Hello,
I’m making a handheld out of a Raspberry Pi 4.
So I found that one of the features of the "LiPo SHIM for Raspberry Pi ",
will automatically do a safe shutdown of the Raspberry Pi, when it has a low battery.
So far so good.
But I want to be able to charge the battery as well,
without having to get the battery out of the handheld case everytime it needs to be charged.
On the product page it says :
" You will need a separate charger to keep your LiPo/LiIon batteries topped up!
We recommend the Adafruit Micro Lipo or PowerBoost 1000 Charger"
Does anyone here know how we are supposed to connect the Powerboost 1000c to the Lipo Shim ?
I’ve read somewhere that you can use a “double pole double throw switch”,
but no info on how to do that. And also no info on wether or not the safe shutdown features will still work when making this connection between the Lipo Shim and the Powerboost charger.
Sure, the Powerboost 1000c has a low battery (LBO) pinout, but you can’t connect this directly to the GPIO pins, but the GPIO pins can only handle 3.3v input.
The voltage that comes from the LBO pinout is higher than 3.3v.
So after lots of searching I came across the Lipo Shim,
which does exactly what I want right out of the box.
Except the charging the battery part.
So can anyone help me (someone with almost no technical experience)
figure out how to have a shared connection between the Lipo Shim, the battery
and the Powerboost 1000c charger and make it that the low battery safe shutdown feature still
works ?
Thanks in advance.
Greetings,
Soxbrother
I think that’s an “instead of”, rather than “with”. This will work, I have one wired up to a standard Powerboost 1000 (not the C version).
Thanks for the reply, but if I use this instead of the Lipo Shim, with a Powerboost 1000(c),
how can it safely shutdown the pi when the battery is low ?
On the product page there’s no mention of such features.
You can use it with the LIPO Shim, I just happened to use mine with a Powerboost.
Sorry for the confusion.
You plug your battery into the Batt connector on the LIPO charger. Then the load terminals of the charger go to the battery in on the LIPO shim.
Are you aware that the max current out for the LIPO Shim is 1.5A?
Is that going to be enough to drive a Pi 4B and a display?
Might be iffy just driving a Pi 4B?
So you think I shouldn’t be using a Lipo Shim with the Raspberry Pi 4B ?
1.5A sounds indeed low.
I find it strange that there’s so little information out there on how to use this, not even a single video is found about the Lipo Shim. No tutorials with pictures, no videos.
It’s like no one has made any projects with it.
Also hard to believe that there isn’t a ready-made solution out there that does everything, just plug and play.
On the one hand you have the Lipo Shim that does almost anything needed for the project, except of charging, on the other hand you have the Powerboost 1000c, that does the charging, but can’t in a simple way send a low battery signal to the pi to safely shut it down.
Also not finding a solution for powering off the Lipo Shim with a butto. So it keeps drawing power of the battery. On the product page it says you can connect the EN pin to ground.
But there isn’t anyone that did this it seems, because no pictures or videos of this are found.
Let’s, for a moment, assume that the Lipo Shim does deliver enough power to the Pi4 and the screen.
Then I only have to figure out how to start the Pi 4 with a button. I think the Lipo Shim starts the Pi as soon as you connect the battery, right ?
If it can be achieved that the Pi doesn’t start when connecting battery, and only start with a push of a button that would be great and then instead of searching for a way to turn off the power, I could just disconnect the battery everytime I’m done using it and reconnecting the battery the next time I use it.
Ok, I know it isn’t ideal, but unless anyone can show me another way, that’s the only way it can be done for the moment.
I feel your Pi pain, I do own the item ,never used it much, I just read a review on it in a 2016 magpi issue, ,it looks like it could maybe be coded to do what you want ,“me no coder” check out the magpi artical .good luck .https://www.raspberrypi.org/magpi-issues/MagPi51.pdf
I for the most part use Adafruit Powerboosts. All but one are the C model with battery charging. If its a headless setup I do my OS shutdown via a button press. My running python file watches for a set GPIO pin to be grounded, then does a shutdown now command. That switch is just a normally open non latching switch / button.
Once the Pi shuts down I ground the enable pin on the Poweerboost to turn off the boost section and save the battery. It can be recharged like that also, only the boost section is turned off. That switch is a latching switch that stays in position when moved.
Thanks for the replies.
Another problem arises if using the Lipo Shim.
Because it sits on top of the Raspberry Pi,
I can’t use a heatsink with integrated fan, like for example the Geeekpi fan with PWM
Geeekpi fan with PWM
So I’m thinking more and more of just using the Powerboost 1000c and shutting the battery off with a switch/button after manually shutting it down from the retropie menu or with a seperate button that uses the safe shutdown script.
Then I only need to use some sort of light pipe connected to the different leds on the powerboost, to make the leds visible outside the case.
The Powerboost 1000 C is only good for 1 amp out.
The Powerboost 1000 is good for almost 2A but won’t charge your battery.
I needed more than 1 A which is why I went with a 1000 instead of a 1000c, and a separate LIPO charger.
The following is good for 2.5A out, and has charging. No enable pin though.
MP2636 Power Booster & Charger Module – Pimoroni
You could solder the LIPO Shim to a stacking header, then plug a hat on top of it. Assuming there are no pin conflicts etc.
I had just read this as well, about the Powerboost 1000c not having enough to power the Pi 4.
Just when you think you have a solution,
you’re back to square 1.
Can you also connect an on/off switch to the Powerboost 1000, cutting power to the battery ?
Do you need a button as well to start the pi ?
Or does the pi start the moment you slide the switch back to the “on” position ?
If you do a shutdown, and then ground the enable pin, it removes power to the Pi.
The battery is still connected but the boost section is off, no 5V out and no drain on the battery.
Unground the enable pin and the Pi powers up like it does when you plug in your power supply. The boost section turns back on and sends 5V to the Pi.
Ok.
So the Powerboost 1000 is enough to power a Pi4, a screen
and communicate with a bluetooth controller at the same time ?
The only other option is a powerbank, but they are so thick
Iffy at best IMHO. My Powerboost 1000 is powering a Pi Zero, Unicorn Hat HD, LED Shim, and a hand full of sensor breakouts to measure weather and light.
I was getting occasional undervolt warnings on my monitor while testing and doing my coding with a 1000c. Usually happened when my Unicorn hat HD was on full bright and displaying white text. The 1000 fixed that issue, but I’m only using a Pi Zero.
Ok, thanks for the info.
Maybe someone with a battery powered Pi4,
will answer here in the future.
Meanwhile I’ve posted the question on the Adafruit forums,
maybe some answers there, we will see.
Has anyone in here used a power bank before to power your Raspberry Pi ?
I have a few questions about that :
-
So I imagine connecting it to the Pi will turn the pi on,
but after you shut it down using the retropie menu or with a safe shutdown button,
what happens with the power bank ? Will it drain the power bank battery ?
-
How do you turn the Pi on, after shutting it down ?
Does it go in some sort of bootloop ?
Or does it indeed stay off and can you simple use a button connected to one of the GPIO pins, to trigger a start of the Pi ?
Once you shut the Pi down, it should be the same as shutting down and not unplugging your power supply. The power bank will likely stay on but only supply a trickle of current. Over time the battery will drain. Mine still sense a load and stay on, even though the Pi is off. The Pi’s Red Power LED stays on. Mine are on the inexpensive side so as always YMMV. The more expensive better quality ones might actually turn off, I don’t know for sure though? I have limited experience with them, I grabbed a couple that were on sale to play around with.
One niggle is, most power banks won’t recharge the battery while on. The ones I have won’t, I have to remove the load (unplug the device its powering) for it to go into charge mode. It can’t do both at the same time.
All that being said, by default, if you do a shut down and leave your Pi powered up. Don’t unplug the power supply etc. Grounding GPIO 3 will have it boot up again. I do this on my Pirate Radio. I have a mini arcade button wired up to ground GPIO 3 when pressed.
You can also have it shut down by grounding GPIO 3 with a dtoverlay entry in config.txt.
dtoverlay=gpio-shutdown
That won’t work if i2c is enabled, you then have to use an alternate pin, which I have done.
dtoverlay=gpio-shutdown,gpio_pin=17,active_low=1,gpio_pull=up
GPIO 17 is what I used but it doesn’t have to be 17.