UPS for arduino (high temp enviorment)

Hello,

TLDR- Need a UPS for my arduino that can withstand temps of up to 65 degrees

i want to make an alarm to remind me and my wife to not forget our baby in the car (not planning to but these thing happen).
The problem i have it with power to my arduino. i can connect to the cars 12V plug but after the car is turned off no power to my arduino.
i can use a power bank but i live in a hot area and i dont want the power bank to burst into flames when car is parked in the sun.

Im thinking about NiCd coin battery but i have no idea how to charge it properly.

any ideas?

thank you

If it does not need to be portable, just find a source in the car that's not turned off would be my suggestion. :slight_smile:

septillion:
If it does not need to be portable, just find a source in the car that’s not turned off would be my suggestion. :slight_smile:

I agree. The car alarm system comes to mind, as well as the interior lights, as well as, possibly, the car computer, all have continuous power.

Your car probably has a cell phone charger port. Use a battery for a cell phone and charge it while the car is running. Don’t need much current if you never leave the baby in the car.

Paul

If you have a memory problem, and the solution you come up with involves remembering to set alarms, whatever, then maybe a simple 'low-tech' solution is the answer, perhaps something as simple as a length of string tied to baby and you would help, and be more reliable/temperature independent, or string tied to baby and car keys, assuming you remember to lock car when leaving. Even a card on the dashboard, when baby is on board, may help. The problem seems to occur when a normal routine is disturbed - e.g. going to work, and then one unusual day you are asked to drop off baby to carer, and by the time you get to your workplace, you've forgotten, because you are on 'auto-pilot' driving to work. Eventually, babies become teenagers, then you'll need help!

Yes, there are continuously "hot" wires in a car. Probably about half of the "stuff" will turn-on with the key turned-off.

If you can get to and trace/follow the fuse-box wires you can check the voltages with the key off, then tap-into one of the hot wires. (You'll probably need to remove the fuses one at a time, and then you may have to re-set the clock and/or the security code on your car radio, has one.)

Or if you have a service manual and wiring diagram for your car, that's helpful.

Once you find the wire, a wire-tap like [u]this[/u] is handy for taping-into a wire without cutting it.

And, it will be a "cleaner" installation if you don't have to plug-into the power outlet!

maybe a simple 'low-tech' solution is the answer,

There was a TV news story about this recently and they suggested putting your purse, backpack, briefcase, phone, etc., in the back seat.

septillion:
If it does not need to be portable, just find a source in the car that's not turned off would be my suggestion. :slight_smile:

Thanks for the reply
that is what i did. but i want this to be portable so.... yeah.

Then I would go for simple NiMH batteries. If left in the heat for long times they might not life as long but they are not as critical as a Li-type battery. They are used in solar lights all the time which get blazing hot as well.

Smoke alarms use alkaline 9V batteries and have a low battery warning beep, this is very reliable tested
approach to this kind of problem and compatible with high temperatures.

eyasdef:
i want to make an alarm to remind me and my wife to not forget our baby in the car (not planning to but these thing happen).

What? :astonished:

Hi Paul, fwiw, I originally thought the same, who could forget a baby, but apparently it has happened with disastrous consequences. (do a search of 'baby left in car') Although I think it is extreme to want an electronic device to remind you, I bet those folk wish they'd been reminded. The problem becomes, however, when you rely on a gadgets, and it fails, or is not quite showing things relevant at the time - e.g hgv drivers following satnavs, etc.

raymw:
Hi Paul, fwiw, I originally thought the same, who could forget a baby, but apparently it has happened with disastrous consequences. (do a search of 'baby left in car') Although I think it is extreme to want an electronic device to remind you, I bet those folk wish they'd been reminded. The problem becomes, however, when you rely on a gadgets, and it fails, or is not quite showing things relevant at the time - e.g hgv drivers following satnavs, etc.

The easy solution, which no one seems to recognize, is to TURN THE DAMN RADIO OFF!!!!!! DO not listen to music or whatever while driving.

Paul

raymw:
Hi Paul, fwiw, I originally thought the same, who could forget a baby, but apparently it has happened with disastrous consequences. (do a search of 'baby left in car') Although I think it is extreme to want an electronic device to remind you, I bet those folk wish they'd been reminded. The problem becomes, however, when you rely on a gadgets, and it fails, or is not quite showing things relevant at the time - e.g hgv drivers following satnavs, etc.

Significant enough of a problem that there has been legislation proposed to require alarms in new cars Hot Cars Act of 2019

septillion:
Then I would go for simple NiMH batteries. If left in the heat for long times they might not life as long but they are not as critical as a Li-type battery. They are used in solar lights all the time which get blazing hot as well.

thanks for the reply.
that is what i thought as well. But i dont know how i go about using NiMH as UPS...

need a charging circuit i guess...

david_2018:
Significant enough of a problem that there has been legislation proposed to require alarms in new cars Hot Cars Act of 2019

That isn't going to get far. :roll_eyes:

Such an alarm would need to discern between a child, an animal, a baby concealed in a basket, a child concealed in a child seat, a child seat without the baby, and most difficult of all, the heap of stuff you always keep in the back seat.

They are simply joking! :astonished:

I also note that the vast majority of these situations would not involve forgetting that there is a child or animal in the car, but simply leaving them there for only a minute. :sunglasses:

NiMH are also quite forgiving when it comes to charging. They are fin with trickle charging for example. So a simple resistor to limit the (trickle) current would already be fine as a charging circuit.