08-13-2023, 06:16 PM
(This post was last modified: 08-13-2023, 06:50 PM by hoarfrosty.)
For quite awhile now I’ve been looking for a suitable battery to run this SBC. I’ve seen several posts which helped determine that it can’t be powered by usb-c, or the onboard lithium battery port. I don’t know much about electricity, but there has to be a solution to run the unit without plugging into the wall. My MacBook Air runs & charges off usb-c, and it seems it would need much more power than an SBC. It also seems very inefficient to run an expensive battery bank to go from DC - AC - DC. I’m also not going to carry a 12V car battery around in my backpack.
Has anyone found a solution to battery power the RP64? I will run headless, so no additional accessories are needed (except for onboard or usb Wi-Fi adapter).
Power Input: 12V 3A or 5A type M 5.5mm OD/2.1mm ID barrel type DC Jack Power Supply.
08-13-2023, 07:21 PM
(This post was last modified: 08-13-2023, 07:25 PM by wdt.)
I can say that it draws 2.5-4W, depending on load
I think my rpp has a slightly defective power supply chip,
for the 1st few days all I got was a flashing green light,
this is a 5V -> GRD connection. So, nothing worked... at all
2 or 3 different power bricks, then I hooked it up to my bench ps,,
and it will start to work at 7V, but not boot,,, maybe my bad ps chip?
I ran it for a few days at 13V, no problem
(the bricks all had a 1 V ripple, 11v to 12v, the brick that works has a 1/4 V ripple)
The schematic says up to ~18V, so you have some headroom
So... why not 3 lithium bats in series, this might give you 6-8 hrs run time
(depending on C of bats and what you have hooked up)
There is a direct connection to pcie port, so maybe not overvolt anything in it
There are countless shapes and sizes of 12V batteries. Common (and cheap) ones are intended for exit signs and emergency lighting.
https://duckduckgo.com/?q=12v+lithium+ba...&ia=images
BTW, I hope you know....
the C (capacity, Ampere-hrs) in the majority of cases are a LIE
(because the claim is ALWAYS greater than reality)
Aliexpress is particulary bad at this
Now, within 10% is not a lie because of the variability of electronics
Genuine south Korean and Japanese claims are often accurate
Thanks for the help guys, I think a lot of people will benefit from this info. Instead of running the Pine power supply (AC adapter with barrel jack), would it be feasible to have a power bank putting out 12V DC, and use a cord with a male barrel-jack on both sides?
There are a lot of UPS's on Amazon, actually so many that it's overwhelming. This is the closest thing I've found in my search
Unfortunately many of those are also very expensive. For this project I don't want to spend more than about $20 (if possible).
I'd say that you'd have to try it to see if it works. Also consider safety; if it isn't legitimately UL listed, it may or may not be actually dangerous.
Very expensive is relative; $20 isn't a whole lot of money these days. I don't know how you're going to get a battery *and* good way to charge it for that price.
08-14-2023, 09:47 PM
(This post was last modified: 08-14-2023, 09:53 PM by wdt.)
$20?...only if you build it yourself
3 good quality 18650 cells, a 3 cell battery holder, a "h" plug and wire,
some way to charge it,,, that would be about $20
You most definitely do NOT NOT NOT want to charge normal lithium cells over 4.2V
3 x 4.2 =12.6 which would be fine, unless there is something in pcie slot consuming 12v power
If it would 'drop out at 3.6 x 3 (battery dead) = 10.8V,,, I don't know
I suspect not
The amazon thing only has 4 18650's in it, normal capacity, but no sales or reviews
The cheap way would be to recycle "dead" laptop battery packs, often 6 cells
3s2p (3 series, 2 parallel) ,often only 1 or 2 dead cells, usually some life left in rest
Thanks guys, I just threw that number out. It seems like the price of components are all over the place. I just picked up a couple Waveshare e-ink displays for $21/each. I'm still kind of blown away that this project could require multiple laptop battery cells, when we can use usb-c to power and charge so many complete laptops.
From the number of similar questions on this and other boards, it seems like there's a strong market. Unfortunately shipping batteries from China would probably take a long, long time.
One thing I can say is that the 12V barrel-type requirement was clearly described before I bought the board, so it's not a surprise.
But usb C, with right chips and handshake can go up to 20 V
Sorry, h barrel is for pbp, yes 5.5 x 2.1
If you want a pcie slot, you have to get 12 V to it, somehow
Well, in the past few weeks I’ve happened upon a couple potential options.
1) I found 3 Panasonic laptop batteries next to the battery recycle box at work. Unfortunately I haven’t been able to test them as I need a new multimeter (and to do some research).
2) Do you guys have any thoughts on this battery enclosure? If the 8 AA batteries (12V 3000-4000 mAh) put out enough power it could be an option. It would be a pain (and fairly expensive) to buy AA’s, but the thing’s only $6 + shipping, and one benefit is that the USPS would deliver it to my PO Box.
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