topic Re: Is there a piece of equipment that can accurately measure the mAH capacity of a Canon camera bat in General Discussion

Is there a piece of equipment that can accurately measure the mAH capacity of a Canon camera battery

henryrgold — Tue, 29 Mar 2016 21:32:36 GMT

In the radio control airplane field, there are devices that get connected to a battery and will accurately measure the mAH capacity by discharging through a known resistance and periodically measuring the voltage. A calculation is done of the total mAH, then you will know if the battery is still good. Is there such a device for Canon camera batteries (like the BP-511A)?

Re: Is there a piece of equipment that can accurately measure the mAH capacity of a Canon camera bat

cicopo — Wed, 30 Mar 2016 00:28:45 GMT

I have the type of charger you're talking about & I guess I could (if I wanted to) rig it up to do that but I've never seen anyone talk about one for camera batteries. I use mine to charge my LiPo's (which power my R/C models). I have only used it once to see just how much I had discharged a battery after a flight. I know lots of people do use them that way but the way I fly I don't run my batteries down enough to worry about how close I am to the cut off point.

The only time I've ever load tested my camera batteries was years ago with the batteries used in the older 1 series ( Pro) bodies which are old technoligy.

Re: Is there a piece of equipment that can accurately measure the mAH capacity of a Canon camera bat

Waddizzle — Wed, 30 Mar 2016 01:00:03 GMT

@henryrgold wrote:
In the radio control airplane field, there are devices that get connected to a battery and will accurately measure the mAH capacity by discharging through a known resistance and periodically measuring the voltage. A calculation is done of the total mAH, then you will know if the battery is still good. Is there such a device for Canon camera batteries (like the BP-511A)?

The devices that forcibly discharge a battery like that tend to destroy the battery in the process. Batteries are designed to provide just so much current over a given unit of time. Subjecting the battery to provide that amount of current in 1% of the time, or less, is most often destructive to the battery that is "under test." Heat is the enemy.

Re: Is there a piece of equipment that can accurately measure the mAH capacity of a Canon camera bat

cicopo — Wed, 30 Mar 2016 02:33:31 GMT

Without finding the manual for my charger I know that it does several common types of battery but I don't know if it will do the BP 511 BUT it's designed to do it WITHOUT straining the battery being tested. It doesn't punish the battery being tested (drained) & in return isn't cheap either. R/C er's who fly EFD (Electric Ducted Fan) Jets rely heavily on their batteries & are hard on them due to the heavy load but these chargers can keep them in good order for a few seasons of use.

Re: Is there a piece of equipment that can accurately measure the mAH capacity of a Canon camera bat

ScottyP — Wed, 30 Mar 2016 03:05:08 GMT

Call B&H or Adorama and ask if they can test batteries for a small charge (pun intended).

But seriously, if such a tester in fact exists, it would not likely make sense to actually buy your own when the camera batteries are only $35-$40 or so.

Re: Is there a piece of equipment that can accurately measure the mAH capacity of a Canon camera bat

RobertTheFat — Wed, 30 Mar 2016 11:24:46 GMT

@cicopo wrote:
Without finding the manual for my charger I know that it does several common types of battery but I don't know if it will do the BP 511 BUT it's designed to do it WITHOUT straining the battery being tested. It doesn't punish the battery being tested (drained) & in return isn't cheap either. R/C er's who fly EFD (Electric Ducted Fan) Jets rely heavily on their batteries & are hard on them due to the heavy load but these chargers can keep them in good order for a few seasons of use.

It's probably just my ignorance, but this thread puzzles me a bit. I know that some chargers have an option to drain a battery and then subject it to one or more intense charging cycles; but the object is to try to jar a failing battery back to normal functionality, not to test its ability to hold a charge. The idea of risking damage to a battery that isn't showing serious signs of failure seems counterintuitive. Is it really ever considered a sensible course of action?

Re: Is there a piece of equipment that can accurately measure the mAH capacity of a Canon camera bat

cicopo — Wed, 30 Mar 2016 13:26:27 GMT

I'll try to explain in relatively easy to understand terms but this is off the top of my head.

The type of charger we (Radio control people) use doesn't try to load test the battery like an auto mechanic does. They are computerized & we input the following info so the charger knows exactly what it's hooked up to. Battery chemistry, (LiPo in my case which runs 3.7 V per cell), and how many cells it has (3S means 3 cells in series) which is an 11.1 Volt battery. Our batteries have both a positive & negative terminal & a safe (sometimes very questionable) discharge rate which can be relatively low to quite high & that affects price. If you fly an electric powered plane or helicopter that runs at full throttle most of it's flight you need high discharge rate batteries. All of this info is on the label so you set the charger accordingly. The batteries also have another terminal known as the balance terminal & it connects to each individual cell & the charger constantly monitors the voltage of each cell & not the total voltage. If one cell is charging faster than the others the charger loads that cell to bring it down to what the other cells are at & then starts charging all of them again & this cycle repeats over & over again until the battery is fully charged OR the charger alarm goes off because it can't balance all the cells. We set the charger to know the desired battery charge in milliamps & a charging rate from low to fast, and fast can shorten battery life if used all the time. The ideal charge rate is .8 to 1 X the milliamp rating BUT high discharge rated batteries can be charged using the first figure in the rating, (IE 50 Amp rate can be charged at 5 times the Milliamp rating). Our batteries have the voltage, Ma rating & safe discharge rating on the labels. Some come in hard shell cases (usually used in boats or vehicles where weight isn't so important) or soft packs which are more or less like vinyl & easily damaged in a crash but weigh less.

Conversly the same charger can measure how much power is left in the battery AFTER use (as in how much more flight time did you have). It doesn't apply a heavy load but one within the rated constant discharge rate you've set & drains the battery down to the cut off point our components can still work properly at. We can learn just how long you can fly a given model before hitting the limit on the battery where you may loose control. We then set our flight timers so we prepare to land well before that limit is hit. The charger can also fully charge a battery & then do a discharge cycle to test how well the battery chemisrty is doing it's job, and again tell us the battery looses it's charge too fast to be reliable. We need reliable batteries when flying. A bad cell can cause a very expensive crash.

Re: Is there a piece of equipment that can accurately measure the mAH capacity of a Canon camera bat

Waddizzle — Wed, 30 Mar 2016 17:00:30 GMT

"It's probably just my ignorance, but this thread puzzles me a bit. I know that some chargers have an option to drain a battery and then subject it to one or more intense charging cycles; but the object is to try to jar a failing battery back to normal functionality, not to test its ability to hold a charge. The idea of risking damage to a battery that isn't showing serious signs of failure seems counterintuitive. Is it really ever considered a sensible course of action?"

Nope, that's your common sense kicking in.

I have seen the military implement regular testing regimes on the backup batteries for their building systems. These systems would include their critical HVAC systems, Access Control, Fire Alarm, and CCTV systems, etc. They want to be sure that the battery backups can last for their rated service times, which is typically between 24 and 72 hours depending upon the system.

I'm talking about pretty sizeable battery arrays, each rated by the dozens of amp-hours, not millliamp-hours. You can also find these types of systems in broadcast studios, and other communication systems. I have seen entire floors in some of NYC's skyscrapers dedicated to just battery arrays.

Those types of tests date back decades, back to the days when lead-acid batteries were common. Those monsters could take being violent discharged, and they needed regular testing and exercising to ensure their performace. But, with the introduction of Ni-Cad batteries, which cannot tolerate high discharge rates, the charging systems have been improved to the point where the chargers themselves can actually self-test the batteries every couple of minutes, and report back to a remote central station the state of the batteries.

Re: Is there a piece of equipment that can accurately measure the mAH capacity of a Canon camera bat

Waddizzle — Wed, 30 Mar 2016 17:02:23 GMT

"But seriously, if such a tester in fact exists, it would not likely make sense to actually buy your own when the camera batteries are only $35-$40 or so."

I think that is the best answer that you will get. it ain't worth the expense.

Re: Is there a piece of equipment that can accurately measure the mAH capacity of a Canon camera bat

cicopo — Wed, 30 Mar 2016 20:39:59 GMT

I totally agree with that too. When in doubt buy a battery.

On another note my first real job was working for Bell's division that installed the equipment in telephone offices. We either upgraded old equipment or filled new buildings with the equipment, wired & tested it & turned it over to Bell when it was ready for them to put it on line. Telephone offices (back then, not sure about now) had huge battery back up systems & the batteries in some buildings were the size of smaller SUV's of today.

Re: Is there a piece of equipment that can accurately measure the mAH capacity of a Canon camera bat

Waddizzle — Wed, 30 Mar 2016 23:30:55 GMT

"Telephone offices (back then, not sure about now) had huge battery back up systems & the batteries in some buildings were the size of smaller SUV's of today."

I hate to say it, but there systems that are a whole lot bigger than that. Like I said, I have seen entire floors of a skyscraper converted into one big battery room. The television studios in NYC are good examples of it. They have systems that can deliver three phases of 440 volts AC, with each phase delivering 1000 amps.

And, they can deliver that much power for up to 1 hour, which is just long enough for the emergency generators to kick in. They allow time for the primary generator to fail, until it rolls over to the secondary, until it rolls over to the stand-by. Those generators are huge engines. When they fail to start, they go through a 5 minute cycle that purges the fuel laden air that has built up inside of it. Three consecutive failures initiated a roll over to the next generator.

They wanted to be blackout proof, and keep their multiple satellite feeds on line. I've set them up before. Testing the systems are a challenge because knocking them off the air could cost the networks tens of thousands of dollars per minute, due to lost ad revenue. We literally watched TV and waited until a local commercial, like promoting the local news team, was broadcast.

Re: Is there a piece of equipment that can accurately measure the mAH capacity of a Canon camera bat

cicopo — Wed, 30 Mar 2016 23:59:20 GMT

Bell is a little different in that the systems were 48 Volt DC & like your systems they had generators as the first stage of back up & if they failed to keep up the batteries were next BUT if it went to the batteries mobile generators (Tractor Trailer mounted) were instantly on their way for additional back up. I have worked in their power bays (it's where they put me on day 1 for several months) & we had 80,000 Amp circuits. The power bays were all connected by 1/2 inch thick copper bars 4 inches wide & layered as needed to handle the amperage. We had to cover them up with special tarps whenever we worked is those areas & the rule was if you drop something don't reach for it. One guy dropped a 36 inch long wrench that turned into a very big spark when it fell but there wasn't a wrench left to hit the floor. Back then (60's) land lines were an essential service our government depended on & I worked in the building servicing the government several times.

Re: Is there a piece of equipment that can accurately measure the mAH capacity of a Canon camera bat

Waddizzle — Thu, 31 Mar 2016 00:34:15 GMT

The battery backups were just a stop gap, until the generators would kick in. I have seen some big ones in my time, with turbine driven air intakes. They literally had a jet engine driving the generator's turbine blades.

I have never done phones, but I have done high voltage radar in the 1970s. I have seen vacuum tubes the size of basketballs, and others which had to be water cooled in tanks of de-ionized water. The tanks were as big as a large refrigerator. The "coaxial cable" on the output was actually 36" pipe with a coaxial 18" conducting pipe inside of it. Output power to the antenna array was 5 megawatts.

That system was capable of detecting objects in low Earth orbits, up to 1000 miles in altitude. Today, we use satellites.

[EDIT] We once had a squirrel take a stroll on the output transformer one day. All that was left of it was a fluffy tail. Have you ever seen a plasma form between the plates of a vacuum tube before? I have. The plates were the size of a playing card, a couple of inches apart..

Oh, yeah. The main transmitter room for the radar was the size of basketball court. There were grounded copper sheets on the floor, like carpet runners, where you were supposed to walk when it was powered up. One day one of the output tubes, with the glowing plasma, failed. Lightning bolts were jumping out of the racks onto the copper flooring. It was a scene straight out of a James Bond movie; sparks, flames, and lightning bolts. It was my job to go in and shut it off. I used a wooden handled hammer to flip the four critical toggle switches.

Re: Is there a piece of equipment that can accurately measure the mAH capacity of a Canon camera bat

cicopo — Thu, 31 Mar 2016 13:19:38 GMT

That must have been "exciting"! Bet you didn't want to do that on a regular basis. Might have made a great video though.

Re: Is there a piece of equipment that can accurately measure the mAH capacity of a Canon camera bat

henryrgold — Wed, 06 Apr 2016 12:15:02 GMT

Thanks everyone for the discussion so far. I asked the question, not about huge room-sized batteries, or even the battery packs that are used in r/c airplanes. This is about the 1000 to 2000 mAH battery used in the Canon cameras. A capacity tester is useful to determine if the battery is deteriorating. If one battery cost is $10 - $20, it would be worth it to have a tester in the $50 - $100 range, if you need a collection of batteries to keep your equipment running. I have seen articles on the internet about home-grown capacity testers along with discharge graphs that are produced, which clearly show the difference between a "weak" battery, and a "strong" battery, based on the shape of the discharge curve. You don't know how good a battery is, when you buy it. There is a large variation in the quality of the basic cells inside the pack. I was surprised to see, in the discharge curves, some batteries had only 1/3 the capacity they were labeled as!

I am just looking for a more scientific approach to this area, as opposed to just keeping a bagful of spares. If you are a member of a photography club, such a capacity tester could be shared among the members.

Re: Is there a piece of equipment that can accurately measure the mAH capacity of a Canon camera bat

cicopo — Wed, 06 Apr 2016 13:04:08 GMT

I'm in Canada & prices are higher than in the US but I think Europe is even higher but the charger I use wasn't too much over $100 when I bought it. The trick would be making the necessary adapters for the batteries since they don't come with lead wires & a plug. R/C batteries have both the balancing plug & the power plug but camera batteries in general have terminals set down into the protective case to prevent shorting out when there's metal (like a coin) in the same pocket the battery is. To date I've never seen adapters to do that & I follow several photography forums, BUT they may exist.