In regards to the adafruit product you stock Powerboost 1000c it says that it provides an output of 1A, so as a Raspberry Pi requires 2.5A, this wouldn’t be sufficient? Or is it saying the charging current is 1A, but the output current can reach 2.5A?
If the latter can anyone recommend a suitable LiPo that can be used in conjuction with this PowerBoost 1000c for my raspberry pi?
Thanks for any tips and advice!
It’s saying the output is 1A and the input is limited to 2.5A (2A internal switch for the boost converter). Because it’s stepping up the voltage the current at the input is higher at the output. All the info is in the documentation https://learn.adafruit.com/adafruit-powerboost-1000c-load-share-usb-charge-boost.
To explain why this is the case:
Input_Power = Output_Power + Losses.
Calculating losses as a percent efficiency:
Input_Power = Output_Power / Percent_Efficiency
So using a conversion efficiency of 85% (guess for low input voltage) and an almost discharged battery (3.0V) and the stated output of 5.2V:
(3V x Iin) = (5.2V x Iout) / 0.85
Therefore:
Iin = ((5.2x1)/0.85)) / 3 = 2.039A <= Close enough to 2.0ASo, does this mean if it only outputs 1A where the raspberry pi needs 2.5A it obviously isnt sufficient?
As from what I understand your saying that it can handle a 2.5A input to charge the LiPo?
It’s output current is only 1A output which isn’t enough for a Raspberry Pi.
The 2.5 A is the peak battery to Powerboost current (short time). The continuous current from the battery to Powerboost is 2A.
The battery charge current is 1A but the power supply required is 2A if you running devices off it at the same time as charging the battery.
Thank you! I appreciate you going to the effort to draw the diagram to make it clearer for me, clarified everything!
Odd how they advertise the PowerBoost plugged into a raspberry pi if it isn’t able to provide enough current for it.
So somehow I’m going to have to increase the current which isn’t really possible…
I have seen a Raspberry Pi 3 running on one of these but you can’t pug in any USB devices that take much power or do anything that pushes the Pi hard. So technically there are some tasks you can use it to power a Pi with but not all.
I’ve been using the PowerBoost 1000C with an RPi 3B+ and a device drawing some power from the USB; it works fine for me, but the power draw is less than the 2.5A ceiling. More like 1.2A peak, less than 1A typical. Note that for my application the Pi is not being pushed hard.
I did find that sub-standard cabling caused massive issues early on, so if you do use this solution make sure you have good cabling and connections; a 0.5 ohm (dodgy) cable caused a voltage drop that was a real headache!
If you’re going to be pushing the Pi hard or using a bit of power via USB, you probably need a different power solution.
Just saw your reply, perfect, thankyou!
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