What's The Deal With Charging Time?

[gibberish]

I've just dusted off my Pandora since it finally looks like PS1 and N64 emulation is picking up pace! Plus if my #350 pandora is faulty then it needs to find its fault before May since the warranty runs out then...

I remember it took ages to charge, but it really does take bloody ages. Like 4 or 5 hours! Is this normal? Can anything be done (in the future, software wise) to improve charging time? I don't really understand why it takes such a long time, my netbook has a battery of similar capacity and is fully charged in just over an hour.

 

[jonjandran]

Yea it seems a bit weird.

The charger is rated at 5v and 2A. The battery is a 3.7v 4000mAh Li-Po.

Apparently the Open Pandora is set up to only charge at a low rate so the system can be charged and used at the same time. So probably it charges at 500mA and the system is allotted 1.5A to run on.

So it would take around 8 hours to charge the battery fully.

That is my guess.

 

[WizardStan]

It currently charges at about 0.25C, taking about 4 hours to reach full charge. A little bit longer due to inefficiencies. We can safely push this to 0.5C, reduce the time to about 2 hours. That would consume the entire 2amps, minus whatever the system actually needed to run, but it'd also be pushing the charger hard, which would probably result in a lot more heat. Your netbook probably has a slightly bigger charger, I'm betting, capable of pushing more power, closer to 1C. For a battery of similar capacity to the Pandora, this would require a minimum of 4amps, but I've seen some laptop chargers claim as much as 10amps, if I recall correctly, to not only charge in less time but also keep the system running at peak performance.
So yes, of course your netbook is going to charge faster, it's charger can supply far more power.

 

[CPUnltd]

has anyone considered a standalone battery charger as an accessory (like what they have for current cameras and such)? something you can put the Pandora's battery in and just charge in like a 30min period or something? This would be especially great for those of us who bought an extra battery. of course, you'd have about 30 secs of downtime while swapping batteries, but it's well worth it, wouldn't you agree?

 

[Middo]

has anyone considered a standalone battery charger as an accessory (like what they have for current cameras and such)? something you can put the Pandora's battery in and just charge in like a 30min period or something? This would be especially great for those of us who bought an extra battery. of course, you'd have about 30 secs of downtime while swapping batteries, but it's well worth it, wouldn't you agree?

I could live with 30 seconds downtime!

 

[chris_c]

has anyone considered a standalone battery charger as an accessory (like what they have for current cameras and such)? something you can put the Pandora's battery in and just charge in like a 30min period or something? This would be especially great for those of us who bought an extra battery. of course, you'd have about 30 secs of downtime while swapping batteries, but it's well worth it, wouldn't you agree?

I could live with 30 seconds downtime!

I can smell the burning already

 

[CPUnltd]

haha... I don't think it would... as new as the tech in batteries is now, it should be at least as capable for charging of that speed as 2 2500mA Energizer AA batteries (and those travel chargers can handle charging 4 of those AA batteries in 15 or 30 mins without any burning smell...

 

[chris_c]

you'd have about 30 secs of downtime while swapping batteries, but it's well worth it, wouldn't you agree?

30 second charge you'll *defiantly* smell burning!

for the sake of humor we were both being pedants

 

[CPUnltd]

either you missed the point or you're purposely making a joke of a misread statement (or both )... the 30 seconds of downtime would be swapping of the low battery for the full one (if you bought an extra battery)... the charging of the battery would be more like 30 mins to an hour...

 

[chris_c]

bit of both that an 3 hours sleep in the last 2 days....

 

[CPUnltd]

seems like I'm being surrounded by people who aren't getting enough sleep... you're the 3rd one in the last hour... I'm sure yours is Pandora-related though...

 

[chris_c]

sadly it's my health which could be better, and to make matters worse I have just got my pandora back! but it won't make me loose too much sleep, as coding while tired is most counter productive - so much so I almost never do it!

 

[CPUnltd]

ouch... sorry to hear that...

 

[Esn]

Just for the record, I don't have a problem with the charging time...

Also, there may be chargers that can charge AA batteries in 15-30 minutes, but I've heard that the charge dissipates quicker than usual if they are charged at that speed.

 

[Chaser]

i believe the only stand alone charging option for the spare battery is to be found within the package for the EnergiserXP4000 USB battery pack available from carphone warehouse, WHSMith and Amazon. In the package is a small pink adapter that can be clipped to the batteries contacts and plugged to the mains, rather than charging the supplied XP4000 pack. The original poster who mentioned this device did not actually state he owns one or has tried it, but its the only device I know of. OPT could not be expected to branch into making such a Pandora branded device, as the market would be tiny within a tiny market already. Worth a shot and I would have done so already if I wasn't always skint.

Worth a look perhaps? http://www.amazon.com/Energizer-XP4000-Universal-Rechargeable-Power/dp/B0029U2WTG

http://www.whsmithentertainment.co.uk/electronics/portable-power/energizer-xp4000-xpal-portable-power-pack/10196386.html (note the line : Charges all internal batteries with supplied adapter) - SOLD OUT Grrr

http://www.carphonewarehouse.com/phone-accessories/blackberry-accessories/blackberry-power/buy/ENERGIZER-XP4000-BLA (doesnt mention the external adapter, so you'd want to see it in person to check its there)

 

[OilySalmon]

It currently charges at about 0.25C, taking about 4 hours to reach full charge...We can safely push this to 0.5C, reduce the time to about 2 hours. That would consume the entire 2amps, minus whatever the system actually needed to run, but it'd also be pushing the charger hard, which would probably result in a lot more heat.

I'm not sure I'm completely understanding this. The charging circuit/device in the Pandora can safely reach 0.5C, but it would be pushing it too hard? Is it currently set to 0.25C just for safety? I don't quite see the point in charging it below-spec.

 

[chris_c]

It currently charges at about 0.25C, taking about 4 hours to reach full charge...We can safely push this to 0.5C, reduce the time to about 2 hours. That would consume the entire 2amps, minus whatever the system actually needed to run, but it'd also be pushing the charger hard, which would probably result in a lot more heat.

I'm not sure I'm completely understanding this. The charging circuit/device in the Pandora can safely reach 0.5C, but it would be pushing it too hard? Is it currently set to 0.25C just for safety? I don't quite see the point in charging it below-spec.

as wizardStan said

That would consume the entire 2amps, minus whatever the system actually needed to run

if you were to actually want to use your pandora while the battery was charging the mains adapter would get hot! and in any case the battery life could probably be degraded too.

Far far better to charge over 4 hours, all said and done this is *less* that 40% of the discharge time, and you get to use your pandora while its charging.

You can always leave it to charge overnight - I believe someone has even created an easy to use script that will shutdown your pandora once its fully charged.... o

 

[Kur53]

Do you by chance know where to find said script?

 

[Zero3K]

You can find it here:

http://www.gp32x.de/board/index.php?/topic/58794-a-script-to-shutdown-after-charging/

 

[WizardStan]

I'm not sure I'm completely understanding this. The charging circuit/device in the Pandora can safely reach 0.5C, but it would be pushing it too hard? Is it currently set to 0.25C just for safety? I don't quite see the point in charging it below-spec.

It isn't the Pandora or the charging circuit that has a problem, it's the charging block. The Pandora's battery should be able to handle being charged in about an hour if you needed to (although I'm told two hours is the optimal maximum rate for lipo), but this would require a charger rated for over 4 amps, probably closer to 6. I'm looking over the chargers for many of my other electronics, and they all say 2amps. Even the adapters for my external hard drives are all 2 amps. The only one that produces more is my laptop, and even that's only 4amps. Long story short: if you want to charge faster, you need a more powerful charging block, and those just don't exist as off the shelf parts; you'd have to get something probably more custom and certainly more expensive.
I'd write a script to set it to do the 2 hour charge thing, but I am genuinely afraid of the prospect of these chargers burning out or overheating and catching on fire. It's just safer to keep well below the maximum rating and take your time rather than push your luck and risk serious injury or worse.