Battery Voltage up & down

[Tigershark1976]

Tigershark1976,

 

Dun worry, I'm a very safe driver, never involved in any kind of accident for the pass 20 years.

 

My Blitz's LCD is very big and the reading is almost 1cm font size.

 

hmm.. bro, did u reply to the wrong person?? i didnt comment anything abour your driving style/ habbit/ experience ahh...

[Mini-itx2010]

Why not call it a Dynamo?

 

They all meant the same thing. Alternator, Dynamo, generator.

 

The slight different in the name is that dynamo usually refers to a small generator thats generating DC current using a commutator (much like a small DC motor working in reverse).

 

Alternator is device that produces AC current (alternating current hence alternator). It usually has the magnet in the center and coils surrounding it.

 

generator (more specially electrical generator) is a general term for anything that converts some form of energy (usually mechanical, like rotational) into electrical energy. Some can be heat as well. eg. peltiers. Using peltier effect to generator electricity.

[Tigershark1976]

Good-Carbuyer,

 

I think it is not common, do notice the voltage is dropping during speed up and increasing during slow down.

 

It shall be the other way right?

 

 

the batt voltage fluctuate due to alternator kicks in and cut off, got nothing to do with speed..

[Jchuacl]

What about Honda cars? Does it work along the same line of engineering?

 

 

Since you are driving Toyota post-2002 model, the Denso alternator has VARIABLE LOAD RESPONSE function built-in.

 

I gather from what I read is that the vehicle alternator voltage supply and charging cycle is determined by engine load, rpm, speed and battery current sensor feedback through the main ecu.

 

It is part of Toyota design engineering to get better fuel economy for *** star ratings.

 

That is why it is not advisable to anyhow install earthing wires just because shop sells them to you. It skewers the signal sent back to ecu which determines alternator action.

 

Reason why PIVOT after being complained about failing batteries, erratic charging and poorer car performance that they had to release a product notice pivot earthing problem

 

Hope this helps explain a little more.

 

[Mini-itx2010]

the batt voltage fluctuate due to alternator kicks in and cut off, got nothing to do with speed..

 

Thats does happens for old cars though w/o variable load control (basically just a on/off unit). When engine at idle, voltage will be lower. then rev till ~2200RPM then will hit around 14.5V.

 

The manual also says must rev the engine and measure the voltage, at idle, the alternator is not spinning fast enough, hence voltage will be lower. Of course, there is heat factor as well. As the alternator gets hotter, voltage output will drop as well. It can drop as much as 0.5-1V.

[Smhomie]

I believe they do since theirs is NipponDenso as well in that sense. It seems they sometimes change between Denso and Hitachi suppliers.

 

For Honda, they coin it "Idle Stop System technology".

 

Most jap cars now adopt such measures as part of fuel efficiency ideal goal except Subaru that seems more performance-centric in their approach.

 

Alternator activities can affect vehicle fuel economy by as much as 2% variance.

 

Without this technology to govern/control alternator activity, we would be burning more fuel through engine loading since all drivers switch on air-con (added load), except for the cabriolets

 

 

[Jchuacl]

I've heard that in order to resolve the issue of gears which could not be changed up for Alfa Romeo Selespeed cars, you need to whack the side fender so as to loosen up the hydraulic value which was located around that area.

 

 

Yr mech behave like my friend late grand aunty, she solve our family washing machine erratic rotation problem by kick fee times. It works

 

[Jchuacl]

Thanks for the info.

 

You mention that Subaru is the exception, are you saying that it is across all their models including those models which are not TC?

 

 

I believe they do since theirs is NipponDenso as well in that sense. It seems they sometimes change between Denso and Hitachi suppliers.

 

For Honda, they coin it "Idle Stop System technology".

 

Most jap cars now adopt such measures as part of fuel efficiency ideal goal except Subaru that seems more performance-centric in their approach.

 

Alternator activities can affect vehicle fuel economy by as much as 2% variance.

 

Without this technology to govern/control alternator activity, we would be burning more fuel through engine loading since all drivers switch on air-con (added load), except for the cabriolets

 

[Ariba]

@Marcostan Hi bud, did you manage to solve this? I’m having the same issues and looking for the solution.

[Ct3833]

1 hour ago, Ariba said:

@Marcostan Hi bud, did you manage to solve this? I’m having the same issues and looking for the solution.

He already said he turns on high beam, i dont know why he has to turn on high beam if he was  driving in SGP.  High beam is sucking out all the electircity. Anyway the  so called battery voltage reading , when you drive , will be the alternator charging reading  and  will fluctuate from time to time. What is important is the reading when you switch off your engine, it has to be about 12.5v. 

[inlinesix]

4 minutes ago, Ct3833 said:

He already said he turns on high beam, i dont know why he has to turn on high beam if he was  driving in SGP.  High beam is sucking out all the electircity. Anyway the  so called battery voltage reading , when you drive , will be the alternator charging reading  and  will fluctuate from time to time. What is important is the reading when you switch off your engine, it has to be about 12.5v. 

I used hi beam in MSCP.  My car is black colour and the beam is quite low for SUV.

[boonhat_91]

Hi all, asking a kiam kana question.. Usually when battery is flat, people will jumpstart and quickly drive to a battery shop to replace asap.. If I have one of those portable jump starter, is it actually possible to keep jump starting the car instead of replacing the battery asap? And how long can I keep beating this dead horse?

I know a new battery is not expensive in the grand scheme of car ownership, just asking out of curiosity.

[badlammy]

Possible, but you'll just be testing your luck. You cannot jumpstart if when your battery becomes completely flat.

[Mkl22]

On 4/3/2024 at 10:07 AM, boonhat_91 said:

Hi all, asking a kiam kana question.. Usually when battery is flat, people will jumpstart and quickly drive to a battery shop to replace asap.. If I have one of those portable jump starter, is it actually possible to keep jump starting the car instead of replacing the battery asap? And how long can I keep beating this dead horse?

I know a new battery is not expensive in the grand scheme of car ownership, just asking out of curiosity.

as many times as possible you can jump until the battery becomes a true parasitic load and drags down even what the alternator is pumping out. then your sensors go haywire. but for a pure carburettor car, the limits are even lower.

[Blueray]

on average we start car 5 - 6 times a day, every time also jump start ... seriously ? 

[mersaylee]

On 4/3/2024 at 11:46 AM, Blueray said:

on average we start car 5 - 6 times a day, every time also jump start ... seriously ? 

No lah...oredi caveat kiam kana curiosity...all for paper knowledge...😁

[Kklee]

On 4/3/2024 at 10:07 AM, boonhat_91 said:

Hi all, asking a kiam kana question.. Usually when battery is flat, people will jumpstart and quickly drive to a battery shop to replace asap.. If I have one of those portable jump starter, is it actually possible to keep jump starting the car instead of replacing the battery asap? And how long can I keep beating this dead horse?

I know a new battery is not expensive in the grand scheme of car ownership, just asking out of curiosity.

IMHO.
The battery usually is for starting the car only and after that, the alternator takes over.
If the battery cannot hold charge,  the alternator will still try to charge it and may result in poorer FC.
The battery could also be faulty which is a bit dangerous.  My experience, IIRC, was after jump started, 
the battery voltage swing from  below 9V to above 15V. while the vehicle was on the move. 

If always drive short distances, the battery may not have enough time to be fully charged.  So maybe can do stationary charging. 

Edited April 3, 2024 by Kklee

[boonhat_91]

Thanks all for entertaining my question. Just bought a portable jump starter recently so getting funny ideas..