Solar trickle chargers, any good?

Atlantic Dawn

Anyone used a solar trickle charger before and can you recommend them? You basically plug them in to the cigarette lighter socket and it charges the battery gradually using sunlight. I've a relative who uses a car seasonally and it's a pain having to keep charging the battery every time he leaves it layed up. Here's one on Ebay as an example...

http://www.ebay.ie/itm/12v-Car-Solar-Sun-Light-Powered-Trickle-Battery-Panel-Charger-Boats-Home-Use-UPS-/221004104229?pt=UK_Gadgets&hash=item3374df0225

Voodoomelon

By my calculations, that solar panel would charge a 100Ah battery in 41.5 days, assuming maximum light and hence the maximum 100mAh output.

Gives a new meaning to the work trickle.

keithclancy

My Solar Charger with three panels after about 8 hours of direct sunlight at 30 degrees it had enough to half charge my phone (using the builtin battery pack)

I seriously doubt it would make any impact on your car battery.

Senna

They dont charge a flat battery, they just add enough power over time to a good battery to keep the charge up, hence trickle. In my experience they work very very well.

Atlantic Dawn

But say from start if battery is fully charged would this trickle charge maintain the full charge in the battery?

Senna

Atlantic Dawn wrote: »

But say from start if battery is fully charged would this trickle charge maintain the full charge in the battery?

Yes, for months and months.

keithclancy

Senna wrote: »

They dont charge a flat battery, they just add enough power over time to a good battery to keep the charge up, hence trickle. In my experience they work very very well.

Or you could just get a new battery, I left my car layed up for 6 months, came back and it started no problem.

crosstownk

It might be useful to keep an idle battery topped up - if you had a camper van or weekend car that sits on the driveway most of its life and is used infrequently. If you need something to charge a flat car battery in a hurry then this is not your man.

Senna

keithclancy wrote: »

Or you could just get a new battery, I left my car layed up for 6 months, came back and it started no problem.

New battery wont be much use if, like me, car could be sitting up for months on end a couple of times a year. Even a new battery wont last 6 months in most cars, not a chance in mine anyway, the alarm system does go into power save mode but will drain a new battery in a month.
The battery only needs to lose a small amount of power and it wont be enough to start it.

keithclancy

Senna wrote: »

New battery wont be much use if, like me, car could be sitting up for months on end a couple of times a year. Even a new battery wont last 6 months in most cars, not a chance in mine anyway, the alarm system does go into power save mode but will drain a new battery in a month.
The battery only needs to lose a small amount of power and it wont be enough to start it.

Why not just disconnect the battery ?

beprint

I use one on my boat and it kept the battery charged all winter! It was only 13 quid in maplin!

Senna

keithclancy wrote: »

Why not just disconnect the battery ?

Jesus, you'd think spending €20 so i could jump into the car and drive it when ever i want wouldn't need so much explanation:D.

Yes i could disconnect the battery, yes i could go out and start the car once a week also. I could also not have two cars (sometimes more) which would means it was drove every day, but alas i choose this life and its a cross i must bare.

keithclancy

Senna wrote: »

Jesus, you'd think spending €20 so i could jump into the car and drive it when ever i want wouldn't need so much explanation:D.

Yes i could disconnect the battery, yes i could go out and start the car once a week also. I could also not have two cars (sometimes more) which would means it was drove every day, but alas i choose this life and its a cross i must bare.

Fair enuff ..

When I brought my car over here it was a bit like a chocolate fireguard, 15 minute walk was upto a 40 minute drive

SRBRGS

In most cars there's only power going to the cigarette lighter when the ignition is switched on or in the accessory position.

I've wondered before how do you get around this with these solar chargers? (without rewiring)

Senna

SRBRGS wrote: »

In most cars there's only power going to the cigarette lighter when the ignition is switched on or in the accessory position.

I've wondered before how do you get around this with these solar chargers? (without rewiring)

They all come with clamps just to hook directly to the battery.

crosstownk

SRBRGS wrote: »

In most cars there's only power going to the cigarette lighter when the ignition is switched on or in the accessory position.

I've wondered before how do you get around this with these solar chargers? (without rewiring)

Good point.

unkel

Voodoomelon wrote: »

By my calculations, that solar panel would charge a 100Ah battery in 41.5 days, assuming maximum light and hence the maximum 100mAh output.

Gives a new meaning to the work trickle.

Show us your calculations!

I have one like that, and indeed you'll never get anywhere near the max output on it. On the hottest (cloudless) day of summer at 1PM at a perfect angle in this country you'd get about half. On a cloudy day it's near zero. I guess when you park up the car with a fully charged battery, it would do the trick(le) no problem though...

That said, I have another one 4 times the rating (which works better too) on my shed roof which keeps a booster pack charged winter and summer. I regularly use the compressor in this booster pack regularly to pump up things too

Senna wrote: »

They all come with clamps just to hook directly to the battery.

Grand if your battery is in the back, not so good if it is under the bonnet where the engine is. Problem with wiring then too.

Voodoomelon

unkel wrote: »

Show us your calculations!

I always use this airsoft battery and charger calculator, same principal to all batts/chargers applies: http://www.arniesairsoft.co.uk/?filnavn=/downloads/downloads.php

(down the bottom)

Stinicker

All you scamps with your solar chargers, back in my day we parked things on a hill and hill started it in high gear!

Interesting product though, could find some interesting non-motoring applications for it also.

unkel

Voodoomelon wrote: »

I always use this airsoft battery and charger calculator, same principal to all batts/chargers applies: http://www.arniesairsoft.co.uk/?filnavn=/downloads/downloads.php

(down the bottom)

Or how about 100Ah / 100mA = 1000 hours = 42 days

That is of course in the Sahara, provided the sun is shining at its most powerful 24 hours a day

Stinicker

unkel wrote: »

Or how about 100Ah / 100mA = 1000 hours = 42 days

That is of course in the Sahara, provided the sun is shining at its most powerful 24 hours a day

Your thinking Greenland and the land of the midnight sun Unkel!

unkel

You missed my smiley?

In Greenland it would take about 42 years to charge that battery

Sesshoumaru

You could connect one of these

http://www.optimate.co.uk/optimate%205.htm

You can connect it with some standard clips or you can leave your battery wired up so you can plug it in with one clip.

machineman

I fitted one to my sisters daihatsu charade , it was constantly flat due mainly to not been driven enough . It didnt really make any difference and I had it wired direct to the battery.