Outdoor WiFi security camera bodge question

[DonkeyApple]

I have some Kasa outdoor cameras that run from USB sockets so I'm assuming 5v.

I'd like to use one on an outhouse that has no mains and is a bit too far to bother running mains to.

I've a cheap solar cell in the post that I was going to use to just trickle charge things like the mower battery and the toy cars. This should work as these are only used in summer anyway.

It's just a very basic 30w panel: https://www.amazon.co.uk/gp/aw/d/B0D8KXYPJ4?ref=pp...

I've also some left over 12v to 5v USD converters from a car project. And a car battery sitting in the garage.

So, I could quite easily plumb the solar trickle charger to the car battery and take a USB feed from that which should power a wifi camera.

I'm not very good with the maths around current draws etc, in fact, I'm pretty clueless so the main question that I have is how likely is such a set up to work in winter when the amount of solar getting put into the battery is going to be significantly reduced and the demand from the camera at its peak?

[DonkeyApple]

From what I can fathom the camera is 6 watts at 5 volts so draws 1.2 amps which in turn means it would last about 24 hours on a 30ah battery? Is that right?

And a 30w panel generating 12v would, at absolute best deliver 2.5ah and realistically for barely 12 hours?

[Mazinbrum]

Just get the Blink cams, very good and cheap as chips.

[DonkeyApple]

Mazinbrum said:

Just get the Blink cams, very good and cheap as chips.

Yup but I have these already and they work within the same app as the other stuff.

[Baldchap]

Lots of battery cams exist. The Home Assistant will tell you whether you can put them all in the same app, rather than burn your house down.

[wombleh]

Your calcs look right for those numbers but they seem a bit high for a USB camera. Our eufy ones last about 3-6 months on a charge from their internal battery that I think is about 7ah.

For a few months around xmas in the UK, you may find very little generated by the solar panel, so prob need to be manually charging for a while.

[DonkeyApple]

wombleh said:

Your calcs look right for those numbers but they seem a bit high for a USB camera. Our eufy ones last about 3-6 months on a charge from their internal battery that I think is about 7ah.

For a few months around xmas in the UK, you may find very little generated by the solar panel, so prob need to be manually charging for a while.

That was my thinking just on the basis of how long a car batter lasts running other things.

It draws 5v and the literature says 6 watts which equates to 1.2A. The 12v to 5v converter will draw a bit and the battery isn't going to be mint. My simple calcs, if correct, imply it's not likely to work well on the 30 watt basic panel.

[wombleh]

Wonder if it’s 6watts maximum but typically much lower usage.

Even if the camera isn’t very efficient, your battery and panel are way bigger than the ones on similar products for sale.

[DonkeyApple]

wombleh said:

Wonder if it s 6watts maximum but typically much lower usage.

Even if the camera isn t very efficient, your battery and panel are way bigger than the ones on similar products for sale.

Yup, again, that was something that I pondered as the company that made these cameras also makes the Tapo brand and their battery powered ones which are, as you say, using a smaller set up. But, the difference appears to be enormous as in magnitudes.

[Nigel_O]

I have several Eufy battery cameras. They have a couple of 6.7mAh 18650 batteries in them and they last for a couple of months on a charge.

Surely a single camera powered by a car battery (even a small one) is going to last for much longer, unless it’s constantly transmitting

[Gladers01]

DonkeyApple said:

Yup, again, that was something that I pondered as the company that made these cameras also makes the Tapo brand and their battery powered ones which are, as you say, using a smaller set up. But, the difference appears to be enormous as in magnitudes.

Chances are the camera will be drawing less than 1 amp from the 5v supply, the only way of knowing is to measure the current drawn using a basic ammeter in series with the 5v supply and it would also help to charge the car battery fully for a head start.

[Alex_225]

I have a Eufy camera set up and the cameras I use have solar panels built into them but you can get panels that have a dedicated 5v output for cameras.

This one isn't too pricey: https://www.amazon.co.uk/Compatible-Eufycam-Charge...

[DonkeyApple]

Alex_225 said:

I have a Eufy camera set up and the cameras I use have solar panels built into them but you can get panels that have a dedicated 5v output for cameras.

This one isn't too pricey: https://www.amazon.co.uk/Compatible-Eufycam-Charge...

Thanks. The key is that I have all the parts but was just trying to work out if the 24/7 drain of the camera was going to defeat the basic 12v 30w panel that is in the post for keeping the toylander and mower batteries topped up.

[DonkeyApple]

Gladers01 said:

Chances are the camera will be drawing less than 1 amp from the 5v supply, the only way of knowing is to measure the current drawn using a basic ammeter in series with the 5v supply and it would also help to charge the car battery fully for a head start.

It's been running off a power pack since 3pm and the pack is still displaying full bars so it looks like that may be the case.

If so then the 7ah spare mower battery will run it ad infinitum with the solar trickle charger sitting on the other side.

[silentbrown]

DonkeyApple said:

From what I can fathom the camera is 6 watts at 5 volts so draws 1.2 amps which in turn means it would last about 24 hours on a 30ah battery? Is that right?

Almost certainly not!

The eufy solocam units I have use about 100milliamp hours per DAY, so about 0.05 amps continuous,and that's at 5V, I believe.

So your 12V 30aH car battery would power one of those for around two years, without solar trickle charging.

[eliot]

you also need to consider that a 12v battery is considered flat at 10.5v - if you let something run it down to zero volts you are essentially ruining the battery

Edited by eliot on Wednesday 4th June 23:22

[DonkeyApple]

silentbrown said:

Almost certainly not!

The eufy solocam units I have use about 100milliamp hours per DAY, so about 0.05 amps continuous,and that's at 5V, I believe.

So your 12V 30aH car battery would power one of those for around two years, without solar trickle charging.

I think this is correct. I don't know the power of the pack I used but the camera was grafting all night recording the rain water coming off the roof and the pack still shows one of its 4 bars.

I reckon this'll work with just a 7ah or 10ah mower battery and the solar trickle charger, even on short winter days.

So the next question would be, can I legitimately piggy back the toy car batteries off the 7ah battery to trickle charge those occasionally or is it not clever to connect a pair of series 30ah batteries to a 7ah one?

Edited by DonkeyApple on Thursday 5th June 08:31

[Gladers01]

DonkeyApple said:

I think this is correct. I don't know the power of the pack I used but the camera was grafting all night recording the rain water coming off the roof and the pack still shows one of its 4 bars.

I reckon this'll work with just a 7ah or 10ah mower battery and the solar trickle charger, even on short winter days.

So the next question would be, can I legitimately piggy back the toy car batteries off the 7ah battery to trickle charge those occasionally or is it not clever to connect a pair of series 30ah batteries to a 7ah one?

Edited by DonkeyApple on Thursday 5th June 08:31

Should be Ok as long as the voltage is still 12v when piggy backed or connected in parallel, if the 30ah 12v battery was connected in series with another of the same type the voltage would double to 24v with the same current available, if connected in parallel still 12v with double the current available, in your case keep them in parallel as in positive to positive and 0v to 0v.

If using the 30ah in parallel with 7ah the total will be 37ah as long as the voltage is the same at 12v.