 20mins of video from any combination of these crap batts. Not saying its because of individual bank charging, the quality of the batts just sucked.

ps, there seemed to be quite a few people on RipVan's site that came over from LaCrosse and Maha individual bank chargers as well.

Well after all that, I'm a believer now and I'm not going back...
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Old Jan 14, 2007, 9:54 AM   #7
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I checked out RipVan's site and it does appear to be an excellent charger IF you only use(andonly plan to use)devices that use 2 or 4 cells.I have several devices(flashlights, radios)that use 3 AA cells, and I'll use my independent circuit chargers for these devices.

Based on the information and customertestimonials, I bought a Lightning 4000 ($25shipped). I'll use it as a travel charger for mycameras thatuse 2 or 4 AA cells. I'm going on a 2 week tripin a couple months, and the RipVan will most likely go with me.I also have a Sony Travel Charger with independent circuits.

My favorite individual circuit chargeris the MH-C800S. It cool charges cells and does a wonderful job.
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Old Jan 14, 2007, 11:07 AM   #8
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Good luck with it Coppertrail...

Keep in mind that the underlying battery is probably more than half the equation, and I've experienced huge differences in quality between brands, and age of cells... I just about fell off my chair when I saw what those new Sanyos can do.

Agree on the odd number of batteries issue. However, I seem to have avoided toys that need 3 batts, but have a lot that take 1 batt. Of course, it is much easier to pair up onesies than threesies...
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Old Jan 14, 2007, 11:26 AM   #9
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Agreed, I use Sanyo and Powerex 2700 mAh cells in my cameras when I'm traveling or taking lots of photos at a 1 day event.

I use Eneloops for general use when my cams are sitting on the shelf for 1-2 weeks at a time.
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