Canon 20D power indicator inop ERROR 99

[arpi]

Hi,

Today I experienced an error 99 in my new 20D. The cause of the error was a dead Li-ion battery that I was using for 2 days. After I replaced the battery with a spare one, everything cleared up. The problem is that my battery indicator in the top LCD always showed a fully charged battery, which was not correct. I am running firmware version 2.0 and I think the problem may be related to the firmwware version, I am not sure.

Has anybody with V2.0 firmware looked at the little LCD window and is able to see a battery indicator that shows low battery (when the battery is low)?

TX

[seangower]

I'm afraid to say it might not be firmware related.
I'm running V2.0 firmware on my 20D and my battery indicator shows a low icon towards the end of its charge.

[arpi]

thanks

[MrThanh]

I'm afraid to say it might not be firmware related.
I'm running V2.0 firmware on my 20D and my battery indicator shows a low icon towards the end of its charge.

ditto. I also have a cheap aftermarket battery, and that threw an error 99 when it was drained. the battery meter showed that it was still full though.

my 3 canon batteries are fine though and their levels show up ok on the top screen.

[arpi]

thanks.

It looks like it maybe a battery related problem then, I'll keep an eye.

The battery that was giving me the problem is the original battery that came with the 20D. I bought two more batteries (extra capacity 1550 mAh) for like $11 a piece and I'll see if I experience the same problem with those.

Hopefully it will be a batteriy issue like it was in your case.

[Mark_48]

Quiz time boys and girls......and I don't know the answer :)

On the Canon BP-511 battery there are (4) terminals. Two are marked (+) & (-) and the other two "B" & "D". I just took a Voltmeter and as expected read about 7.5 VDC on the (+) & (-). Across "B" & "D" they do not register any voltage, but have a resistance of about 24.1k ohms. They are also in some way connected to the (+) terminal.

What are the "B" & "D" terminals used for ?

You have 30 minutes to complete the quiz from the time you read this thread. You may use open books or any other reference material available to you. Asking for information in other forums is allowed, but you must divulge your information source. Your answers will be graded on correctness and completeness. This is not multiple choice !!!

[MrThanh]

one of the terminals (B/D) would probably be the thermistor, and the other would be used for communications between the camera and battery. precisely what they communicate i'm unsure of. my guess is that the battery relays temp info etc so that the camera can accurately detect power levels/status and also used for charging. canon probably have embedded somewhere in the circuitry another component that my generic battery does not have (or perhaps use a different thermistor), thus throwing off the battery meter.

are you sure that the B & D terminals are connected to the +ve (+) terminal? It is from my understanding that they are connected to the -ve (-) terminal.

[robertwgross]

Quick application of a volt-ohmmeter suggests that there is some non-linear device inside the battery pack. I can see its resistance by comparing the +/- voltage and the B/D terminals.

We've known for a long time that there is some type of current limiting device inside the battery pack, and it is not exactly a fuse.

---Bob Gross---

[Mark_48]

are you sure that the B & D terminals are connected to the +ve (+) terminal? It is from my understanding that they are connected to the -ve (-) terminal.
I stand corrected. Thank you. Between B & D & (+) I read a voltage. Between B & D & (-) I read 0 voltage. Between B & (-) I read about 99k ohms and between D & (-) about 75k ohms. So as you stated the connection from B & D appears to be to the (-) terminal.

[MrThanh]

ok looking into the battery port just now, there are no contact terminals for B&D. suggests that it is used purely for charging purposes since their respective terminals are on the charger.