How Hot's The Battery Gonna Get?

[zazen666]

just wondering

 

[fischju2000]

Craigix, how is the battery level after the few hours of play?
How warm is the unit after your extensive play?

Thanks!

The unit does not get hot at all. I've used the Pandora for about 7 hours so far.

 

[darien]

I think the only time any part of the unit would get warm is during charging, using WIFI, or covering the LCD while it's on.

 

[MWeston]

I've done back to back charge and discharge cycles for days at higher than normal loads while teaching the fuel gauge and I've never noticed the battery change from room temperature. The charging circuitry makes the most heat as it has to convert 5.2V down to 3.3-4.2V @ 1A (my current setting) and dissipate the wasted energy through the PCB.

 

[jonlad1]

Is there any news from the MP factory? Do we have an ETA on you receiving the new samples?

 

[droneb]

MW, have you tried/is it possible to put 2 or more Batts on paralel, to increase the already massive
Batt mAh, or it could damage the panda or the Batt Safety Circuit.

also if already done, how would the Fuel Gauge Behave?

i intend to do this on the future. (also im afraid ill order to get that xtra protective Box)

 

[El Jefe]

MW, have you tried/is it possible to put 2 or more Batts on paralel, to increase the already massive
Batt mAh, or it could damage the panda or the Batt Safety Circuit.

This is relevant to my interests

 

[pelrun]

Parallel cells will work without changes to the hardware (for instance, Sparkfun sells a 3 cell 6Ah battery like that), however you really need to have the cells fairly closely matched in internal impedance for the configuration to work well and load the cells equally.

Oh, and it'd probably confuse the battery meter

boring technical explanation: serial configurations act as a voltage multiplier (cell voltage X number of cells in series) whereas the parallel configurations act only as a capacity multiplier (assuming identical cells here.) Since the voltage of the 2p battery is the same as the 1p, the Pandora will run off it happily. Additionally, the constant-current/constant-voltage regime used to charge Li-Ion cells (which has to be *very* rigidly followed otherwise literally *BOOM* happens) is fairly insensitive to capacity increases, so charging should be happy too. It just takes longer.

That said, you still probably shouldn't meddle with this unless you're quite familiar with how Li-Ion batteries work and are charged. After all, they can react very badly if you make the wrong kind of mistake - the aforementioned *BOOM* is the usual result. And it's no ordinary fire either - don't expect to be able to put it out.

 

[Yoyobuae]

I imagine that getting both batteries to match properly would be a pain.

Maybe if it were possible to replace the battery without powering down Pandora. Then you can simply carry the extra battery (inside it's convenient battery cover) and switch it when needed.

Perhaps a bit late, it would've been nice if an ultracapacitor was integrated into the power supply to give you 10~20 seconds before losing power after battery is removed (with Pandora in low power mode preferably). This should be enough to switch battery, I think.

This ultracapacitors are becoming quite cheap/small/powerful. I've gotta play with them at some point.

 

[openthebox]

Are there any space between the battery and the battery cover?
I want to see if I can store microSDs there if there is no heat problem from the battery.

 

[darien]

Are there any space between the battery and the battery cover?
I want to see if I can store microSDs there if there is no heat problem from the battery.

The battery is probably slightly mushy like plasticine, so I'm assuming you could fit it in there if you really wanted.

 

[mindlord]

Are there any space between the battery and the battery cover?
I want to see if I can store microSDs there if there is no heat problem from the battery.

I would strongly advise against putting any foreign object in the battery compartment. The battery is not in a hard protective shell. and LiPo batteries can and will erupt is a cataclysmic fireball if punctured.

 

[openthebox]

I would strongly advise against putting any foreign object in the battery compartment. The battery is not in a hard protective shell.

Did not know that, thanks for pointing that out.

and LiPo batteries can and will erupt is a cataclysmic fireball if punctured.

I guess this thing can throw a good fireball.

 

[GizmoTheGreen]

HADOUKEN

 

[DaMummy]

SONIC-BOOM!

 

[Tor]

Heed the advice of mindlord and pelrun, please. They're right on the money. Don't mess around with li-ion or li-poly batteries. And if you wonder why a puncture should matter, it's because water and lithium is an explosive combination - the humidity in the air is enough.

 

[Bosbeetle]

thank goodness there not francium ions than

http://www.youtube.com/watch?v=Ft4E1eCUItI

 

[pelrun]

Actually, a puncture is really bad not because of water ingress, but because there's a multilayered sandwich of conductors inside the cell. If you puncture or crush the cell then you have a high risk of shorting out part or all of the cell, which causes the cell to get very hot, very quickly, then go *BOOM*.

There are quite a lot of Lipo explosion videos on youtube - for instance: http://www.youtube.com/watch?v=4OsBc8RqSKU

 

[Nova]

Actually, a puncture is really bad not because of water ingress, but because there's a multilayered sandwich of conductors inside the cell. If you puncture or crush the cell then you have a high risk of shorting out part or all of the cell, which causes the cell to get very hot, very quickly, then go *BOOM*.

There are quite a lot of Lipo explosion videos on youtube - for instance: http://www.youtube.com/watch?v=4OsBc8RqSKU

Holy reptar!

Can/could this reaction be triggered just by dropping the unit?

 

[Gein07]

Actually, a puncture is really bad not because of water ingress, but because there's a multilayered sandwich of conductors inside the cell. If you puncture or crush the cell then you have a high risk of shorting out part or all of the cell, which causes the cell to get very hot, very quickly, then go *BOOM*.

There are quite a lot of Lipo explosion videos on youtube - for instance: http://www.youtube.com/watch?v=4OsBc8RqSKU

Should I look into buying some flame retardant pants before I get my pandora? I had no idea such a violent reaction was possible. It might be safer just to hook the thing up to an unlicensed nuclear accelorator.