powerboost 500 charger problems
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- bbusch
- Posts: 6
- Joined: Fri Sep 26, 2014 12:08 pm
powerboost 500 charger problems
I'm using a 2700 mAh lipo from Adafruit and a Raspi B drawing 400-500 mA per my charge doctor. The battery is always in a state of discharge. No matter what I do short of unplugging the pi, the battery eventually drains. I've verified the voltage coming in at 5.2vdc. Any suggestions?
- Franklin97355
- Posts: 23911
- Joined: Mon Apr 21, 2008 2:33 pm
Re: powerboost 500 charger problems
What is the draw on the usb input port?
- bbusch
- Posts: 6
- Joined: Fri Sep 26, 2014 12:08 pm
Re: powerboost 500 charger problems
about .25 - .26 amps input to the powerboost without the Pi plugged in. Interestingly, it drops to .20 amps when the Pi is plugged in.
I'm trying to use this as a battery backup but it's useless if the only way to fully charge the battery is remove the pi.
I'm trying to use this as a battery backup but it's useless if the only way to fully charge the battery is remove the pi.
- Franklin97355
- Posts: 23911
- Joined: Mon Apr 21, 2008 2:33 pm
Re: powerboost 500 charger problems
If your USB port is providing 200ma and your Pi is using 500ma your battery will drain. You should try a different USB supply and cable.
- bbusch
- Posts: 6
- Joined: Fri Sep 26, 2014 12:08 pm
Re: powerboost 500 charger problems
I understand your logic so i bought a 3A power supply. The powerboost, battery and Pi are drawing .42A from the power supply. The Pi only draws .40A from the powerboost so the battery should be charging right? right now I'm watching the battery slowly drain. What's next to check?
- Franklin97355
- Posts: 23911
- Joined: Mon Apr 21, 2008 2:33 pm
Re: powerboost 500 charger problems
Could you post clear pictures of your board and the connections to it?
- bbusch
- Posts: 6
- Joined: Fri Sep 26, 2014 12:08 pm
Re: powerboost 500 charger problems
Edit: forgot the picture. ;-)
- adafruit_support_bill
- Posts: 88093
- Joined: Sat Feb 07, 2009 10:11 am
Re: powerboost 500 charger problems
You have to also account for charge efficiency (~80%) and the fact that 420mA @5v is equivalent to close to 600 mA @3.7v once you account for the voltage difference and the boost efficiency. So a net battery discharge would be expected with that load.
From the tutorial: https://learn.adafruit.com/adafruit-pow ... us-charger
From the tutorial: https://learn.adafruit.com/adafruit-pow ... us-charger
Just be aware that the charge rate is 500mA max, so if you're drawing more than ~300mA continuously from the 5V output side, the battery will slowly drain since the charge rate is less than the dis-charge rate.
- bbusch
- Posts: 6
- Joined: Fri Sep 26, 2014 12:08 pm
Re: powerboost 500 charger problems
So this product will not work for my application. It probably won't work for any running raspberry pi project since my B is drawing 400mA at idle.
Thanks.
Thanks.
- adafruit2
- Posts: 22148
- Joined: Fri Mar 11, 2005 7:36 pm
Re: powerboost 500 charger problems
400mA idle is *a lot* - we have a B+ here and it draws 150mA idle. we didnt specifically design this for the Pi, so it may not work for you...
- mrcw
- Posts: 11
- Joined: Tue Mar 17, 2015 1:49 am
Re: powerboost 500 charger problems
Seems like it's not a good fit for the Pi at all as common Pi models draw more power than this unit can keep up with and much more w/ typical use. The description seems to be leading people (including myself) to believe otherwise.
I think the first sentence gives people the wrong sense of how this device works and how the power flows:
I'm sure this nicely packaged board works fine for someone who is typically running off batteries or drawing closer to 100mA continuously but most of the Pi models use much more (original B uses over 400 idle and Pi2 with only ethernet uses 350, wifi dongle runs over 450) which is why they Pi manual recommends at least a 700mA power supply.
Please update the product description as it seems (from reading forums) this has been going on for months and a lot of people are finding themselves BANNED with the wrong product. Sure it's only $15 but with a $10 battery it was $38 to get it to my door... and much time lost. Next time I'll spend more time decoding the description or better yet check forums first.
Has anyone come up with a mod for this board to route the 5v supply side directly to the output while keeping the rest functional?
I think the first sentence gives people the wrong sense of how this device works and how the power flows:
PowerBoost 500C is the perfect power supply for your portable project! With a built-in battery charger circuit, you'll be able to keep your project running even while recharging the battery!
However both my PiB and Pi2 with all USB devices removed drained the battery while plugged in. I would add with a 300mA current draw it looks like the efficiency is below 80% not the "90%+ operating efficiency in most cases" ... so again not well suited as a UPS.a Pi works fine ... to act like a UPS.
... just be aware (or surprised in my case) that even though it's plugged into the wall it will drain the device's battery.Solder in the USB connector and you can plug in any iPhone or iPod for 500mA charge rate
I'm sure this nicely packaged board works fine for someone who is typically running off batteries or drawing closer to 100mA continuously but most of the Pi models use much more (original B uses over 400 idle and Pi2 with only ethernet uses 350, wifi dongle runs over 450) which is why they Pi manual recommends at least a 700mA power supply.
Please update the product description as it seems (from reading forums) this has been going on for months and a lot of people are finding themselves BANNED with the wrong product. Sure it's only $15 but with a $10 battery it was $38 to get it to my door... and much time lost. Next time I'll spend more time decoding the description or better yet check forums first.
Has anyone come up with a mod for this board to route the 5v supply side directly to the output while keeping the rest functional?
- bbusch
- Posts: 6
- Joined: Fri Sep 26, 2014 12:08 pm
Re: powerboost 500 charger problems
Thank you. Well said. Hopefully adafruit will take some action.
Please be positive and constructive with your questions and comments.