Battery Quality

[Robert M Wright]

Alex -

Do you mean literally explode? Does that actually happen?

Do the Chinese batteries ever push to much power at a camcorder?

[Doug Boze]

This sounds awfully apocryphal, and batteries never "push" anything. They are a reservoir of potential energy. If they can't supply the current demands of the load, they could overheat, but the voltage drop would probably convince the camera that the battery was dead before anything serious happened. As I noted in my tests, the Chinese job had a lower charged voltage and higher disharged voltage than the others. This shows a higher internal resistance. The XL-2 is rated at 7.2 watts full load at 7.2 VDC. That's one fat ampere of current, a lot for any battery to supply continuously. That's like a 120 watt light bulb on 120 V.

[Alex Dolgin]

Originally Posted by Robert M Wright

Alex -

Do you mean literally explode? Does that actually happen?

Do the Chinese batteries ever push to much power at a camcorder?

These (catastrophic events) do not happen too often, I would not worry about it. The poor quality packs usually do not deliver rated capacity, and/or discharge cycles.
You hear about the fires in the news once in a while, may be once a year or so. A few years ago there was famous Sony recall, safety related. Within last 12 months there was Dell laptop packs recall. Some of the problems are related to the defective protection circuitry, some to the actual cell defects. When it does happen, it is bad. Li is inherently dangerous flammable chemistry, that is why all the extra protection circuit goes into every LiIon pack.

[Robert M Wright]

Thank you both. The prospect of blowing $10 on a battery that winds up not holding a charge doesn't faze me (big deal, throw it away). But if it destroys a valuable camera, that's a whole different matter entirely.

[Doug Boze]

I've never heard of any such thing. I know Sony stopped making their BP-L90 v-mount battery because fo airline restrictions on lithium (yeah, you're gonna make a hydrogen bomb), but seriously, never a story about batteries (apart from car batteries) exploding. Can you give an example?

[Alex Dolgin]

Originally Posted by Doug Boze

I've never heard of any such thing. I know Sony stopped making their BP-L90 v-mount battery because fo airline restrictions on lithium (yeah, you're gonna make a hydrogen bomb), but seriously, never a story about batteries (apart from car batteries) exploding. Can you give an example?

Here is the latest one, about 2 months old:

"Dell recalls batteries from 22,000 laptops

December 16, 2005

BOSTON (Reuters) - Dell Inc. <DELL.O> said on Friday that it is recalling batteries installed in some laptop computers it sold in the United States over the past year, citing an overheating problem with potential to pose a fire risk.

Consumers can contact Dell at (866)-342-0011 or http://www.dellbatteryprogram.com/ to see if their laptops are among those affected by the recall.

No injuries have been reported, though Dell said it has learned of three incidents that caused damage to the furniture and personal effects of its customers.

The batteries were installed in some 22,000 laptops that Dell sold from October 2004 to October 2005.

The company shipped more than 5.6 million computers in the United States during the third quarter of this year, according to an estimate from market research firm IDC. "

[Robert M Wright]

That's heartwarming.

[Doug Boze]

Unfortunately, it doesn't say what causes the overheating, what kind of batteries are involved, etc. I don't see how this relates to the current discussion.

[Robert M Wright]

Well, I'm glad it's not about camcorder batteries, and I don't own a Dell ...LOL.

[Johan Forssblad]

Originally Posted by Robert M Wright

Well, I'm glad it's not about camcorder batteries, and I don't own a Dell ...LOL.

Robert, not that particular case. But do you know there are restrictions onboard aircrafts how many or how big Li-Ion camera battery you are allowed to bring with you or ship onboard aircrafts? Only about 8 g Li is allowed! However, this means quite a big 90 Wh 14.4 V battery is right under the limit for shipment.
The fines are very heavy if you break this and it gets attention.

That's because these batteries are potentially unstable if they are dropped or heats up. Anton Bauer has written about this here:

http://www.antonbauer.com/li_ion_trans_faqs.htm

"Lithium-ion rechargeable batteries whose equivalent lithium content exceeds 8 g. per battery must be shipped as a "Class 9 miscellaneous hazardous material"."

"Passengers can also carry no more than two lithium ion batteries that contain more than 8 gr. of equivalent lithium content per battery."

So, there is a safety issue with Li-Ion batteries and it does not only apply to cheap batteries.

Not very long ago Apple Computer had to make an emergency stop and put in NiMh batteries in their laptops despite the boxes and brochures were already printed saying it contained Li-Ion batteries! Still they have issues about recalling battery batches.

So, don't drop them and make sure they cannot become short circuited if you lay them around in bags etc. /Johan

[Johan Forssblad]

Originally Posted by Doug Boze

I just ordered one of these "BP-945" 6000 mAh batteries off eBay. We'll see how it does.

Hey, you will get a hint how you could easily test all rechargable batteries? Buy one advanced charger for RC-models, car or aircraft with electric motor. It costs probably around USD 150 or so.

Mine is called Triton and will charge and discharge NiCd, NiMH, Pb and Li-Ion cells or blocks in many various sizes. It has a great display showing time, voltage, Ah and more. It runs from a car battery or you need a 12 V power supply.

You can program a charging cycle for a certain charge and another discharge, for instance 500 mA charge and 1000 mA discharge. It will discharge until it reaches a presetable voltage and then alarm and stop. Then you could easily see how many mAh you got out of it. Much better than running down your expensive video head.

I use this charger all the time to check my cells. At least twice a year or so I put them to test then I write the actual capacity on the battery. Very nice when I have plenty of R6 cells. I just combine some of them with similar real capacity when I need power to something.

When talking different batteries I still not have enough experience from the Li-Ion types.

Many modern NiMH cells, for instance R6 size, are overrated and will not give you their advertized capacity. My Panasonics, for instance, perform about 1750 mAh but are labeled min. 1900 mAh. They are two years old.

About NiCd cells: I had R20 Berec cells from 1984 which I have used to run a Nagra taperecorder. Despite much abuse they still gave 85 % of its rated capacity after 20 years!! That I would say are quality batteries! But hear now, I bought them used at that time!!! Unfortunately my kids have used the cells in their torches forgetting to turn it off so they killed them recently.

Other unknown or cheap brands have worked fine for years, Sunrise especially. And I have had quality brands (GP, Varta) where one cell in a pack of 6 gave up within half a year without any bad handling.

Unfortunately, the more cells there are in a package, the more likely the chance is one cell will fail early. So these modern hermetic sealed batteries are bad to us because you cannot exchange that faulty cell, at least not easily. Instead you have to dispose the whole pack.

I have also seen that some exercise is good for the battery, especially the NiCd. It can gain capacity. Battery charging is scientific these days.

Good luck everybody with your battery! /Johan