Solar trickle charger for car battery

ajb69

Hi all,

I recently broke my arm so driving is off the menu for the next few months. I've got a 62-plate Mondeo, and am a little worried that the battery will be flat by the time it can next be driven -no one else is insured on it so I'm the only possible driver.

The car is parked on the street and not near any electricity, so I was looking at a solar battery charger like this:

http://www.amazon.co.uk/Solar-Battery-Charger-ideal-Caravans/dp/B000R0UBT8/

I'd have to use the cigarette lighter plug both for security and because there's no way I can open the bonnet with a broken arm anyway!

I wondered -

1/ Will it actually work? Or do all the fancy electrics (start/stop, keyless ignition etc) on modern cars mean you can't charge them this way?
2/ The Mondeo gets too clever by half and cuts off power to the cigarette lighter 15 mins after the engine is turned off - caught me out when charging my phone from it a few times! I'm guessing this will stop the charging working as well? Is there any way around this - does anyone have experience of Mondeos...?

thanks all,

drew

Marktheshark

The fuse for aux power has a double sized slot, move the fuse up to the other hole of the 3 terminals and it will stay live.

ajb69

Many thanks - sorry to be dumb, so that should be fuse FA6 in the boot, rather than F19 in the glovebox (or wherever the central fuse box is)? i'm going off here:

http://www.fordwiki.co.uk/images/d/da/Mk4_Fuse_and_Relay_Information_-_printable.pdf

Alternatively, I've got another 12v port in the back of the car (for use by people in the back seats) - would that stay live?

thanks

drew

Marktheshark

Think its the one in the glove box, only one has a slot half as long again as the others, you see it has 3 terminals so you can move the fuse.

Strider590

It doesn't state the power output of that panel, I doubt it would supply enough current to keep a float charge on all but the sunniest of days.

You really shouldn't keep those connected without a charge controller, I used one on a small 12v SLA (for an electric fence) and on a very sunny day it was holding the voltage at 18v, this would almost certainly damage your cars ECU and cause the battery to "gas", effectively reducing it's life.

A car is designed to handle less than 16v, which is why smart chargers output 13.6v (float charge) 14.4v (bulk charge), 14.7v (AGM bulk) or 15.8v (reconditioning charge).

As a temporary thing, they don't supply enough current to maintain a healthy float charge. In the long term they need a charge controller to prevent damage to your vehicle.

womble12345

Dont do anything, if the car doesnt start when you are better just call your breakdown company for a jump start and then go for a drive to charge the battery back up. This assumes you have 'at home' cover on your breakdown cover.

ajb69

Thanks all. Breakdown cover may be the way to go.

Stupid question time - well, another stupid question time! - if I go and start the car up and run it at idle for a while, will that help or hinder? My gut feel is that I'll lose more battery starting up than I'll ever get back.

Marktheshark

I have a small Solar charger, never had any issues, Just leave it on the dash when the car is parked up for any period and it fires up first time.

Strider590

ajb69 wrote: »

Thanks all. Breakdown cover may be the way to go.

Stupid question time - well, another stupid question time! - if I go and start the car up and run it at idle for a while, will that help or hinder? My gut feel is that I'll lose more battery starting up than I'll ever get back.

What I would personally do, is find your radio code, once you have this just disconnect the battery.
A charged, relatively new car battery, disconnected from any load, should hold 70% of it's charge for 6 months. Typical self discharge is 5% per month.
In an ideal world you'd then put a charger on it once a week for 6 hours or so.

arcon5

Frankly if its off the road for a quarter of the year i'd forget the battery and give it a charge or put a new one on when the time comes. You may find there to be other problems anyway, sticking brakes one of the possibilities.

Ectophile

womble12345 wrote: »

Dont do anything, if the car doesnt start when you are better just call your breakdown company for a jump start and then go for a drive to charge the battery back up. This assumes you have 'at home' cover on your breakdown cover.

If the battery has gone flat, and been left flat for any length of time, then it will be beyond a quick charge up. You would be looking at charging it enough to get the car going so you can get down the motor factor's to buy a new battery.