changing a car battery - gadget

[bigdee]

Re: changing a car battery - gadget

Putting a battery charger on it could kill the ECM depending on what the open circuit voltage is of the battery charger is. Not all battery chargers are the same.

Another valid point. Battery chargers (cheap ones) use simple AC rectification with no or little filtering which induces a very choppy DC voltage.

 

[MTboatguy]

Re: changing a car battery - gadget

All of my chargers are Schumachers and I have never had a problem with them, they are all regulated and taper as the batts get charged.

 

[bruceb58]

Re: changing a car battery - gadget

All of my chargers are Schumachers and I have never had a problem with them, they are all regulated and taper as the batts get charged.

Have you ever measured the open circuit voltage? We aren't talking a battery load on the charger here. We are talking an ECM that only puts on a very small mA load. My point is that not all chargers are the same and some shouldn't be used.

Of course, why one would go through the trouble of even putting a battery charger on while disconnecting the battery kind of baffles me anyway. Add to the fact that if you accidentally have the charger connected to the ECM with reverse polarity, you have just fried the ECM.

 

[bigdee]

Re: changing a car battery - gadget

All of my chargers are Schumachers and I have never had a problem with them, they are all regulated and taper as the batts get charged.

They are intended to charge a battery and not be used as a power supply. When used as a charger the battery buffers the dirty voltage produced by the charger. Some of the more pricey chargers have a transformerless switching power supply which may produce cleaner power but I don't know that for sure. The open voltage level would still be a concern. Bottom line is a charger is not to be used for this application....a 9 volt battery would be a safe alternative.

 

[bigdee]

Re: changing a car battery - gadget

Just for laughs & giggles I checked the output of my 10 amp battery charger. 14.43 volts BUT here is the kicker...it was PULSATING DC at the rate 0f 119 hertz/second. That is NOT what you want powering sensitive electronics!!

 

[bruceb58]

Re: changing a car battery - gadget

Just for laughs & giggles I checked the output of my 10 amp battery charger. 14.43 volts BUT here is the kicker...it was PULSATING DC at the rate 0f 119 hertz/second. That is NOT what you want powering sensitive electronics!!

You need to measure AC as well and add half of that to your 14.3V

 

[bigdee]

Re: changing a car battery - gadget

You need to measure AC as well and add half of that to your 14.3V

Yes that is correct but I did not want to confuse someone checking behind me measuring DC volts. The delta was 16.5. You just re-enforced my point on this being a simple and unfiltered (choppy) voltage source.

 

[coolbri70]

Re: changing a car battery - gadget

I have one in my tool box I work at a dealership, I only bother with it if a customer asks if I can save radio presets, or if there is an aftermarket stereo that I don't know how to set the clock. it works:noidea:

 

[MTboatguy]

Re: changing a car battery - gadget

Who ever thought that a simple question about a $6 gadget would evolve into such a deep conversation!

Geeze!



Must be winter time!

:lol:

 

[bruceb58]

Re: changing a car battery - gadget

Who ever thought that a simple question about a $6 gadget would evolve into such a deep conversation!

Geeze!

It's an interesting discussion. I don't see the problem!

 

[lakelover]

Re: changing a car battery - gadget

^^^ Yeah, gather 'round the pot belly stove and stick your arm in the pickle barrel!