Hello Everyone.
I was wondering what the sustainede out put is for this battery. As the raspberry pi 4 seems to need 3amps .
would I need to run two in series?
Thank you in avdance
Brian
Hello Brian
I suggest you get this https://www.ebay.com/p/USB-Digital-Current-and-Voltage-Monitor-DC-5-1a-30v-Amp-Voltage-Power-Meter-N3z1/15016918760?iid=253631580434&chn=ps&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&itemid=253631580434&targetid=595076201008&device=c&mktype=pla&googleloc=9011946&poi=&campaignid=1689407474&mkgroupid=74365777868&rlsatarget=pla-595076201008&abcId=1140476&merchantid=108434799&gclid=EAIaIQobChMIr6W1__Sb5AIVVluGCh0d4QsdEAQYBSABEgIZb_D_BwE or you can pick it up from amazon also for a bit more .
Connect it to the usb port on your compatible 3 amp power suppy and then connect it to a usb to type-c cable to the pi 4 they run it for a day with the pi doing what it is you want it to do ( make sure to connect all the external usb devices that aslo consume power . they it will record power consumpiton in mAh use that to see how long 8800mAh will last . and If you need to increase capacity by how much .
The official Raspberry Pi Power Supply can supply “up to” 3Amps out. That doesn’t mean your PI 4B is going to draw that much though. What current is drawn from the power supply depends on what the Pi needs to run plus the current needed to power what’s connected to it.
I usually go here for the low down on what a Raspberry actually uses.
https://www.raspberrypi.org/documentation/faqs/#pi-power
According to that the Pi 4B will draw ~600ma. It will be more obviously if its working hard. And up to 1.2 A for USB attached devices.
For my 2p worth…
Just in case it is not obvious - you can’t run a Pi off a “naked” Li-Ion battery - the battery will provide 4.2v when fully charged down to 3v when fully discharged meaning the battery voltage is too low for the 5v connection and (mostly) too high for the 3.3v connection though I believe directly wiring to 3.3v is not recommended anyway.
You could use something like the Pimoroni wide-input-shim between the battery and the Pi (for a 2 Amp max supply). You’ll also need a suitable charger to fill the battery back up again.
You might find it easier overall to simply invest in a couple of large capacity standard USB power banks. However you may need to actually test them to ensure they push out 5.1v at the required current.
Connect it to the Pi with a short USB to USB-C power lead.
This will give you 5V out and up to 2A out, and recharge the battery.
I have one but haven’t put it to good use yet. I also have a couple of Powerboost 1000c’s on the go here. They do the same thing but are only good for up to 1A out.
I’ve used a 6600 MAH battery. Its 3 2200 MAH cells in parallel. I’ve only ever run it for maybe 3 or 4 hours total at a stretch. The last time out power went off. Usually I only run it for an hour or two. I picked that cell because it can supply a lot of current into my powerboost. I’m likely close to drawing 1A out. At ~3.3V thats ~1.5 A being drawn from the battery. Plus any lose in the boost process.