Topic: how to tell when a SD battery is dead?

[Teen Wolf Blitzer]

Here goes.  Recorded Little Feat last night.  No problems.  Galactic was next.  Started rolling.  About 10 minutes in the 744 shuts completely off.  WTF?  Power it back up.  Hit record.  Does the same thing in about 5 minutes.  Swapped to another battery and got the remainder of the show.  My questions are...

1.  Is this what the 744 does when the battery dies? (I might add all the files saved on the 744)
2.  Is there warning lights on the 744 telling you when a battery is low?
3.  Has anyone else ever had this problem?

I must confess I rarely pay attention to the battery.  Just charge it up prior to showtime and I've never had a problem.  Bummed I missed some Galactic.   

EDIT:  I wanted to add something that concerns me a bit.  Last year at Pickathon (a festival) it was over 100 degrees for 3 days.  I ran AC.  The 744 shut off twice over the course of the weekend to which I fired it back up and continued recording.  I attributed it to the heat but now I'm a bit worried.  Same scenario as above but I wasn't on battery power.  Thoughts?

[OFOTD]

Did you see what the voltage was reading before Galactic?   Do you have a smart charger?  If so what did it say when you put the battery on it after the show?

[Teen Wolf Blitzer]

Dave.

No I did not check the voltage
No I don't have a smart charger.  I charge on the deck.
I could put the battery back on and check it out?

Also Dave see my edit.  Worried....

Put the battery in question back on.  Says 7.1 V.

[page]

Dave.

No I did not check the voltage
No I don't have a smart charger.  I charge on the deck.
I could put the battery back on and check it out?

Also Dave see my edit.  Worried....

Put the battery in question back on.  Says 7.1 V.

I've seen mine die at 7.0v and I've seen it at an earlier stage in life make it to 6.8v (very briefly) before shutting down. Supposidly, they are supposed to get down to 6.7v (or just above 6.5v I think) before the unit turns off regardless of how much lower it will go. I've also seen the unit turn on, go through the boot sequence, and then die (twice in a row). Average 70s, indoors, around 7.1v or so. It's like it's circuit for overdraw circuit protector gets triggered when the battery gets low or something.

I think my current battery tanks just before it gets to 6.9v actually... 

[Teen Wolf Blitzer]

Hmm.  Well I swear it was charged before I left. ( meaning the light stopped blinking on the 744)  Maybe I misread it.  Or the battery is going out.  I'll do some tests.  Still worries me that the same thing happened last summer on AC.     Thanks for the input.

[OFOTD]

If I could make one VERY important suggestion......

Go out and buy a good smart charger.   

Sounds like that if you have been keeping up with a full charge through the unit that the battery is in fact starting to fail.    As the SD guys have said before charging the batteries in the unit offers no sort of smart charging or power conditioning.   

If you check the Team SD threads I know several of us have posted links to several very good (and affordable) smart chargers.

re: this happening on AC power:  I have heard of this before and seen a similar issue a few months ago.  AC power spike was the culprit we believe.    Not sure if its possible for a battery to spike before it dies though. 

[Teen Wolf Blitzer]

Thanks for the info Dave.  Are they pretty affordable?  Keep in mind I use battery power hardly ever.  I think last night was the first time in months easily.

[OFOTD]

Thanks for the info Dave.  Are they pretty affordable?  Keep in mind I use battery power hardly ever.  I think last night was the first time in months easily.

This is the dual well version of the charger I have.  Actually this is the newer model but appears to be close.  http://www.bhphotovideo.com/c/product/472879-REG/Impact_DPBCG_DP_BCG_Dual_Port_Li_Ion.html#specifications

Otherwise the Impact charger I have seems to be rebranded with a higher price here:  http://www.bhphotovideo.com/c/product/579802-REG/Pearstone_UFC30_UF_C30_Ultra_Fast_30.html

Keep in mind there are multiple plate adapters for all of your batteries.  Not sure what type of batteries your Canon HD camera take but I would assume there is an adapter plate for them too.

[it-goes-to-eleven]

The 7xx built in charger works great.   Never had an issue with it, almost never used my external charger.  I question whether there is such a thing as a "smart charger" for the lithium camcorder batteries.  They aren't like nimh batteries or nicads in that regard.  They don't have memory.  They have protection and charging circuits in front of them that limit how quickly they can be charged and how much load the cells see.

Another critical point... Like all batteries, these batteries are subject to drop damage.  The fact that they are lithium means the consequences can be more serious.  If a cell is compromised, bad stuff could happen.

I think it is essential to monitor the voltage from your battery on the recorder... Note it before you start, note if it is abnormally low.  At set break, is it where it usually is?  Maybe it starts at 8.0 or 8.2 and at set break it is 7.6, and 7.4 at show end...   Ideally, we would have a graph with time vs. voltage.  That would tell us when a problem was developing.   It would be a great 7xx feature.  It would also be possible for them to track the rate of voltage discharge and issue a warning to the user.  Sort of a "battery suspect" warning.

Lithium batteries do not like heat.  It reduces their effeciency and it shortens the life of the cell. It is possible that the battery has a thermal shutdown.

I had great success with the 6000 lithium in my 722.. I ran the same battery night after night and charged it in the unit, almost never removing it.

[notlance]

I've referenced this source serveral times on this forum, and it is still the best source of battery info I have found on the web.  This link is about Li-ion batteries, but the whole site is worth reading.

http://www.batteryuniversity.com/parttwo-34.htm

[johnw]

Thanks for the info Dave.  Are they pretty affordable?  Keep in mind I use battery power hardly ever.  I think last night was the first time in months easily.

This is the dual well version of the charger I have.  Actually this is the newer model but appears to be close.  http://www.bhphotovideo.com/c/product/472879-REG/Impact_DPBCG_DP_BCG_Dual_Port_Li_Ion.html#specifications

Otherwise the Impact charger I have seems to be rebranded with a higher price here:  http://www.bhphotovideo.com/c/product/579802-REG/Pearstone_UFC30_UF_C30_Ultra_Fast_30.html

Keep in mind there are multiple plate adapters for all of your batteries.  Not sure what type of batteries your Canon HD camera take but I would assume there is an adapter plate for them too.

The Pearstone looks to now be discontinued. Shame because that thing charges to full capacity very quickly

[dactylus]

Thanks for the info Dave.  Are they pretty affordable?  Keep in mind I use battery power hardly ever.  I think last night was the first time in months easily.

This is the dual well version of the charger I have.  Actually this is the newer model but appears to be close.  http://www.bhphotovideo.com/c/product/472879-REG/Impact_DPBCG_DP_BCG_Dual_Port_Li_Ion.html#specifications

Otherwise the Impact charger I have seems to be rebranded with a higher price here:  http://www.bhphotovideo.com/c/product/579802-REG/Pearstone_UFC30_UF_C30_Ultra_Fast_30.html

Keep in mind there are multiple plate adapters for all of your batteries.  Not sure what type of batteries your Canon HD camera take but I would assume there is an adapter plate for them too.

The Pearstone looks to now be discontinued. Shame because that thing charges to full capacity very quickly

^
Wow.  My pearlstone charger from B&H just arrived 3 days ago.  I guess that I got lucky.  This will be my "travel charger".