battery charger

[kurt v]

If a battery charger is unplugged and the cables are left on the battery will it draw down the battery ?

thanks kurt

[ford38v8]

I’ve also thought about that possibility, and have decided that not only do I not have a clue, but I’ve seen electricity do some strange things, so I unplug and disconnect everything!

[radiation]

Some will and some won't, the ones on my SUV and pickup draw the battery down but the one on my wife's car doesn't!

[Drbrown]

Perhaps testing the battery side of the circuit with a meter might show. I have left my battery maintianer/minder unplugged and but attached to my pattery without problem.

[DaleandNatalie]

I’ve never seen a normal battery charger that would drain the battery if left connected and unplugged, but I don’t use maintainers so I can’t say about them

[ScubaChief60]

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I have a solar maintainer on my 6-Volt... and installed a diode on the positive feed from the solar panel to prevent any back-flow of current. Placement of the diode in my setup is within 6 feet of my battery. Not sure it;s entirely necessary but seemed like a good idea. Thoughts appreciated.

[itslow]

It will depend upon the charger. Which brand and model do you have? An email to its customer support may be able to provide you an answer.

[rotorwrench]

I still use antique chargers. They have a power diode or a bridge to prevent back flow but I always disconnect the charger when I'm not charging a battery. This is how I can still run my antique chargers. They'll last forever if you take care of them.

[hueyhoolihan]

i often wonder if there's a color (only two colors would be necessary) coded diagram somewhere on the net of everything that is actually attached permanently to the positive terminal and negative terminals of the battery. it would give a true impression of where current is available at all times even with the ignition turned off.

it would show the entire engine, transmission, frame, body panels and elements of the dashboard and a pole on the battery. and a much smaller part of the car, like the lights and gauges that run to ground, as part of the other pole.

it would then be much easier to visualze and answer these types of questions, i think.

anyway...

if a charger is disconnected from it's power source i can't imagine where battery current would would go.

[Mart]

I don't think an old fashioned charger would drain the battery but I have a "modern" one which puts a light on when you connect it to the battery. This is with the plug not plugged in. When I plug it in the power light comes on and the light that was on indicates it is charging.
So would a charger flatten the battery if connected but unplugged?
Old fashioned charger: not sure but suspect not.
My "modern" charger: I think it would.
You "modern" charger: Don't know.

Not much help am I.

Best bet is to disconnect.

Mart.

[tubman]

I have a series of different makes of battery chargers and maintainers on all my stuff over the winter when I am in Florida. I leave them permanently hooked up and all connected to a couple of mechanical timers, set to come on for 15 minutes twice a day. I have been away at least 6 months a year for the last twenty years, and have never had a problem.

[hueyhoolihan]

most small electronic devices (as small and simple as a toaster in many cases) today are complete computers and have small rechargeable batteries in them. it's required to complete a data saving orderly shutdown of the system in the event the plug is pulled from the wall. i imagine modern chargers are similarly equipped. they, like most solid state devices are very sensitive with regard to power fluctuations. i doubt whether designers would consider using the battery they were connected to for any type of power.

it's why such devices often don't show the common signs that we, of a certain age, expect to see when we turn or push the "OFF" buttons. small running lights, often green or red, stay on for a few seconds or even minutes in some cases.

[Mart]

What I do know is that my modern charger won't charge a dead flat battery. I have to rock out one of my old jobs and that will get it going.

[hueyhoolihan]

Originally Posted by Mart

What I do know is that my modern charger won't charge a dead flat battery. I have to rock out one of my old jobs and that will get it going.

now you've got me wondering if companies that manufacture battery chargers also make batteries.

i'm SUCH a skeptic...i know.

[rotorwrench]

Modern chargers use more solid state components to control the charge rate, output voltage, and back voltage when the charger is unplugged. They likely use a diode bridge that may or may not have the large power diode like the old ones have. The more electronics there are, the more vulnerable to failure the unit is. Most garage spaces or shop buildings are lucky if they have a heater let alone an air conditioning system. The lack of climate control also makes electronic equipment vulnerable if the humidity is too high. The older chargers generally have a multi-stage set up of power coils with a switch to control voltage output, an amp meter, and the power diode or diodes to act as a one way valve for current to prevent back flow if left connected with the wall plug pulled. They can take a pretty harsh environment.

Coloring the wiring for identification in motor vehicle design is the easiest way to ID the wires of the different circuits. Most automotive wiring is just for half of the system circuit and is generally just the power part of the equation. The ground plane made up of all the steel or aluminum structure of the car provides that unless the body is of a non conductive material like fiberglass. In that case, it would require ground wires to the frame structure to complete the circuit.

In aviation, 99% of wiring is specially coated wire of adequate gauge that is all white in color. The manufacturing regulations require the wire to have a code printed on at 6 to 8 inch intervals for identification. The number letter code tells what system it's for with an individual number and gauge code for each separate wire. The circuit diagrams show the code of each wire and the terminal blocks are all lettered or numbers for connections. This also applies to switches, components, and other connections of the circuits like plugs and individual single wire connectors. Everything is code numbered and located by diagrams. The only bad thing is that the codes are small and hard to see for old men like me plus they deteriorate over time that even makes it more fun to ID. The color codes don't seem too bad but the cloth covered wire types deteriorate as well and pretty quickly where the wires are exposed to the light of day.

[farmertom]

Originally Posted by Mart

What I do know is that my modern charger won't charge a dead flat battery. I have to rock out one of my old jobs and that will get it going.

I totally agree Mart,but on my '37 i had a problem with the gen. cutout it let the brand new 6volt battery go flat.hooked my fairly old maintainer (maybe 10 yrs old) the batt would not re spond with chargeing.kept throwing the red indicator light so i tried to fool it and kept un plugging the maintainer and connecting it. to fool maintainer like some one had said on the barn and it worked it brought batt back to full charge. then put the new gen. cutout on and all was good. as a side note these gen. coutouts are hard to find at most of the suppliers and even maybe still. mind you the ones i bought are listed are for 8n ford tractors by implement dealers are sold on amazon or walmart online. they are inexspensive and a crap shoot offshore product,but the only choice. after taking apart the original cutout and soldering one wire and adusting the points inside the cutout that worked for awhile then i tried the 8n cutouts which like i had said. thought this might help some of you guys. Tom.

[alchemy]

Originally Posted by ScubaChief60

I have a solar maintainer on my 6-Volt... and installed a diode on the positive feed from the solar panel to prevent any back-flow of current. Placement of the diode in my setup is within 6 feet of my battery. Not sure it;s entirely necessary but seemed like a good idea. Thoughts appreciated.

If you get back flow on a circuit hooked to solar, does it make the sun brighter?