Charging car battery

Trying to start my car with sparkrite charger , power light is on but no lights coming up on charger lights. How long does it take for even 25% battery to appear or am I doing something wrong. Pls help as need to move car asap.

Reply to
Kc
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I don't know what a 'sparkrite' charger is, but if it's something fairly modern and the battery has been flat for some time, it may refuse to start charging at all.

Chris

Reply to
Chris Whelan

Nor do I. Agree it could be one of the modern ones which won't work with battery below about 9V. Or maybe the clips are not on properly. Sparkrite manuals readily available via Google.

Reply to
newshound

Connect a DVM set to volts across the battery. That will show if it's charging or not.

But I'd say all battery chargers made in the last 20 years or more won't start charging a totally flat battery.

One way to get them started is to jump another good battery to the flat one with the charger connected too. That should kick the charger on. You may have to leave it like that for a while, though.

Reply to
Dave Plowman (News)

But I'd guess the OP doesn't even know what a DVM is

Not quite true, I have one of the Machine Mart jobs which can supply a cranking current for a few seconds, but it feels like it has the traditional transformer build and certainly has no such limitations when used in straight charging mode.

Agreed.

I keep saying this, but I am a big fan of the £40-odd lithium ion "bricks". Even if you only use it once a year, it is worth it for saving the faff of connecting up a charger, jump leads, or tow rope depending on circumstances. I keep one in two of my four vehicles. (They also get used from time to time as torches, phone or satnav chargers, or to power a 12 volt tyre pump).

Reply to
newshound

So he can Google can't he?

Or more to the point doesn't know he's wandered into the USENET.

I just get my c1980 4 amp 6/12V Halfords battery charger out.

Reply to
Peter Hill

How does it provide reverse polarity protection?

Reply to
Dave Plowman (News)

Yes - a nice basic old unit with only fuse protection will often kick out a high voltage with no load and have some chance of getting a totally flat battery to accept a charge.

Reply to
Dave Plowman (News)

No idea. But then my chainsaw doesn't have a guard to prevent me trying to cut my hand off.

Reply to
newshound

The reverse polarity protection is not for safety as such, but to prevent the charger being damaged by doing so.

The usual method is a relay with a diode in series with the coil, getting its volts from the battery. Will normally make with only a few volts. Battery totally flat, no connection.

Reply to
Dave Plowman (News)

The point I was trying to make, perhaps badly, is that if you at least sort of understand what you are doing, you don't connect a red charger lead to a negative battery terminal without expecting something to blow.

I imagine, but don't know as I have never tested it, is that in the "cranking" chargers there is either a thermal fuse or a trip/cut-out on or near the transformer which kicks in if the user tries to run the starter for ten seconds or more. I guess that this might also provide protection against reverse polarity even if there isn't a diode (but there probably is).

Reply to
newshound

You'd hope so - but many European cars use brown as the ground lead - and as regards mains UK wiring, brown would relate to red. And the + &- markings on a battery may not be that obvious to the casual user.

Reply to
Dave Plowman (News)

Not to mention the large number of people, particularly men, that are colour blind.

Reply to
MrCheerful

Or the huge number of idiots in the world!

Reply to
Scott M

But I am sure that, like me, you are not casual about polarity!

Reply to
newshound

But you have to be careful not to reverse the polarity of the neutron flow. Unless you have the time and space to do so, of course.

Reply to
Ramsman

True. It's all too easy for us lot to say it's very easy to connect a charger correctly. But there are lots out there who can't. So a sensible maker provides protection to a charger. And not a fuse which would need replacing if blown.

The old saying is you need to make something foolproof. And idiot proof. And if possible c**t proof.

Reply to
Dave Plowman (News)

I got the reference! :-)

Reply to
Scott M

Nonsense, just wrap some silver foil around it.

Reply to
Gerry H

I read the other day of a redneck who was driving his truck when there was a small explosion below the dash. An unused bullet had been used as a fuse.

Reply to
MrCheerful

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