Solar power.

[ASt85]

Originally Posted by rxtian

Just to let you know - it is possible for the socket to power things, but it to be impossible to charge the battery through the socket - there can be a diode or mosfet in circuit to prevent reverse current flow.

I'm afraid that is not correct for the rear cargo area of the P1, P2 or P3 S60's, V70's, S80's, 90's or XC90's as there is no diode or mosfet used in the circuitry for the cargo area power point which would prevent reverse current flow.

The only exceptions are those vehicles in which a Volvo CD multichanger has been retrofitted and use the cargo area power socket +ve connection to power them.

[Clan]

Originally Posted by ASt85

I use solar battery maintainers that I bought from Aldi which are quoted as 6W output and work extremely well through the side windows of both my C70 and V70.

Even with the alarms left on, there is always full battery power available to spin the starters even after not starting for three months of more. Even on an overcast winter's day the output is above that quoted below. They are diode protected so you do not have to disconnect them if you use the car.
ALDI
6W(nominal) 12V Brand Auto XS - Dimensions: 50 x 35 x 1.5cm (approx.)
https://www.aldi.co.uk/solar-battery...12551262369400 which apparently is no longer available which is aldi speak for they'll be re-stocking it later in the year!
NB Guarantee/Warranty
3 Years
Suitable For Leisure vehicles up to 200Ah, large cars and 4x4 vehicles, motorcycles, golf trolleys, jet ski's, vans and boats.

HALFORDS
Halfords version is made by the same company and currently retails @ £39
https://www.halfords.com/motoring/ba...ah-196489.html

If you run a search for "solar battery maintainer 12v 6w" you should be able to source it for around tha Aldi price which was around £25 last year....NB it was only £11.99 in 2018!!

the solar panels you get in aldi etc are useless , 1/2 watt or even 1 watt barely covers the drain let alone adds a charge .
You being able to start it after 3 months is normal with a good battery , Volvo stipulate that new cars in storage be charged every 3 months .. They have just issued a bulletin to say charge the battery every 2 weeks in this alarming climate we are in at the moment .

you would need one of those solar panels you have on the roof of a house to provide 10A in the sun at the very least .. about £110 on ebay ... + the control regulator of course ..

[Spike56]

Now I'm just confused 😂

[Spike56]

There's a difference between charging and maintaining the battery though. I only need maintenance. I think I'll go with the solar system, through the boot socket and the occasional drive, and hope some scroat doesn't steal it!

[ASt85]

Originally Posted by Clan

the solar panels you get in Aldi etc are useless , 1/2 watt or even 1 watt barely covers the drain let alone adds a charge .
You being able to start it after 3 months is normal with a good battery , Volvo stipulate that new cars in storage be charged every 3 months .. They have just issued a bulletin to say charge the battery every 2 weeks in this alarming climate we are in at the moment .

you would need one of those solar panels you have on the roof of a house to provide 10A in the sun at the very least .. about £110 on ebay ... + the control regulator of course ..

I am sorry to disillusion you Clan but on this rare occasion you are not correct; the panels are marketed as battery maintainers and are primarily designed for caravan leisure battery maintenance - on a cloudy midwinter day the output when connected to the battery via the rear cargo power point gives a pd of 14.2 volts with a current "supply" of 0.5amperes i.e. output of the order > 6W - on a bright summer's day this rises to over 23 volts with the current measured as 0.9amperes i.e. of the order of > 11W when connected to the battery via the rear cargo area power point - I often do not use any of the cars on the drive for several weeks - the alarms are always left on - they start first turn of the key with barely any perceptible lag between turning the key before the engine is running. The batteries behave like new fresh fully charged batteries. The V70's battery is the 2004 original. Not too shabby for a 16-year-old battery.

The solar panels mentioned above are battery maintainers designed for caravan leisure battery maintenance and they really do work, if they didn’t, I would not have bought a second and then a third for each car on the drive.

I would not recommend any appliance where the performance was not at least within the quoted parameters - these panels exceed the quoted specs.

The oldest panel has been in use for over three years and is currently used to maintain the battery on my 2005 C70..........the car did a total of 140 miles between February 2019 and February 2020 when it started first turn of the key to go for an MOT not having been used since August 2019, in the intervening period, the only electrical power input was from the solar panel.

[rxtian]

Originally Posted by ASt85

I'm afraid that is not correct for the rear cargo area of the P1, P2 or P3 S60's, V70's, S80's, 90's or XC90's as there is no diode or mosfet used in the circuitry for the cargo area power point which would prevent reverse current flow.

The only exceptions are those vehicles in which a Volvo CD multichanger has been retrofitted and use the cargo area power socket +ve connection to power them.

Calm down mate - just pointing out the possibility so people should check rather than just chucking a plug in and thinking job done!

[ASt85]

Originally Posted by rxtian

Calm down mate - just pointing out the possibility so people should check rather than just chucking a plug in and thinking job done!

Totally calm, relaxed and not at all ruffled, your point was well made

[Clan]

Originally Posted by ASt85

I am sorry to disillusion you Clan but on this rare occasion you are not correct; the panels are marketed as battery maintainers and are primarily designed for caravan leisure battery maintenance - on a cloudy midwinter day the output when connected to the battery via the rear cargo power point gives a pd of 14.2 volts with a current "supply" of 0.5amperes i.e. output of the order > 6W - on a bright summer's day this rises to over 23 volts with the current measured as 0.9amperes i.e. of the order of > 11W when connected to the battery via the rear cargo area power point - I often do not use any of the cars on the drive for several weeks - the alarms are always left on - they start first turn of the key with barely any perceptible lag between turning the key before the engine is running. The batteries behave like new fresh fully charged batteries. The V70's battery is the 2004 original. Not too shabby for a 16-year-old battery.

The solar panels mentioned above are battery maintainers designed for caravan leisure battery maintenance and they really do work, if they didn’t, I would not have bought a second and then a third for each car on the drive.

I would not recommend any appliance where the performance was not at least within the quoted parameters - these panels exceed the quoted specs.

The oldest panel has been in use for over three years and is currently used to maintain the battery on my 2005 C70..........the car did a total of 140 miles between February 2019 and February 2020 when it started first turn of the key to go for an MOT not having been used since August 2019, in the intervening period, the only electrical power input was from the solar panel.

They dont sell things like that in Halfords or ALDI though .. how much was your panel? I need a modern monocrystaline cell 1600 x 1000 mm to supply 9A to charge a 12v battery , about £120 What i described was rubbish you buy in accessory shops for £10 or £20 or even more .

[MacV50]

Originally Posted by Spike56

Time for someone to create a solar panel sunroof?

Already been done. I bought a new A4 in 2004 that had that as an option. Nor sure if it charged the battery but it ran the fans to cool the car on hot days

[Spike56]

Another missed patent!