Lithium Ion Polymer Battery - 3.7v 500mAh
Moderators: adafruit_support_bill, adafruit
Please be positive and constructive with your questions and comments.
- CodyTheodore
- Posts: 4
- Joined: Sun Dec 14, 2014 2:31 pm
Lithium Ion Polymer Battery - 3.7v 500mAh
Noob Question: Can I use a 500mAh battery with the Powerboost 500c? In theory it sounds ok, but will the battery always deliver 500mAh? or over time will the battery start to deliver less power?
- Franklin97355
- Posts: 23910
- Joined: Mon Apr 21, 2008 2:33 pm
Re: Lithium Ion Polymer Battery - 3.7v 500mAh
500mAh is a capacity (500mA for an Hour or 250mA for 2 Hours) A LiPo battery will also have a discharge rate (something like 2C) which will tell you the max current rate you should draw.
- CodyTheodore
- Posts: 4
- Joined: Sun Dec 14, 2014 2:31 pm
Re: Lithium Ion Polymer Battery - 3.7v 500mAh
Thanks, So this battery would be enough to power a 5V device using the Powerboost 500C? and this means that a battery of any capacity can be used in conjunction with the Powerboost 500C?
- Franklin97355
- Posts: 23910
- Joined: Mon Apr 21, 2008 2:33 pm
Re: Lithium Ion Polymer Battery - 3.7v 500mAh
That is correct.
- steverobey
- Posts: 174
- Joined: Thu Jan 01, 2015 7:47 am
Re: Lithium Ion Polymer Battery - 3.7v 500mAh
Can I slightly tweak the 500C so that it will power a Raspberry Pi with a GPIO connected capacitive touch display.. and a wireless card.. and a USB keyboard? :D
I want to make a Pipboy 3000 and am looking at the 500C as a possible power solution. It's either that or something else is going to have to be engineered.
I want to make a Pipboy 3000 and am looking at the 500C as a possible power solution. It's either that or something else is going to have to be engineered.
- adafruit_support_mike
- Posts: 67446
- Joined: Thu Feb 11, 2010 2:51 pm
Re: Lithium Ion Polymer Battery - 3.7v 500mAh
Have you ever seen the movie "Apollo 13"?.. that section where the team at NASA is trying to find a way to turn on the computer in the command module using no more than 11A?
Yeah.. like that. Technically possible if you do everything right and really work to avoid going over the limit. Not a "flip the switch and go" proposition though.
Yeah.. like that. Technically possible if you do everything right and really work to avoid going over the limit. Not a "flip the switch and go" proposition though.
- steverobey
- Posts: 174
- Joined: Thu Jan 01, 2015 7:47 am
Re: Lithium Ion Polymer Battery - 3.7v 500mAh
Had anybody at Adafruit or elsewhere tested say a Raspberry Pi with one of your displays designed to plug into the GPIO simply powered on, booted up and displaying the shell on screen to see how much current the whole thing is pulling down? If I have a good idea of the output im going to need that will give me a direction to go with my next purchases. Today is pay day and I'm itching to buy some stuff lol. Also, bonus points to you for the movie reference, that's actually one of my favorites, which, now I feel like I should watch again followed by a simulated trip to the moon in kerbal space program... Okay so I know why I'm doing today lol. Thanks.
- adafruit_support_mike
- Posts: 67446
- Joined: Thu Feb 11, 2010 2:51 pm
Re: Lithium Ion Polymer Battery - 3.7v 500mAh
https://learn.adafruit.com/embedded-lin ... n/overview
The model B RasPi idles close to 340mA and adding a PiTFT will add about 75mA.. call it 425mA nominal. The USB ports are hardware limited to 140mA, and multiple devices will probably max that out.
The model A RasPi idles at only 150mA and peaks around 225mA when connected to a USB keyboard and HDMI monitor. That would probably be your best bet.
The model B RasPi idles close to 340mA and adding a PiTFT will add about 75mA.. call it 425mA nominal. The USB ports are hardware limited to 140mA, and multiple devices will probably max that out.
The model A RasPi idles at only 150mA and peaks around 225mA when connected to a USB keyboard and HDMI monitor. That would probably be your best bet.
- steverobey
- Posts: 174
- Joined: Thu Jan 01, 2015 7:47 am
Re: Lithium Ion Polymer Battery - 3.7v 500mAh
I just wanted to post here as an update as well as on a somewhat related thread that I was able to power my Raspberry Pi Rev. B and a small TFT display, wireless usb keyboard and USB WIFI adaptor for about two and a half hours with the PowerBoost 500C without modifying any of the equipment short of eliminating all of the extra wire by direct connecting everything with a few short pieces of IDE hard drive cable. So while I keep being told that it's not possible, it is, but I understand why from an engineering standpoint it's "Safe" to say it isn't.
- adafruit_support_mike
- Posts: 67446
- Joined: Thu Feb 11, 2010 2:51 pm
Re: Lithium Ion Polymer Battery - 3.7v 500mAh
Yeah.. engineers (especially support engineers) think in terms of 'reliable'.
Researchers think in terms of 'possible' and marketing departments think in terms of 'it might not be impossible'. ;-)
Researchers think in terms of 'possible' and marketing departments think in terms of 'it might not be impossible'. ;-)
Please be positive and constructive with your questions and comments.