Not sure how to best power my pi project (Battery)

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HouseTully
 
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Not sure how to best power my pi project (Battery)

Post by HouseTully »

I am doing a Raspberry pi (3B+) project running on battery. I have a PowerBoost 1000C which powers the pi and peripherals just fine but when I add the screen it gets too low on voltage. I am using a 6600mAh Lithium Ion Battery Pack as a power source.

I need to find a way to also power the screen via battery and not sure the best way to go about it. If I power everything from the wall it all works as it should so I know it's just a power flow from the battery issue.

Can anyone help with this?

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adafruit_support_mike
 
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Re: Not sure how to best power my pi project (Battery)

Post by adafruit_support_mike »

Try using a PowerBoost 1000 Basic instead.

The PowerBoost 1000C has a hard upper limit of 1.1A @ 5V output. Evidence from the field shows that trying to get more is a reliable way to kill the MCP73871 LiPo charger, which manages current from the LiPo to to the boost converter.

The PowerBoost 1000 Basic doesn’t have that limit, and can deliver up to 2.4A @ 5V.

It’s been a while since I looked at the benchmarks, but IIRC the 3B+ can use up to 800mA when all four cores are active. That only leaves about 300mA for anything else, like a display.

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HouseTully
 
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Re: Not sure how to best power my pi project (Battery)

Post by HouseTully »

Thanks so much for the reply. So is there any viable option if I wanted to also power the screen via battery? Would it need its own battery and power boost? Is there a way to have a switch that turns both the screen and pi on at the same time?

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Re: Not sure how to best power my pi project (Battery)

Post by adafruit_support_mike »

HouseTully wrote:is there any viable option if I wanted to also power the screen via battery?

A PowerBoost 1000 Basic should be able to power both the RasPi and the display. Even assuming 1A of load from the RasPi, the 1000 Basic still has 1.4A of additional capacity.
HouseTully wrote:Would it need its own battery and power boost?

Building a two-supply system is possible, but you have to weigh the tradeoffs of additional hardware and cost. For a RasPi and display, it’s kind of iffy. When I do suggest a second power supply, it’s usually for speakers.. those are power hogs with a highly variable load, and people always seem to want louder sound than the existing power system allows.
HouseTully wrote:Is there a way to have a switch that turns both the screen and pi on at the same time?
If you do choose to use two PowerBoosts, you can connect a single swith to the ENABLE pins on both boards. That will let you turn both parts on or off at the same time.

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