Lead acid battery charger (or alternator) switching to trickle with (2025 Update)

The regulator doesn't care. It's the voltage that matters. Whatever

Actually less unless you want to pay for new technology like EFB or AGM.

What do you think is happening when you have a fully charged battery but have the AC on, the headlights on, the driving lights on, the seat warmer on, etc, etc. The *internal resistance* of the battery will be high when it is fully charged so most current will flow to the *other loads*.

Depends on the car. Some cars have a lot of parasitic loading, some have minimal parasitic loading, very few current cars have no parasitic loading.

Batteries lose charge even if nothing is connected to them. It's called

More education here;

It isn't concerned about *individual* loads. It looks at the *system voltage* and operates from that.

The starter wire, that big fat one, is *irrelevant* unless starting. The power to the vehicles *system*, usually fused, is but an extension of the B+ wire from the alternator. Once the alternator is running and producing charge, it takes over all electrical supply to the vehicle's various circuits. Technically, the battery no longer needs to be there, since all supply is provided by the alternator, but it does serve as a suppressor of spikes, prevents overvoltage, etc.

And that is what you would *expect to see* since you have just made a

Electrical systems - yes, alternators - no. The only part that has significantly changed has been the regulator and that function, in some case, is being done by the computer. The alternator regulator has been through a number of changes since its inception. The first were

Irrelevant to what I said.

Yep.

Very different to an alternator.

So very different to an alternator.

Still very different to an alternator.

So very different to a generator.

So very different to a generator.

But the other stuff is different, most obviously with the current batterys which cant even have more water added.

What sort of stupid wog are you ?

Irrelevant to your stupid claim about parallel circuits.

He's not talking about the voltage with the starter running.

Even sillier than you usually manage with computer controlled systems.

They werent used for that 100 years.

Wrong, as always, most obviously with the changer from generators to alternators.

Well, wherever you are, cars must be put together differently. I've worked on American cars, BMW, Mercedes, none had anything more than one cable to the positive battery terminal. Additionally, there are aftermarket battery cables for generic replacement, I've never seen one of those with more than one cable either. Just because you only have one cable, doesn't mean that the starter, etc can't be connected, it's just wire. There are many ways it can be connected and routed, there is no reason more than one cable needs to go to the battery.

Pity about that.

And so far I haven't seen any evidence presented here that shows modern ones can tell the difference and care about it either. The ones I've seen, still have a voltage regulator in the alternator that functions like it has for most of the last century. Rod claims to know so much, including that they use the resistance of the battery cable to measure current, but he can't produce anything other than his own flapping BS gums and he's likely just doing the usual, making it up on the fly and lying.

Go find a description of the voltage regulator/alternator and/or a schematic for that car. Give us the references. If something is telling the VR/alternator what voltage to target, then there must be an additional wire or connection of some kind. I have not seen that. The other possibilities are that the VR itself lowers the target voltage, based on? Makes no sense and I've never seen it mentioned anywhere. I just googled for VR and looked at half a dozen references, all just say the VR targets a specific voltage period. The other possibility is that when you read the voltage later, some other load is present that is lowering the system voltage that you see.

Rod claims that they have an extra sensing wire at the battery terminal and use the voltage there versus the voltage at the other end of the cable, to determine the current. I seriously doubt that, for obvious reasons involving the very large gauge cable and current of interest. And he can't produce a damn thing from anywhere that says that's what they do, except his own worthless statements. If it's done that way anywhere, it's not done on the cars I've seen here, that have just one battery cable on the positive terminal. Why doesn't someone show us an example, a description of one of these alleged fancy voltage regulators that are computer controlled?

What other way would you suggest to document that Rod is full of s*it most of the time?

One problem with what he's suggesting is the connection from the cable to the battery itself if I understand what he's saying. I've seen so many bad connections over the years. Wiggling that connection or putting a sheet metal screw in it changes the resistance dramatically. A few feet of wire in an engine compartment won't have much resistance to measure. It would take a very sensitive tester to measure that little bit. 14 awg copper wire has about 2.5 ohms resistance per 1000 feet. #2 awg wire has about 0.16 ohms per 1000 feet.

No it doesn't what? Of course the voltage regulator SENSES VOLTAGE because otherwise it obviously can't regulate it. It doesn't target CURRENT. And this is why you keep asking about how the VR knows how much current is going to the battery vs how much is going to the car. It doesn't. It doesn't care. It targets VOLTAGE and that's why it's called a VOLTAGE REGULATOR, not a current regulator. Good grief, this is explained all over the internet, not hard to find.

No, arguing with the Aussie troll who has a track record of BS and lies is the illness. Maybe you don't care about anyone's credibility and will debate nuclear physics with the village idiot who lies about most things. Do so at your own risk.

The voltage regulator actually doesn't need to actually know the current period. It just senses the system voltage and adjusts the current to the alternator rotor to maintain the target voltage of ~14V.

That's what I said - the aggregate current draw will be indicated by the voltage.

;-)

The issue is not how it can be measured, the question is if any cars actually do it, ie measure the current flowing into the battery and use it to control the alternator. I've never seen it, never heard of it. So far, all we have is Rod's flapping gums and he's made all kinds of false claims and lies here. And he said they don't use a resistor, that they just use the resistance of the battery cable. That doesn't make sense to us, for obvious reasons. So, we're still waiting for Rod to show us some documentation of what he claims cars do......

Must be why so many cars have more than one.

In fact f*ck all cars and trucks had an alternator before the 60s so you are just plain wrong, as always.

Nope.

What is measured is the voltage drop across that cable. That’s what gives you the current thru it, stupid.

Trivially easy to do by measuring the voltage drop across that cable.

That doesn’t happen with the car running.

Trivially easy to measure and the arent that small with the total current the entire electrical system takes and with the current that’s charging the battery.

Nothing to do with wasted energy.