Charger and Battery

If there was any current drawn from the battery, its output voltage would immediately drop (even if only a tiny bit), so it would start drawing current from the (now higher voltage) charger. So it's balanced (i.e. floating).

If the load was drawing enough current to make the charger output fall, the battery would then start to provide current, but only until its voltage matched the charger output voltage.

The battery is a voltage source in series with an internal resistance. The charger voltage is higher than the battery voltage so when the charger is connected to the battery, current flows into the battery. Current flows from a higher voltage to a lower voltage.

You might as well say why are you not drawing from the wire as well...

Well,,,,,,,you are.

That's why you should always use the shortest wire runs possible.

It takes less electricity to fill a short wire than a long one.

Off topic????

How about this unretouched photo of a technician pre-filling wires with electricity from his metal electricity holding tank.

Typical Lyn. Mean, bad, and nasty. Clearly the OP doesn't know anything about electron flow, or the physics of it, so, equally clearly, he doesn't know enough to realize you are "pulling his leg". Naughty man!

But, funny, too!

How much weight would you say those bamboo rungs hold....?

At least as much as he weighs, anyway. I know when I was stationed in Guam, and then in Japan, we used to watch in awe as they scampered up and down scaffolds made of lashed bamboo, such that they ran along single bamboo poles, using their toes to grip, inside those split-toe work shoes they wear. I wondered how the bamboo could be strong enough, and how they could NOT miss and slip off as they ran around on them.

But I guess it works. This picture sure makes it seem so, no?

My calculations show they are capable of supporting 205 pounds and 3600 ohms.

A great ladder for the Ohmless....

LOL!!!!

I am answering as though you are talking about LA (lead acid) batteries and LA Battery Charger. Other chemistries react differently in some respects.....

Here is a simplified version of what happens, hopefully you can follow the logic!!

You are right that they are two different voltage sources, that is until you connect them.

Then, the charger will normally (assuming its switched on!) have the higher voltage, and the battery sort of looks more like a variable value resistor at the point of switch on. Its resistance presented to the voltage of the battery charger will allow a certain current to flow, charging the battery.

As the battery charges, its resistance increases (actually its voltage increases, lowering the difference in voltage), thereby reducing the charging current. Same but different!!

At some point, the battery is at the same voltage level as the charger, so no more current flows.

If a battery is fully discharged (forgetting for a moment the damage this causes to some types of LA battery),then its resistance will be low and the charger will deliver a very high current.

Some chargers may even turn off themselves, as a way of preventing damage to the charger by this high current.

This can sometimes be averted by placing a high wattage low Ohm resistor in series with the charger, fooling it into thinking that the battery is not quite so "empty"......

But it must be removed once a reasonable charge has been transferred into the battery, so that the charger can complete the charging fully in a reasonable time. For example, a 1 amp charger, then a 12 Ohm resistor will make sure that the charger is not unduly overloaded.

That is a "quick & dirty" fix that will work on all but the most intelligent chargers....but the really intelligent ones, seeing the high current flow, simply cut down the voltage until a reasonable charge has been built up....

Leaving the resistor in will just slow down the charging rate dramatically, it will not prevent a full charge being achieved.

Overcharging is bad for the battery and should be avoided at all costs, or an early life failure of the battery is already programmed....many cheap chargers have little or no charge control and will damage a battery if simply left connected....

I hope this goes part way towards a better understanding of LA Batteries.....