Solar car battery chargers, do they work?

[~SlideWays~]

Had an annoying time last night with a flat battery in my Safari which is extra annoying since it is 24v so I can't just jump start it.

I'm pretty sure its just a case of slow drain from a 24v-12v inverter which does need to be on all of the time but it takes weeks for it to be a problem.

I'm wondering it a Solar charger is a good solution to keep it alive while being parked for weeks on end.

Has any one used one, do they work?
What sort of money do I need to spend for one that outputs enough power for a car battery (well two of them)?

[Lloyd]

They're about $50 for a 100mA job from Repco/Appco. I've got one sitting on the dash in my van, but I don't leave it long enough for it to ever go flat enough anyway. You'd be hard pressed to find a larger current one for a reasonable price.

[Mr Ree]

I have one plugged into my Supra as the battery has already dies 1000 deaths, its parked up nearly all the time, and gets driven very seldom.

I think its a 1.5W jobby, and its not really in an ideal position to get direct sunlight, more like light, with a bit of sunlight for an hour or two in the afternoon, and I would say it does next to nothing in its current configuration, even though it says it doesnt need direct sunlight to work.

Im going to extend the wires and mount it on the outside of the garage roof to increase its direct sunlight exposure, and just carefully silicone seal around the edge of the panel and plug to avoid water entering it.

I will do a comparison with a multimeter to see what difference it makes to charging when in/out of direct sunlight.

[evil_si]

Ive got no idea on the solar chargers but.

You can jump it,
Just connect 12v to 1 battery, if your not sure check it with a multi meter first,
each battery over its own terminals is 12v
Its not untill you connect 2 batteries in series that it becomes 24

[wde_bdy]

As evil_si said, can still jump it. Done it heaps on my Dyna van (before I replaced both batteries), jump pack on one battery and if that wasn't enough then jumper leads to the second off another car.

Callum

[matt dunn]

They're about $50 for a 100mA job from Repco/Appco. I've got one sitting on the dash in my van, but I don't leave it long enough for it to ever go flat enough anyway. You'd be hard pressed to find a larger current one for a reasonable price.

100ma is a waste of time as the average standby draw of a car is around double that.

Pretty sure I can do a 20W panel which is 1.6a or 1600ma for around $100.

Also had 10w ones but not sure on the price from memory.

[Lloyd]

Sorry, yeah you're right Matt. The original reason for getting mine was for the bike now that I think about it.

[Stu-]

Ive got a 10w one - tiz awesome

[~SlideWays~]

As evil_si said, can still jump it. Done it heaps on my Dyna van (before I replaced both batteries), jump pack on one battery and if that wasn't enough then jumper leads to the second off another car.

Callum

Cheers guys, I know you should be able to but it hasn't worked so far since both batteries are low. I had tried to jump it off my Chaser which has a nice big CCA battery but all it did was increase the frustrating starter solenoid click. I left it running for 10min but it still wasn't enough so I gave up because I was already 30min late.

matt dunn, would your 20w option work with two batteries/24v? Are they the terminal connection type or plugged into the cigarette lighter?

[matt dunn]

would your 20w option work with two batteries/24v? Are they the terminal connection type or plugged into the cigarette lighter?

No 12V only, probably need one wired to each battery,
and they are are terminal type not cigarette lighter plug type.

[Santa'sBoostinSleigh]

you could get a couple of small panels and regulators, or go for a fancy option and get a 24v panel and reg, then mount on something.
solar is cheap nowdays, especially when you get wholesale prices through work

[XSVWGN]

I have a solar panel for the corolla and it cost me $35.90 from Jaycar. Works really well!