Cheap Batteries

[Motorsports Photo]

Just got back from a trip to Walmart. While making my way from the motor oil aisle to the milk aisle, I stopped at the photo aisle and found BP-511/512 batteries for $20 EACH

I thought that was a darn good price so I bought two. I did need one to replace a generic 512 that wont keep a charge, even though its only 2 years old.

I bought one of these batteries before and found it to perform well, even in cold weather.

-Pete

[ron chappel]

I'm having excelent success with my cheapie but it's only a couple of months old.Others have said they go just as well/last just as long as canons.I think the two years you got out of the old one seems to be about waht to expect from any brand :cry:

[pradeep1]

Just got back from a trip to Walmart. While making my way from the motor oil aisle to the milk aisle, I stopped at the photo aisle and found BP-511/512 batteries for $20 EACH

I thought that was a darn good price so I bought two. I did need one to replace a generic 512 that wont keep a charge, even though its only 2 years old.

I bought one of these batteries before and found it to perform well, even in cold weather.

-Pete

That's a very good price for cheapies. I need to mosey on down to Walmart one of these days again.

[Motorsports Photo]

I think the two years you got out of the old one seems to be about waht to expect from any brand :cry:

To compare: The original BP-511 I got with my D30 is only slightly less strong now than it was when new. The generic 512 was stronger than the 511 when new, but now its junk. I bought the 512 after a year of shooting with the original Canon 511, and I only bought it because I thought it might be a good idea. Until then I had no problem with shooting for a day without charging.

ANyway now I'm stocked up!

-Pete

[PhotosGuy]

According to this site...
http://www.batteryuniversity.com/parttwo-34.htm

" Aging of lithium-ion is an issue that is often ignored. lithium-based batteries have a lifetime of 2-3 years. The clock starts ticking as soon as the battery comes off the manufacturing line. The capacity loss manifests itself in increased internal resistance caused by oxidation. Eventually, the cell resistance will reach a point where the pack can no longer deliver the stored energy, although the battery may still contain ample charge. Increasing internal resistance is common to cobalt-based lithium-ion, a chemistry that is found in laptops and cell phones. The lower energy dense manganese-based lithium-ion, also known as spinel, maintains the internal resistance through its life but loses capacity due to chemical decompositions. "

[robertwgross]

So, these lithium ion BP-511 batteries... are they cobalt-based or manganese-based?

---Bob Gross---

[ixyeos]

They should be lithium -ion


cheapest original BP-511 1100mAh
$29.8 free shipping !!!
http://sonyhp.com


cheapest generic $11.9
http://sterlingtek.com

[robertwgross]

The question was: are these lithium-ion batteries cobalt-based or manganese-based?

---Bob Gross---

[theoldmoose]

Dunno, but I would take what you read at Battery University with a grain of salt. The guy has something to sell you (pricey battery reconditioning equipment) and promotes himself as a non-lettered self-made battery chemistry expert. When he started blabbing on about Ni-Cad memory effect he lost my respect right there. That is one of the most persistant battery myths, ever.

I have (or have had) several Li-Ion based devices that worked for five years or more, and never needed a new battery. A couple of cell phones were 'topped off' and partially discharged daily throughout their life. The phones broke long before the batteries ever wore out. A laptop that I have that is over four years old tends to stay plugged in almost constantly, but has never failed to give me a full charge's worth of use when I take it traveling or to meetings/seminars.

The Li-Ion lifetime data I've seen is based on total discharge/recharge cycles, and is typically in excess of 1000 or more. Partial cycles are OK, and only accumulatively count towards complete cycles (i.e. 3 33% partial cycles are roughly equivalent to one 100% cycle).

Disclaimer: I am not a lettered battery chemist myself, but at least I have some real (admittedly empirical) experience with Li-Ion cells, I've done some reasonably extensive reading on the subject (besides on the Internet) and I'm not trying to sell you anything.

Li-Ion technology (so far) beats anything else developed to date hands down for portable electronic technology. I say use it and be glad we have such a lightweight, powerful energy source (until the next great thing comes along).

BTW, for high current (low internal battery resistance) applications, like flashes, NiMH seems the current best choice.

[robertwgross]

... When he started blabbing on about Ni-Cad memory effect he lost my respect right there. That is one of the most persistant battery myths, ever.


Are you suggesting that there is no such thing as Ni-Cd "memory effect"?

You are entitled to your opinion, even if it is wrong.

Where I used to work, we had two engineers working on that for most of one year. Myth? I don't think so.

Unfortunately, some people get confused between Ni-Cd, NiMH, and Lithium-ion. They heard something once about Ni-Cd, and they think that applies to everything rechargeable.

----Bob Gross---

[theoldmoose]

... When he started blabbing on about Ni-Cad memory effect he lost my respect right there. That is one of the most persistant battery myths, ever.


Are you suggesting that there is no such thing as Ni-Cd "memory effect"?



Not according to the GE Battery Book, long the bible of the Ni-Cad industry. I still have my copy someplace in my basement archive -- I threw out all my other old data books long ago, but a few really useful ones still reside on my bookshelf.

[robertwgross]

Granted, people are not using so many Ni-Cd batteries now as they were a few years ago, but back then there were two groups of Ni-Cd users. Let's call those consumers and professionals.

The consumers were generally lacking in electronics aptitude, and they used simple rechargers with their Ni-Cd batteries. They generally paid little attention to charge rates or anything technical like that, and their batteries generally developed a reduced capacity after a time.

The professionals typically had somebody technically knowledgeable that was monitoring the batteries. They used good battery usage and recharge protocols, and they generally kept most of the capacity for a long time. But, that took time and money which consumers generally don't apply.

That is why some people claim to have good luck with Ni-Cd batteries, and others don't. In the consumer group, the "memory effect" caused lots of headaches for manufacturers who couldn't explain it to the consumers.

Fortunately, Lithium ion batteries don't have those kinds of problems.

Did we ever figure out whether our Lithium ion batteries (e.g. BP-511) are cobalt-based or manganese-based?

---Bob Gross---

[theoldmoose]

I would say that time (or knowledge, per se) had little to do with consumer's poor experiences with Ni-Cads. Rather, the idea that most folks, unless they are clued in to things better than what most marketers are willing to allow, will go for the low-cost solution.

You hit the nail pretty squarely on the head, Bob, when you stated that various consumer-level chargers were to blame. In general, they tended to over-charge the (usual) cheap Ni-Cads cells that had little or no tolerance for high temperatures (created either by environmental or charge/discharge cycles) and tended to vent at the drop of a hat (I guess that was better than simply rupturing, which a lot of the cheaper cells would have been likely to do, given the really cheap construction used to contain the cell and its goo -- scientific term, I swear :lol: ).

As far as the so-called 'memory effect', the typical case was usually a series string of cells contained in a pack, being charged by a 'quick' charger (5-7 hours) that may or may not have had an automatic timer. Even with an automatic timer, if you re-charged a partially discharged Ni-Cad pack, you invariably ended up overcharging the cells (or a household power failure would restart the time, re-charging an already topped-off pack). Usually one or more of the cells in the pack would vent a little to relieve the pressure in the cell. As the electrolyte thus starting drying out, the capacity of the cell would be lessened. Then, when the pack was discharged heavily, the weak cells would discharge first, and sometimes would actually be reversed by the surrounding cells in the pack. A few cycles like that, and chemical tendrils would grow in the cell, eventually shorting the plates. Now, you have an 8-cell pack that originally measured about 8 * 1.2V = 9.6V fully charged with say, a shorted cell, that measured only 7 * 1.2V = 8.4V fully charged. A Ni-Cad is considered discharged when its terminal voltage hits about 1V (actually not exactly, but let's assume that for the sake of illustration at the moment). So, an 8-cell pack would be considered discharged when the voltage hit about 8 Volts. You can see that a pack with a shorted cell would only show anything above 8 volts for only a short while, before the votage drops below 8 volts.

Thus, the so-called 'memory effect'. What's even worse, once you have a pack with a shorted cell, then subsequent charging divides the charging voltage over the remaining cells (remember Kirchoff's Law), thus over-charging the remaining cells every time the pack is re-charged. Total failure of the pack soon follows.

(BTW, The GE book describes another cell failure that happens to individual cells, they called 'voltage depletion'. If I recall correctly, this had something to do with oxygen combining on one of the cell plates (anode or cathode, I don't remember). It tended to look like 'memory effect', although GE indicated that failures of this type were very rare. I don't recall what they said triggered the condition, either.)

Now, how to work around these kinds of failure modes with Ni-Cad packs? Well, for starters, you might try a much more intelligent charger (more $$$), but there were limits to how smart you could make a charger that worked well when all the cells were in a series string, and you couldn't easily monitor individual cells. You could design a charger that you leave on the cells indefinitely, without harming the cells. That's called a normal charger, and it takes about 14 hours to charge a cell. Most consumers are too impatient for that. Even at that, leaving a cell on on 1/10-1/20C for extended periods might still damage the cell, so GE (and others) recommended a supply that would switch to a true trickle charge (about 5-10 ma) after a full normal (15 hour) charge cycle. You could design a fast charger that charges the cells in about 1 1/2 hours, but it required high-pressure, high-temperature cells (more $$$) and a thermistor in the pack (taped to one of the cells -- hopefully it is typical of the behavior of *all* the cells in that pack -- oops! you mean they aren't a closely matched set, like the ones used in orbiting spacecraft? Too bad...). You could hand-pick closely matched cells (by running charge/discharge curves, etc) and that is exactly what they do for spacecraft and other difficult to get at and repair systems. Last time I checked a matched set of cells for spacecraft applications ran about $50K. The AMSAT crowd decided it would be cheaper for them to buy several thousand dollars worth of cells and match them themselves, then sell the others surplus to their membership.

You will notice that most fast NiMH chargers handle individual cells, and ones that don't (the MAHA ones come to mind) have a little thermistor in a magnetic housing you need to stick on the side of the pack, so they stand a chance of detecting the sharp rise in temperature that occurs just as the cells reach fully charged state. They also detect a sharp rise in terminal voltage of the pack, so the thermistor is considered added insurance.

Li-Ion (thank goodness) is such a fussy technology (but good enough that folks are willing to buy a ton of it to fund advanced stuff like Li-Ion), that it *requires* individual cell monitoring and protection, and as such, that capability is built into every battery pack (or at least should be -- beware the $5 Li-Ion battery specials from street vendors in Thailand -- they have been known to short and explode in folks' cell phones -- something that has prompted Nokia and others to send out warning information for their customers, out of concern for their health). The plus side is that Li-Ion packs are kind of indestructible (as far as normal usage goes -- don't fold, spindle, or multilate -- you have been warned), the down side is that they do tend to be more expensive than other battery chemistries, but that is mostly made up for by great manufacturing volumes, and a good power/weight/size ratio.

And as far as the actual chemistry of Li-Ions, I had never heard that there were any such things as cobalt- vs manganese-based formulations, but there quite likely could be (and maybe a dozen different others, including pieces of Peeps, for all I know :lol:). If I get a chance, I'll look into that.

I do know, though, that a type of Li- cell to stay away from is the Li-Polymer, like the ones found in the Compaq/HP iPAQ. Unless you actively use your iPAQ every day, and keep it charged, you *must* do a cold-stop on it to disconnect the battery internally. Otherswise, in a matter of days, the iPAQ in suspend mode will run the Li-Polymer battery down flat, and ruin it. And the battery is not removeable. You will have to send the entire unit in for repair. We had several hundred of these in stock for a portable analyzer project, and found very quickly just how bad this problem could become. There is a reason why the iPAQs are shipped with the internal battery disconnected. So, if you can possibly avoid it, don't select equipment for occassional use that contain Li-Polymers.

[unclefester]

Re: Memory effect.

I have been involved in purchasing, testing, and using batteries for nearly 18 years, as part of my occupation in design electronics and computing.
I have designed and used battery chargers for Ni-Cad, Gel Cells, and Lead Acid. And taken the time to study battery characteristics, as they occur in ACTUAL USE. And then testing to verify the results.

And yes, I agree with the problem with multiple cells in a battery pack. The higher the charge current, the more likely that one cell or more cells will be more charged than the others, and hence mimic a "memory effect" because one cell may have high internal resistance.

Since most batteries used in portable electronic equipment are actaully batteru packs, the "memory effect" is very common, even amongst Li-Ion batteries (packs), such as the Sony Info-Lithium packs.

I am in the middle of some testing / "reconditioning" to bring some battery packs' life back up by discharging at a slow rate and re-charging in order to equalise the individual cells.

As for Lithium Polymer Batteries as used in cell phones, I follow the same "dual battery mode" that I use on Nicad and Ni-Mh. I always purchase two cellphone batteries for myself and staff, and run them flat before swapping them over over, so one is in use while the other is being charged.

An exception to the rule, 12 months ago I retrieved a cell phone & single battery (Li-Ion Poly) from an ex staff member, and was usually charged every night. In use it would be lucky to last a day in use. Putting it back into service as one of a pair, and doing the full discharge / charge routine, it is now giving several days on a charge, despite having been used extensively over the last 12 months.

And as for longevity, I maintain a UPS for a client, that still has its original Gel-Cell Batteries that were supplied with the UPS in 1988. ( note that is 1988, not 1998 )
Every year they get a full "power out" load test until the UPS indicates that there is 15 seconds of abttery power left. Then power is restored. Any anyone's book, 16 years is good for batteries that have a rated life of 3 to 5 years, but then its all about how they are looked after. http://photography-on-the.net/forum/images/icons/icon7.gif

[boBquincy]

Since someone mentioned the ultra-cheap cell phone batteries that have exploded:

We can't tell if a bargain battery is of the cheapest type or not just by looking at it. The $5 ones may be junk but some of the $20 ones may be as well. Canon batteries have presumably gone through at least some testing, have internal fuses, vents, etc. The bargain batteries, who knows?
I have a mid-priced BP-511 clone and it works well so far but after reading about cell phone batteries exploding I will stick with Canon batteries from now on.

If we save $30 on a battery and it destroys the camera it is no bargain. I realize Canon is overcharging (pun intended) to some extent but to me it seems like insurance.


boB

[elwood58]

In doing some research, I have been unable to find a single manufacturer who lists Manganese Oxide use in their batteries. Those manufacturers who actually listed in detail were 100% Cobalt Oxide.

Cheers

[robertwgross]

A few months ago, we read a notice here about non-Canon BP-511 batteries at two for $25, and I think a bunch of us jumped on that. I've been using my two new ones quite regularly.

---Bob Gross---

[MarkH]

My Power 2000 batteries are now over 14 months old and still providing better capacity than my Canon batteries. They seem to be better batteries at a cheaper price, I have no plans to ever buy Canon batteries again.