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60847662 No.60847662 [Reply] [Original] [archived.moe] [rbt]

Say I have a powerbank, and it's tucked away in a place I can't quite easily access (this is on purpose, it's supposed to be hidden for aesthetic purposes) and it isn't constantly being charged, is there any way you can think of to monitor the powerbank charge remotely? So when I notice it's running low or even flat out dead I can start charging it (via an usb switch connected to a power source) and when it is fully charged I can stop charging?

An usb voltage reader wouldn't work, since 99% of the powerbanks do their best to keep a steady 5V/1A (or 2A/3A) output until they're flat out dead. Hooking up something to the usb outputs would just show 5V until it's dead, and that wouldn't be much help.

tl;dr how to check a powerbank's charge level (think the leds on top of the plastic case that light up to tell you the current charge) remotely, without x-ray vision or a really shady chinese night webcam.

>> No.60847789

probe across the charge level indicators.

However, presumably the indicators aren't lit constantly so you'd need to rig a small circuit to:

1) trigger the level indicator intermittently
2) read the LED states

If only one LED lights up then you know it's near flat and that state could trigger something that alerts you, a light elsewhere most likely.

You could do it with a little PIC, a 12f629 would be ideal.
Bonus points; Power the PIC from the battery pack.

>> No.60847820
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Why not just keep it connected to the power so it only drains when the power is off.

>aesthetic purposes

You talk like a fag and your shit is all retarded. Ip powerbrick! Internet of things! Whoohoo this faggotry is finally here!

Delete yourself.

>> No.60847855

Not OP here but that would kill the cell quickly and you're a fucking idiot. Even with today's consumer battery technology "memory" is a thing you need to be concerned about if you want to keep your battery in good health.

OP wasn't asking for an "Internet of things" or anything of the sort, did you skip your fucking meds today?

>> No.60847874

Why would you hide something that is supposed to be portable?

>> No.60847991

Don't reply to him, he's an assblasted underage who didn't get a kiss from mommy tonight.

Basically I want to use the powerbank as a buffer to power 5V things in my car (I have 2-3 of them) even when the engine is off. Hooking them up to a powerbank would make them last even for days (as well as letting me charge my phone without turning on the engine to supply the charge).

The thing is I want the powerbank hidden behind the radio, where I know there's lots of space, and I'm looking for a way to monitor the powerbank charge without dismantling half the internals of my car every time. I could just go for gold and say "eh, it charges every time I turn on the engine so whatever [which is true]" but that is kinda meh and not a failsafe system in case something shits the brick and I end up with a flat car battery. So here's why I need to remotely monitor the charge of a powerbank. So far only >>60847789 has given me a solution but it's ludicrously overkill to put a fucking pic to prove across the leds of a powerbank for something like this.

>> No.60848020

>ludicrously overkill

Not really, you can get one for a few cents if you don't have any on hand.

Ah shit I realized i'm on /g/ not /diy/. The suggestion still stands though.

>> No.60848136

It's more effort than it's worth, that's what I'm saying
I could literally just use common sense and charge my phone / whatever when the engine is running, but it would be so cool to do something like this

Since you said to probe the charge leds to get the current state of charge, why not probe the cells directly? I know it's less safe, but it would still the job done

I'd rather find a way that doesn't require gutting a powerbank, something more ghetto, you feel me?

>> No.60848161

still op

Question: does the input voltage of a powerbank drop when it's fully charged? Does it change in any way depending on its charge state? Or will it just keep trickle charging forever?

>> No.60848219

They stop charging the batteries when they're full, otherwise you're just asking for an explosion.

>> No.60848265

>what is tricklecharging
>implying there's no protection against that

off you go

>> No.60848276

Off I go where?

>> No.60848402

What's "remotely"? Do you just need to be able to conveniently check it while you're in the car, or does it need to be accessible over the internet etc?

>> No.60848428

A USB endoscope, one that works with Android phones. Securely mount it to point at the indicators and snake it through to somewhere accessible.

>> No.60848445

>>60848428 (Me)
And a string/pulley mechanism able to apply pressure to the check button when pulled.

>> No.60848457

It doesn't sound like you want something which would start charging it automatically, so in that case instead of connecting a PIC to the LEDs you may as well just solder some wires to some external LEDs which can be somewhere visible without bringing the entire power bank into view. I assume it has some button to check the charge too, so you'd need to wire that out as well.

I can't really see a simpler solution than this, it's as barebones as it gets. Any automated solution is obviously going to require much more effort than this.

>> No.60848482

Because it'll be hidden in his sisters clothes hamper.

>> No.60848589

Yeah I was thinking about that too, but it's still very invasive

Ditching the power bank idea for a minute, any other ideas you might have?

Input I have a 12V Supply (180W max) that works only when the engine is running, on output I need at least 3-4 5V devices that need to be powered on externally from this 12V supply (so even when the engine isn't running) and off some sort of battery or something. But when said battery is running low I have to at least be aware of this, so I can turn on the engine when needed and let it charge.

>> No.60848603

I said go to bed kiddo

>> No.60848674

>So when I notice it's running low or even flat out dead I can start charging it
How about just buying powerbank that uses high quality cells with low self discharge rate?

>> No.60848773

A regular small car battery is around 12V * 40Ah ≈ 480Wh, but lead-acid batteries like to keep charged or else they sulfate and lose capacity so it's not recommended to discharge more than around half.

For comparison, regular power bank has around 6 or so 18650 cells which are 3.7V * 3Ah, or approx. 66Wh.

A 12v-5v step-down regulator is around 85% efficient. Most 5v devices, cameras etc charge at around an amp or two but don't draw much when they're fully charged, so assuming a reasonable 5V 4A (20W) total and accounting for inefficiency would charge 4 devices for around 10 hours to bring the car battery to around half charge.

A LCD voltmeter, 12v-5v stepdown and SPST switch is around $8 combined from China.

>> No.60848793

This charges only when the car is on or half-on (only the battery)
I'm looking for a solution that requires the car battery to only charge the "battery" when needed, and to use said battery to power 5V stuff even when the whole car is turned off.

I'm thinking of just getting a powerbank with a big display and put it somewhere logical that allows me to see the charge, but I really wanted something more discrete.

>> No.60848817


There are many sources of a constant 12v in a vehicle, and you can just switch the charger setup and voltmeter on and off.

>> No.60848826

Powerbanks have chips that do that for you. There's no reason to not leave it plugged in charging.

>> No.60848837

Again, I got the system mostly done, I just need a way to check the current charge of the powerbank even if its tucked away.

>> No.60848859

In that case crack open the case and measure the cell voltage directly

>> No.60848950

1. Dismantle it
2. Find the wires/traces that drive the low battery LED
3. Splice in your own wires
4. Use them to drive an indicator light naywhere of your choosing

>> No.60848973

Alternatively, assuming he's talking about an anker bank. He can crack off the front plate, cut the wires leading to the batteries, use the battery bank faceplate to plug into and use longer wires to hide the actual batteries somewhere in the car

>> No.60849047

train a neural network to figure out how many led lights are on given a picture of your power bank then set up a camera in front of your power bank

>> No.60849276

What about a small voltage monitor on the input and output side that shows mAh too?

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