Any one else using solar panels for parking mode dash cams?

[StevieRuss]

After hardwiring a Thinkware F770, I've been experimenting with how long my car battery can keep the cams (front and rear) running before it switches off. I've set the camera to cut off at 12.1vdc

So far, I've managed around 12-14hrs on a fully charged battery (after motorway journey for instance) before it stopped.

I bought a 7.5watt solar panel which either wires to the battery or the ciggy lighter. I've been using it with the ciggy lighter option so far (yes it is a permanent live) and I returned to my car after 17 hrs and it was still working.

I'll have to do a full test to when it actually cuts off but so far a marked improvement. A 15watt one could be the final solution but I haven't found one at the right size for the dashboard.

 

[flip9]

A 15watt one could be the final solution but I haven't found one at the right size for the dashboard.

Just make sure its regulated to 12-14v and has a diode to stop the battery back flowing. These are usually sold as maintenance trickle chargers.

Do not connect an unregulated solar panel as it will have an open voltage of 19v+

 

[StevieRuss]

Just make sure its regulated to 12-14v and has a diode to stop the battery back flowing. These are usually sold as maintenance trickle chargers.

Do not connect an unregulated solar panel as it will have an open voltage of 19v+

Hi

It peaks at around 18vdc which is fine for a standard car battery (with such a low current potential). 12vdc would be too low to be useful. Once in circuit, it drops anyways. It's actually sold as a car maintenance battery and consequently has a silicone diode (a kind of electrical version of a non-return valve for those reading that don't know what a diode is. It stops reverse drain if there is no light and the solar panel is still connected)

All good points though, that I should have ideally included in my post.

Cheers

 

[flip9]

I hope the 18v is the peak rating of the panel and not the actual charging voltage. Charging at 18v is not fine for a car battery and it will also be passed on to the electronics of your car.

Anyway ive been looking at attaching my 120w solar panel to the roof of my car. Its currently connected to my Auxiliary battery and i have to fold it out to get a charge.

I was looking these 2.5mm flexible solar panels now which can be mounted to the outside of the car.

https://www.ebay.com.au/itm/391591153311

 

[StevieRuss]

I hope the 18v is the peak rating of the panel and not the actual charging voltage. Charging at 18v is not fine for a car battery and it will also be passed on to the electronics of your car.

Anyway ive been looking at attaching my 120w solar panel to the roof of my car. Its currently connected to my Auxiliary battery and i have to fold it out to get a charge.

I was looking these 2.5mm flexible solar panels now which can be mounted to the outside of the car.

https://www.ebay.com.au/itm/391591153311

100watts is more than I need personally but as a support for a leisure battery then great!

Cheers for the link. I'm in the early stages of finding a more powerful solution so I'll read in to this further.

The 18vdc is peak but once in circuit with a 85ah lead acid, it balances out well. If the voltage was too low, it would just sag and be useless.

Again. The one bought is sold as a maintenance panel for keeping SLA batteries in good shape (to stop natural drain in batteries that are used seasonally mainly). It's kind of perfect for my experimentation.

Let me know how your 100watt panel idea works out though.

 

[flip9]

I got a fridge in the back so i need all the power.

If your just running a dashcam, theres no point of going higher than 15w.

The F770 only draws 270mA on 2CH parking mode. A 15w panel can already output 2-3 times that, any more will be a waste.

 

[StevieRuss]

I got a fridge in the back so i need all the power.

If your just running a dashcam, theres no point of going higher than 15w.

The F770 only draws 270mA on 2CH parking mode. A 15w panel can already output 2-3 times that, any more will be a waste.

Quite right. In an ideal world, if the solar panel is peaking then it's more than twice the current requirements for the cams from a 7.5watt panel. That said, considering our general light levels (in the Uk), the 15watt should be the ideal minimum.

I'll keep monitoring and reporting my findings. I just thought that as a lot of people are seemingly investing hundreds of pounds on bespoke low capacity lithium powered battery technology (cellink B as an example) that their solution maybe be easier than they'd have thought. I could be wrong but I'm going with it.

Cheers for your input !!

 

[flip9]

I just thought that as a lot of people are seemingly investing hundreds of pounds on bespoke low capacity lithium powered battery technology (cellink B as an example)

Yeap, solar is a feasible choice. It just isn't suited for everyone since it doesn't work in cloudy days or underground car parks.

 

[StevieRuss]

Yeap, solar is a feasible choice. It just isn't suited for everyone since it doesn't work in cloudy days or underground car parks.

Cloudy days are not always so bad. Underground car parks then that's the point where my idea falls over

 

[SawMaster]

An unloaded output voltage will drop when applied to a load such as a car battery, so as long as you don't power anything directly from the panel it should be OK to use. Once I get all my other projects done, I'm going to add solar to the top of my van since I don't use that space for cargo That could be years away though, just have to see

Phil

 

[flip9]

Phil if your ever having a look at solar MPPT controllers for your van, have a look at the EPever Tracer 2210A. Its fantastic value for money, true MPPT and the charge parameters can be programmed.

I upgraded the cheapo PWM controller that came with solar panel to the Tracer last year and its been working well.

 

[jy1129]

Just curious, but how has the 7.5W solar panel been working out? Did you wire it to the fuse box? I just ordered two 18V 7.5W solar car battery chargers and solar controllers for my car and suv that have the QVIA R975 dual dash cam with parking mode. I read that the power consumption is 340mA (4.5W) so I hope the panel will be enough to maintain the car battery's charge while powering the dual dash cam. I don't drive often so the dash cam usually turns off after it reaches the preset minimum voltage level.

 

[dctester]

Anyone have success?

I installed 7.5w with regulator and discovered UK weather too cloudy, voltage too low.

 

[Nigel]

Anyone have success?

I installed 7.5w with regulator and discovered UK weather too cloudy, voltage too low.

A dashcam requires around 2 watts on average, some are a little more, some a bit less.

2 watts * 24 hours = 48 Wh per day.

At this time of year we only have 6 hours of usable daylight, so 48/6 = 8W on average during daylight hours.

If you are not pointing the solar panel directly at the sun then double the wattage, if you put it inside the car then the glass will remove a lot of the energy so double it again, unless every day is bright sunshine in a cloudless sky from dawn to dusk then double it again. 8 * 2 * 2 * 2 = 64W

Some weeks have almost no sunshine so unless your battery is big and can hold out for over a week then double it again. 64 * 2 = 128W

So a 128W panel should keep you going continuously on solar power, but if you drive you car occasionally to charge the battery then you can make do with less.

Sunshine in November in the UK is not a reliable source of power!

 

[dctester]

Nigel, thanks for your calculations.

I do drive the car daily on weekdays, about 30 mins to 1 hour of driving.

I am hoping to use it to top it up. I measure the voltage a couple of times this week, the voltage are mostly low with the cloudy weather. I am using a solar charge controller at these voltage I don’t think it is charging the battery at all.

It has made a difference as my start stop now working in the morning, but car battery voltage still quite low.

I don’t want a big panel on my car, that’s why I bought the 7.5w, it fit neatly on small side window at the cargo area.

The only thing I could think of now is maybe buy two of these panels and fit in series to up the voltage. It might just fit in the small side window.

Does anyone know if a MPPT charge control would work in such a low energy panels?

By the way I have a big car (xc60) with F800 pro dual cameras.

 

[Nigel]

If you drive your car daily then the solar panel should not be required, the car alternator should be able to replace the 48Wh within 20 minutes. The start-stop should disable until the battery is charged back up to reasonable voltage.

When you say the voltage is low, what do you mean by low? You probably have an AGM battery for the start-stop system that is quite happy to go down to 11.8 volts when measured with the 2W load of a dashcam on it, that doesn't indicate a problem, just normal operation...

The only thing I could think of now is maybe buy two of these panels and fit in series to up the voltage. It might just fit in the small side window.

Does anyone know if a MPPT charge control would work in such a low energy panels?

Do not connect them in series, if it is a 12 volt panel then 2x 12 = 24 volts, which is enough to fry you £2000 car central computer, and most 12 volt solar panels will produce closer to 18 volts at full power and even more when the car battery is full! 18 volts * 2 = 36 volts = hydrogen released from your car battery followed by a big explosion
They should be connected in parallel.

An MPPT charge controller will work fine, and avoid ever overcharging the battery, and produce maybe 50% more power from the panel since it is then able to work at around 18 volts instead of 12 volts, although some solar panels intended for cars already have some electronics built in which may not be compatible. You can use a cheap one like this if you set it correctly before connection: Example

 

[dctester]

I think my problem is I don’t necessary drive over the weekend, potentially that’s 63 hours.

When I say low voltage I mean the car start warning me of low voltage and the power tailgate stop working, start stop stop working.

Since I installed the solar panel with a controller, I not had this problem. But my cigarette lighter volt meter is currently only showing 11.8v when engine off. I read voltage is suppose to be higher. I have an EFB.

I know it’s a bad idea to install two in series directly to car, I was thinking installing two in series with a MPPT controller, but I hear the EPEver MPPT controller don’t work with less then 10watts.

 

[dctester]

I just double check the voltage with a fluke multimeter it showing 12.2v. I think the cigarette one is inaccurate.

 

[Nigel]

I think my problem is I don’t necessary drive over the weekend, potentially that’s 63 hours.

The best solution is probably to install a low voltage cutoff for the dashcam so that it doesn't drain the battery too low however long you leave it. Even with a big solar panel the battery is not going to last forever during the winter, as long as it lasts overnight then you will have coverage most of the time and hopefully the trouble makers will have a day off on Sunday!

 

[dctester]

Thanks for your advice, I just checked my dashcam is set to cut off at 12.3v, I guess thats why my battery is sitting at 12.2v.

What I don't understand is why it didn't cut off previously, causing low voltage warning.

I will do more testing, if I find anything interesting I wll post an update.