Dashcam Back Up Battery question for the techs

[SteveRuss]

Hi guys

I recently installed a front and rear Dashcam in my car due to constant hit and runs whilst my car is parked. I've grown sick of the general lack of respect some bad drivers have for other people's property. My car is riddled with dents and scratches. None of which I am responsible for.

So. I installed a Thinkware F770 front and rear camera set up which has a parking mode which monitors movement and shock. If it detects either a bump or movement in front of either camera, it stores the previous 10 seconds and some seconds after the event.

This is great but to power itself, it does so off of the car battery. Cleverly, it has a voltage cut off in the software so you can set it to stop draining the battery at a certain voltage. I have mine set to 12.1vdc at the moment (still experimenting) and it seems to achieve around 12 hours from the cars four year old 75ah battery.

The question is as follows. You can buy a backup battery from from Celllink which seems like a sensible idea (you can piggy back an additional battery pack from them) but they are a shocking £170. Add the additional battery and you at over £300. This seems crazy..

I'm looking for an alternative as I don't feel there is enough technology for the money. Any ideas appreciated!!


Steve

 

[Nealh]

You could make up 18650 pack with BM but will still cost at least £75 for a meagre 4s 2p pack.

For your modest power draw how about a cheap option of one of these, no worries about using it for the car. Just needs charging every few days.
http://www.allbatteries.co.uk/battery/motorbike-battery.html

 

[Danidl]

Hi guys

I recently installed a front and rear Dashcam in my car due to constant hit and runs whilst my car is parked. I've grown sick of the general lack of respect some bad drivers have for other people's property. My car is riddled with dents and scratches. None of which I am responsible for.

So. I installed a Thinkware F770 front and rear camera set up which has a parking mode which monitors movement and shock. If it detects either a bump or movement in front of either camera, it stores the previous 10 seconds and some seconds after the event.

This is great but to power itself, it does so off of the car battery. Cleverly, it has a voltage cut off in the software so you can set it to stop draining the battery at a certain voltage. I have mine set to 12.1vdc at the moment (still experimenting) and it seems to achieve around 12 hours from the cars four year old 75ah battery.

The question is as follows. You can buy a backup battery from from Celllink which seems like a sensible idea (you can piggy back an additional battery pack from them) but they are a shocking £170. Add the additional battery and you at over £300. This seems crazy..

I'm looking for an alternative as I don't feel there is enough technology for the money. Any ideas appreciated!!

I
Steve

I applaud your common sense . I looked up the specs for the device and it draws 2.5watts from a 12v supply, this means 200mA . Halfords have 20amphr 12v batteries based on lead acid sealed gel . See it in their leisure or motorbike section at around 40£. If this is connected to the cigarette lighter socket , then it will charge while the car is in motion and be disconnected when power is switched off. From a charged state it will provide 100 hrs of operation. That's 4 days ...

 

[SteveRuss]

Thanks guys!

The lead acid battery idea is appealing to me. I don't want to use the cigarette lighting sockets (mine is live 24/7 anyways) but I could power it off of an 'acc' fuse from the board. I have a couple of fuse piggy backs spare anyways. Would that work? Hmm..

 

[Danidl]

Thanks guys!

The lead acid battery idea is appealing to me. I don't want to use the cigarette lighting sockets (mine is live 24/7 anyways) but I could power it off of an 'acc' fuse from the board. I have a couple of fuse piggy backs spare anyways. Would that work? Hmm..

A fully charged SLA battery of 12v will be at 13.6 to 13.8v and will go down to 11.8 when discharged. This 13v is the voltage present on the cigarette socket and or ACC rail in the fuse box The only concern is that the battery might draw excessive current when charging from a dead state, if the electrical resistance of the wire is too low.

This is probably counterintuitive but think about it for a minute.
.. You can protect against this by putting any electric bulb in series . Not an led type , just one of the old fashioned incandescent types. Halfords would have these in little holders with wired connection the type used for cabin or floor lighting.. the bulb won't even light up or at most a very dull red, but will effectively limit the maximum charging current. .. a useful safety feature.

 

[SteveRuss]

A fully charged SLA battery of 12v will be at 13.6 to 13.8v and will go down to 11.8 when discharged. This 13v is the voltage present on the cigarette socket and or ACC rail in the fuse box The only concern is that the battery might draw excessive current when charging from a dead state, if the electrical resistance of the wire is too low.

This is probably counterintuitive but think about it for a minute.
.. You can protect against this by putting any electric bulb in series . Not an led type , just one of the old fashioned incandescent types. Halfords would have these in little holders with wired connection the type used for cabin or floor lighting.. the bulb won't even light up or at most a very dull red, but will effectively limit the maximum charging current. .. a useful safety feature.

Thanks.

My concern with this the SLA at the moment is that I'm thinking I'd require a deep cycle leisure type battery as a standard led acid battery won't like being fully discharged then recharged all the time. Thoughts?

 

[Danidl]

Thanks.

My concern with this the SLA at the moment is that I'm thinking I'd require a deep cycle leisure type battery as a standard led acid battery won't like being fully discharged then recharged all the time. Thoughts?

..how often will the car be left for 4 days on the trot?. The rate of Discharge is very low. Not as low as the self discharge but pretty low. ,. It's true that a deep discharge one would be better , but it is your money. I don't think that a home brew 12 li ion pack is the way to go on cost and safety grounds.

 

[SteveRuss]

..how often will the car be left for 4 days on the trot?. The rate of Discharge is very low. Not as low as the self discharge but pretty low. ,. It's true that a deep discharge one would be better , but it is your money. I don't think that a home brew 12 li ion pack is the way to go on cost and safety grounds.

Well. For me, I go abroad working a fair bit and although I accept I am not expecting a 24/7 solution, I frequently leave my car for days on end and then often use it for short journeys for a week or two. In my situation, I think the battery will take a battering. I probably should have pointed that out before.

I left my car outside of my house yesterday around 4pm and got in today at 9am and was surprised that the camera was still actively in parking mode. I had just driven from London for three and a half hours (Friday traffic!) so the battery was fully charged.

I suppose the solution I am mainly looking for is to avoid draining my car battery and ruining its lifespan, whilst extending the camera's operability to more than I suppose is acceptable for most people.

To extend. The biggest reason I bought the camera is to get the lazy early morning driver (we are at the business end of the local school run) that hits my car then runs for it. 9am was a surprise to me but previously i've noticed it die at around 6-7am which misses the targets i'm going for. 24hrs would do me. Or at least 20hrs!

I just wish they did a 200ah battery for my car. The badest I can find is 85ah.

Cheers...

 

[Danidl]

Well. For me, I go abroad working a fair bit and although I accept I am not expecting a 24/7 solution, I frequently leave my car for days on end and then often use it for short journeys for a week or two. In my situation, I think the battery will take a battering. I probably should have pointed that out before.

I left my car outside of my house yesterday around 4pm and got in today at 9am and was surprised that the camera was still actively in parking mode. I had just driven from London for three and a half hours (Friday traffic!) so the battery was fully charged.

I suppose the solution I am mainly looking for is to avoid draining my car battery and ruining its lifespan, whilst extending the camera's operability to more than I suppose is acceptable for most people.

To extend. The biggest reason I bought the camera is to get the lazy early morning driver (we are at the business end of the local school run) that hits my car then runs for it. 9am was a surprise to me but previously i've noticed it die at around 6-7am which misses the targets i'm going for. 24hrs would do me. Or at least 20hrs!

I just wish they did a 200ah battery for my car. The badest I can find is 85ah.

Cheers...

... Another serious contender would be to get a 10w to 15w solar panel and in combination with your 20amp HR battery would augment the power . The solar panel inside the car on the dashboard or rear window , would average perhaps 3w to 4 w...

 

[SteveRuss]

... Another serious contender would be to get a 10w to 15w solar panel and in combination with your 20amp HR battery would augment the power . The solar panel inside the car on the dashboard or rear window , would average perhaps 3w to 4 w...

That's not a bad idea

I may seriously look in to that. How would you guys wire this all up? I would have to keep the ACC wire from the camera in the same place as it triggers either parking mode or driving mode. The permanent live would have to come directly from the bike battery via an inline fuse (probably 5amp or so). I would want the battery under the bonnet ideally but i'm not sure how to configure/wire it to charge.. Any ideas received with thanks!

 

[Danidl]

That's not a bad idea

I may seriously look in to that. How would you guys wire this all up? I would have to keep the ACC wire from the camera in the same place as it triggers either parking mode or driving mode. The permanent live would have to come directly from the bike battery via an inline fuse (probably 5amp or so). I would want the battery under the bonnet ideally but i'm not sure how to configure/wire it to charge.. Any ideas received with thanks!

.with a sufficiently large solar panel, there would be no need to buy another battery and the solar panel could augment the power stored in your conventional battery.
My suggestion is to get say an 18v open circuit voltage solar panel of say 15 watt minimum , and connect it via a single in series silicon diode say 3amp rating and an inline fuse of 5amp and connect it directly to the main battery or perhaps at the ACC connection if this is unswitched. The fuse should be very close to the battery live so that safety is maintained. The diode is to prevent the battery discharging through the solar panel.
While 18v is more than the 13.6v of a fully charged battery, the current is so limited that it will only charge the battery to its 13.6
This is why it is useful to discuss problems, .. a solution emerges as more facts are considered.

 

[SteveRuss]

.with a sufficiently large solar panel, there would be no need to buy another battery and the solar panel could augment the power stored in your conventional battery.
My suggestion is to get say an 18v open circuit voltage solar panel of say 15 watt minimum , and connect it via a single in series silicon diode say 3amp rating and an inline fuse of 5amp and connect it directly to the main battery or perhaps at the ACC connection if this is unswitched. The fuse should be very close to the battery live so that safety is maintained. The diode is to prevent the battery discharging through the solar panel.
While 18v is more than the 13.6v of a fully charged battery, the current is so limited that it will only charge the battery to its 13.6
This is why it is useful to discuss problems, .. a solution emerges as more facts are considered.

Well. As an experiment, (I know this may not work as an ideal solution) I've bought a £20 7.5watt panel that will fit on the dash board temporarily. If it doesn't extend the operation substantially (or even noticeably) then I'll use it elsewhere.

I couldn't find a fair sized 15watt one but I'll keep searching. I agree that this may have been the simple solution that may work out. It has a diode built in by the way.

Cheers.

 

[Danidl]

Well. As an experiment, (I know this may not work as an ideal solution) I've bought a £20 7.5watt panel that will fit on the dash board temporarily. If it doesn't extend the operation substantially (or even noticeably) then I'll use it elsewhere.

I couldn't find a fair sized 15watt one but I'll keep searching. I agree that this may have been the simple solution that may work out. It has a diode built in by the way.

Cheers.

Well two of those panels joined electrically in parallel will give you 15 w peak. .. since they have blocking diodes , this is feasible.

 

[SteveRuss]

Well two of those panels joined electrically in parallel will give you 15 w peak. .. since they have blocking diodes , this is feasible.

Yep. Def something to consider. I'll let you all know how it works out.