How to know battery going to be flat?

[inlinesix]

So you mean the battery doesnt die, it just gets fried?

 

Wah lau, Mini design fault .

 

Battery will die after 2 years mainly from heat within engine bay

 

The battery will hold lesser & lesser charge to the extent that you will feel it.

 

[Kb27]

Lead-acid batteries like to be kept charged all the time.

It will last longer when kept at full charge at 12.6V.

 

However, heat kills battery.

 

When you're charging the battery with high current, the battery gets hot. More current, more heat.

Worst still, is it gets charged in a hot engine compartment.

That's why they don't last long.

 

The best place for the battery to live longer is like BMW style, battery in the back, away from heat.

[Throttle2]

Battery will die after 2 years mainly from heat within engine bay

 

The battery will hold lesser & lesser charge to the extent that you will feel it.

 

Yes, true. Up to a certain point, i can sense that the battery holds probably lesser charge but still very good. Maybe becos my cars and bikes are all pretty low mileage compared to the usual.

 

That would contribute to the reason why i dont need to change batt so often too.

[inlinesix]

Yes, true. Up to a certain point, i can sense that the battery holds probably lesser charge but still very good. Maybe becos my cars and bikes are all pretty low mileage compared to the usual.

 

That would contribute to the reason why i dont need to change batt so often too.

 

Maybe mine is slightly higher than yours like 13k km per annum.

[Kklee]

Have you tried or been to a battery workshop where after they jump start your car, they removed both of your battery terminals and yet the car is still running haha

 

Yeah,   seen that before - quite fascinating.  

[Gnahp]

wah, how can I missed this charger talk

 

[Throttle2]

Yeah, seen that before - quite fascinating.

If a mech ever leaves your car engine running without any connection to any battery, i would advise you never to go back to him.

 

Its a disaster waiting to happen.

 

Fascinating isnt quite the word.

Frantic Fear would be better.

[Throttle2]

wah, how can I missed this charger talk

 

 

Wah wah wah, charger kingpin lai liao

[Beregond]

Yeah,   seen that before - quite fascinating.  

actually quite normal.

most car the battery only use to start the car.

once running it rely on the alternator power to run the car ,

not the battery

 

thats y alot of time, when u got a flat battery , u ask some 1 to jump start for u ,

as long as u dun off the engine u can drive to workshop to replace.

 

its another way to test if your alternator working or not also,  

if the car is running and battery is remove and your engine stop.

high chance your alternator is not charging,

[Kklee]

If a mech ever leaves your car engine running without any connection to any battery, i would advise you never to go back to him.

 

Its a disaster waiting to happen.

 

Fascinating isnt quite the word.

Frantic Fear would be better.

 

Still looking for information on the after effects. 

Frantic fear would be seeing the alternator voltage fluctuating between 9v to 16v.  

[Kklee]

actually quite normal.

most car the battery only use to start the car.

once running it rely on the alternator power to run the car ,

not the battery

 

thats y alot of time, when u got a flat battery , u ask some 1 to jump start for u ,

as long as u dun off the engine u can drive to workshop to replace.

 

its another way to test if your alternator working or not also,  

if the car is running and battery is remove and your engine stop.

high chance your alternator is not charging,

 

Maybe that is the reason why sometimes they the battery a starter battery. 

Yeah, I was reading that is a way to test the alternator. 

 

Actually,  after knowing more about batteries, I am reluctant to help or get help to jump start.

On my previous car,  the battery charging voltage is 14.8V - worried that it may "kill" mine or the other party electronic system ! 

[Throttle2]

If you read most car owners manual, it will also tell you that disconnecting battery from car beyond certain period of time will cause your onboard computer systems to mess up.

 

I just surf and paste this for your info.

We all do what we prefer.

[Kklee]

If you read most car owners manual, it will also tell you that disconnecting battery from car beyond certain period of time will cause your onboard computer systems to mess up.

 

 

 

Eh...i thought we are discussing a started car cannot continue to run after battery is disconnected? 

 

Of course some cars cannot disconnect battery for certain period which may cause onboard computer systems to mess up.

Some folks seems to use this method to "reset" ECU.

[Kb27]

Still looking for information on the after effects. 

Frantic fear would be seeing the alternator voltage fluctuating between 9v to 16v.  

 

It's a bad practice to remove the battery after the car is running.

Alternator is full of coils and inductance.

The moment a battery is disconnected, when the alternator is running, a voiltage spike occurs.

It's a transient spike, like a lightning strike.

If the spike is high enough, it may damage expensive electronics in your car, like a ECU.

 

If nothing happens, everybody happy.

 

Battery soaks up any electrical transient spikes like a sponge.

 

It is only damaged by consistent high voltage from the alternator, 16V and above.

This is basically boiling the battery.

Regular lead-acid battery contains 1/3 sulphuric acid and 2/3 water.

The water will be boiled off, leaving the battery extremely hot, and prone to explode.

[Kb27]

Another bad thing to do is during jump starting.

Most website will teach you this way.

1. Connect up the cables

2. Helper car start engine, even revving engine

3. Then start the car with the bad battery.

 

This is so wrong.

 

What happens when the car with bad battery is fired up ?

It's alternator output clashed with that of the helper car alternator.

They are definitely of different voltage and that spike occurs.

 

When you connect cables to good batteries, you may see spark. That's bcuz of the difference in voltage or potential difference.

Large current flows and melts metal. That's how they do arc welding.

You don't really want to do arc welding when you're connecting batteries.

 

For the correct and safe way to jump start another car, just connect up the cables, but do not switch on the helper car engine. Don't even insert the key in, less the key sense, turn on some electrical circuits in the helper car.

 

What you're using is the helper car battery only.

If the jump start fails, the possibility is the helper car battery is weak OR most likely the (cheapo) jumper cable wire is simply too thin.

 

Earlier on, I had someone ask me to change battery. When I reached his location, I checked the battery was still good, but he couldn't start the car. Then he told me he had helped jump start a diesel van, with his engine running. After that van started up. He shut down his car engine and couldn't start anymore.

Edited July 24, 2017 by Kb27

[Throttle2]

Eh...i thought we are discussing a started car cannot continue to run after battery is disconnected?

 

Of course some cars cannot disconnect battery for certain period which may cause onboard computer systems to mess up.

Some folks seems to use this method to "reset" ECU.

Yes and more than that.

I will never let my car engine run without a battery

Dont even say to drive

Would you?

 

A started car will die when the battery is fully disconnected.

Even if it doesnt dir instantly, it will after a while.

 

Maybe bikes and cars are different.

But my bike was like that.

[Kklee]

It's a bad practice to remove the battery after the car is running.

Alternator is full of coils and inductance.

The moment a battery is disconnected, when the alternator is running, a voiltage spike occurs.

It's a transient spike, like a lightning strike.

If the spike is high enough, it may damage expensive electronics in your car, like a ECU.

 

If nothing happens, everybody happy.

 

Battery soaks up any electrical transient spikes like a sponge.

 

It is only damaged by consistent high voltage from the alternator, 16V and above.

This is basically boiling the battery.

Regular lead-acid battery contains 1/3 sulphuric acid and 2/3 water.

The water will be boiled off, leaving the battery extremely hot, and prone to explode.

 

I also think so. 

[Kklee]

Yes and more than that.

I will never let my car engine run without a battery

Dont even say to drive

Would you?

 

A started car will die when the battery is fully disconnected.

Even if it doesnt dir instantly, it will after a while.

 

Maybe bikes and cars are different.

But my bike was like that.

 

Sometimes is not by choice.

Like I got an experience, my battery short circuit.

The voltage fluctuates between 9v and 16v.

Of course if i don't know about the voltage fluctuations, I may just restart the car when it dies, all the way to the workshop.

Sometimes better not to know. 

 

I really don't know which are the cars that will die or won't die, but so far, I got see one car didn't die.