unusual way to charge a car battery

[Thunderchild]

ok you will say I am nuts but strraight from the mains thru a rectifier 220V DC to battery with a normal liightbult in series. ok i know this is a very wasteful method in veiw of charging a battery but say I needed a light too ? I would get about the same light and the bonus of a charged battery with the downside thhat it would be dangerous to touch the battery terminal as oposed to a normal charger. this may work great a trikle charger say a low power bulb used now and then. OK i'm nuts but i won't blow a thing up would i ?

 

[ThermalRunaway]

Hmmmm, I wouldn't count on that!!!

Personally I'd avoid that idea like the plauge. Can you imagine accidentally sending 240V DC through your vehicle electrical system? Bye bye ECU, bye bye complex cruise control electronics, and electric windows, and alarm immobiliser system, and engine managements control electronics.

Bye bye a huge wadd of cash!!!

Brian

 

[ThermalRunaway]

Oh and another thing, what about when you initially switch the thing on? Who's to say that all of the H.V. would immediately appear across the bulb? For fractions of a second, perhaps H.V would appear at your vehicle's fuse box. So even if you are EXTREMELY careful, I would STILL avoid that idea like the plague!

Brian

 

[JimB]

A rather rough and ready technique, but if the battery was not on the car, and you did not touch the battery while the mains was switched on, yes it should work OK.

JimB

 

[k7elp60]

I agree the battery should be out of the vehicle. I am not sure but it is possible that some damage could occur to the battery when the power is first
turn on. The typical cold resistance of the lamp filament is about 1/10 the the hot resistance. That is why incandescent lamps fail whenfirst turned on.
So for an instant the current into the battery would be high and the voltage my be high.
Although I have seen many older circuits that use a lamp in series with a power supply to charge batteries. The lamp seems to limit the charge current
to a safe value. All those that I have seen were low voltage supplies and not a mains operated circuit.

 

[Thunderchild]

hm well even in the case of a 100 W bulb we are talking like 0.5 A so even if 10 times the current was to go thru that is the regular 5 A, of course the battery will be off the car

 

[Oznog]

The worst part is there's nothing to make the current stop, or even slow down, when the battery is fully charged. This overcharge will kill the battery quickly.

 

[Russlk]

I used that system for years with no problems. If you leave the battery on the charger for months with a 100 watt lamp, it will evaporate the water, so keep an eye on it. And, protect it from curious children!

 

[mramos1]

Seems like everyone is doing it. And this guy is gonna patent it.

https://www.miami.com/mld/miamihera...e/cities_neighborhoods/pinecrest/14731378.htm

Russlk, I would be after this guy man..

I just do not see me charging my cellphone with a bunch of lights on in the room as I sleep and the chance I might wake up and touch it.

Comment:

So we are talking 110VAC or 220VAC though a 100 watt light bulb to a DC battery of any kind (1.5VDC 140ma to 12VDC 55AMP)????? Please let me know. And what about deep cycle, li-po, etc.. Or is this just lead acid. No diode and no polarity?

(mramos is looking for a long extention cord and old battery... The little silver one explode and can be fun; while calling the kids out to the yard.)

 

[stevez]

When a light bulb fails it does not always go to an open circuit right away. Every now and then when a light fails at home, I notice quite a flash followed by the opening of the circuit breaker. I have to presume that a significant amount of current was flowing, if only for a moment.

 

[Nigel Goodwin]

When a light bulb fails it does not always go to an open circuit right away. Every now and then when a light fails at home, I notice quite a flash followed by the opening of the circuit breaker. I have to presume that a significant amount of current was flowing, if only for a moment.

It's VERY common for a light bulb to go S/C as it fails, this is why the triac's in light units often fail when a bulb goes - and why the MCB trips when a bulb fails!.

 

[stevez]

Possible failure is one very good reason not to use a capacitor followed by a rectifier to do the same thing.

 

[Thunderchild]

hm well that thing that is getting a patent is a bit nuts to me as he is using it primarily to charge and using like 2000 % the current he needs to, my idea was use the light with the side angle of a charged battery as well this guys sounds a bit nuts unless it is some universal switching supply.

 

[mramos1]

I still have to ask. I never thought about AC from the (US 110VAC) house through a light bulb to my car battery to charge it. And I have done a lot of weird stuff in the garage.

What voltage and current range battery work with this? Just AC to the battery thru an light bulb.. The light bulb must be key.

 

[Nigel Goodwin]

I still have to ask. I never thought about AC from the (US 110VAC) house through a light bulb to my car battery to charge it. And I have done a lot of weird stuff in the garage.

What voltage and current range battery work with this? Just AC to the battery thru an light bulb.. The light bulb must be key.

You've NOT read the thread, it's mains through a RECTIFER!, then a bulb to the battery! - so it's DC.

 

[Thunderchild]

precisley just like a normal charger but without a transformer

 

[ZIGGY_DAN]

I believe the voltage in italy is 230VAC, anyway thats RMS, when rectified it will be

230 x 1.414=325.22V

and accounting voltage drops of diodes

325.22-1.4=323.82V

i'm not so sure a bulb rated for 240VAC could take about 330VDC, a higher voltage through same resistance = higher current, wouldn't a higher current destroy the filament??

i suppose you could run two bulbs in series.

still sounds dangerous.

 

[ThermalRunaway]

I certainly don't think I'd be hooking my car up to one, I wouldn't want to take the risk of 240V D.C. appearing across the rather complex ECU under the bonnet. And, if you're going to remove the battery then it pretty much defeats any convenience the solution would have offered. I think I'll stick to my usual charger. Let us know how you get on though!

Brian

 

[JimB]

I believe the voltage in italy is 230VAC, anyway thats RMS, when rectified it will be

230 x 1.414=325.22V

and accounting voltage drops of diodes

325.22-1.4=323.82V

i'm not so sure a bulb rated for 240VAC could take about 330VDC, a higher voltage through same resistance = higher current, wouldn't a higher current destroy the filament??

i suppose you could run two bulbs in series.

still sounds dangerous.

Ziggy, you are confusing yourself.
The DC value of 1.414 x RMS is only applicable when there is a filter capacitor after the rectifier. Without the the filter cap the average (?) DC voltage will still be 230volts.

JimB

 

[mramos1]

My mistake.

I missed the rectifier part. I thought that was odd.

I missed it like other missed me asking the question prior, about no diode and no polarity. So I guess it happens.