Solar powered Car Battery Charger.

[Benchwayze]

Apparently one can leave the things connected more or less permanently. Has anyone used one of these things? Would welcome any pointers on buying one. (May car isn't getting much use and the battery is draining too easily!)

Thanks in anticipation

Cheers...

 

[Monkey Mark]

They can be handy. And yes you can leave them on permanently. The lower power ones won't put enough out to damage a battery and the higher powered ones have charge controllers.

A wet cell battery will lose about 0.3 percent each day through natural discharge. So for a 100ah battery the panel would need to provide a minimum of 0.33amps to maintain. Add say another 2 amps for a car alarm. So 2.33amps discharge per day.

Allow for a crystalline panel facing south and un-shaded to supply for a maximum of 2 hours of optimum output in the winter, and 4 to 5 hours in the summer. If the panel is going to be placed in the car, note that any window could reduce the amount of light reaching the solar panel.

To find the Amperage output, divide the panels wattage by 17.

So a 20 watt panel should produce:-

20 watts divided by 17 = 1.18amps. per hour in optimum conditions.
In the winter approximately 2.36 amps will be supplied over the course of a day based on 2 hours of optimum output per day (more in summer), just enough to keep a 100Ah battery charged and to power the alarm.


Avoid anything less than 20w otherwise you're wasting your money.

 

[DiscoStu]

I'm not sure I quite agree with your maths. I have a 10watt panel and that more than capable of keeping my car topped up. I know people that have 5w panels and that's enough to keep them charged 2amps for an alarm seems like a lot.


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[Monkey Mark]

I'm not sure I quite agree with your maths. I have a 10watt panel and that more than capable of keeping my car topped up. I know people that have 5w panels and that's enough to keep them charged 2amps for an alarm seems like a lot.


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I use them primarily on a caravan and have dealt with quite a few others. Your findings may be different but that's what i usually base things on. Last time i looked the price difference from 10w to 20w wasnt much.

 

[Wildman]

To find the Amperage output, divide the panels wattage by 17.

So a 20 watt panel should produce:-

20 watts divided by 17 = 1.18amps. per hour in optimum conditions.
In the winter approximately 2.36 amps will be supplied (more in summer), just enough to keep a 100Ah battery charged and to power the alarm.


Avoid anything less than 20w otherwise you're wasting your money.

in the winter output will be more like .023 milliamps How you come up with a higher figure for winter than summer I have no idea.

 

[Monkey Mark]

To find the Amperage output, divide the panels wattage by 17.

So a 20 watt panel should produce:-

20 watts divided by 17 = 1.18amps. per hour in optimum conditions.
In the winter approximately 2.36 amps will be supplied (more in summer), just enough to keep a 100Ah battery charged and to power the alarm.


Avoid anything less than 20w otherwise you're wasting your money.

in the winter output will be more like .023 milliamps How you come up with a higher figure for winter than summer I have no idea.

My apologies, the 2.36 was based over a day not per hour. I will alter to clarify.

 

[blackrodd]

You don't say if the car is outside, as it would be easier indoors for this idea.
My kawasaki hibernates in winter, usually from October 'til March,
To keep the battery maintained and charged, I use an Oximate, which works very well Made by Oxford.
A copy of the original and more expensive Optimate, I've had this for 10, or 12 years
These things actually use and maintain you're battery, in my opinion far better than any solar stuff so far,
And I imgine you're battery is expensive too!
Here's a link,-
Rodders

http://www.amazon.co.uk/oxford-oximiser ... B002QVCB80

 

[nev]

My (recently sold )old tractor had a car battery on it. I could leave it 6 months between starts, outside in all weathers, and never had an issue. If your car battery is discharging enough over a month or two to prevent starting I would suspect that the battery is on its way out and may need replacing anyway.
Just a thought.

 

[Wildman]

modern vehicles have a constant draw that the tractor would not.

 

[DiscoStu]

CTech are widely regarded as "The" charger of choice in the Land Rover world, however Lidl and Aldi often have one that looks the same and I've bought one of those and found it to be excellent.


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[Benchwayze]

Thanks for the info folks. I think I will invest. My son put me onto these, so I'll let him go and sort one out! (He might even offer to treat me! :lol: ) Yeah, and pigs might take to the wing!

Nev,

I am of a mind that the battery might need replacing. I always buy the biggest I can get, but the problem is the car just hasn't had a lot of use since my wife became ill. We just can't find the time to get out and about like we did. Plus, I recently had a suspected TIA so it's likely to be another few weeks before I can get the Doc to examine me, to see if I am okay to drive. Come that lucky day I'll have a new battery and use one of these chargers.

Rodders..

Why would I want to put my car in a garage? :lol:
Too much woodwork machinery and tools in there! :lol:
Besides which. if I did get the car in there, there isn't enough width to open the car door to get out of the vehicle! Even a Mini would find it a tight squeeze! One advantage is the car never rusts outside; condensation never gets a chance! (hammer)

I am much obliged to all for the contributions.

Regards

 

[Benchwayze]

You don't say if the car is outside, as it would be easier indoors for this idea.
My kawasaki hibernates in winter, usually from October 'til March,
To keep the battery maintained and charged, I use an Oximate, which works very well Made by Oxford.
A copy of the original and more expensive Optimate, I've had this for 10, or 12 years
These things actually use and maintain you're battery, in my opinion far better than any solar stuff so far,
And I imgine you're battery is expensive too!
Here's a link,-
Rodders

http://www.amazon.co.uk/oxford-oximiser ... B002QVCB80

Looking at conflicting reviews, I wonder if the counterfeiters have been busy?

 

[blackrodd]

You don't say if the car is outside, as it would be easier indoors for this idea.
My kawasaki hibernates in winter, usually from October 'til March,
To keep the battery maintained and charged, I use an Oximate, which works very well Made by Oxford.
A copy of the original and more expensive Optimate, I've had this for 10, or 12 years
These things actually use and maintain you're battery, in my opinion far better than any solar stuff so far,
And I imgine you're battery is expensive too!
Here's a link,-
Rodders

http://www.amazon.co.uk/oxford-oximiser ... B002QVCB80

Looking at conflicting reviews, I wonder if the counterfeiters have been busy?

I think the first problem is people buying the cheaper model of these and not taking into account the amps of the battery to be maintained, Buying one will save you're battery that has irregular use.
A new battery for my 57 plate Kwakka is £48. so it's not small in power having an alarm and immobiliser built in.

I thought it quite possible you would have a double garage as well as the workshop!
Rodders

 

[Benchwayze]

Rodders.

Double Garage! I have space for one at the right side of the property, but my house is a corner residence. The planners said it would impede the view of the road, as drivers leave the grove! So I should be so lucky! :roll: :lol:

The battery I would need for my Volvo S90 is a snip at £90.00. (That's a Bosch battery. Not sure what kind of rep they have, if any. ) :?: