Hallo everyone
I've replaced 3 batteries in my Mazda 2 2011 1.3 in past 2 years thinking it was the cheapest battery in country.
BUT now I've purchased meeter and it shows in cigarette lighter 12V when engine on and EVERYTHING OFF - but when I turn fan on level 3 or 4 (full on) it "triggers" about 14V.
setting fan on level 1 or 2 gives just 12V.

Is that indication alternator is dying or terrible quality battery?

thank You

 

If you are checking the alternator output under load then 14v to 14.5 v would be ok. If your battery or battery’s in your case keep failing then you need to check for a parasitic drain on the system.
if I have read your post correctly buying three batteries in three years surely they would have still been in warranty ?

 

Hallo there - thank you for reply.
Yes - battery was under warranty - the reason I said "I've replace them" not purchased 3 of them - ALL of them died - sometimes charge is under 12V like 11.5V (when NOTHING is turned on apart of engine) and then I think - that is the reason battery dying (staying at about 11.5V for year is not good?) but why under just Level 3 fan kick in charge to 14.0 or even 14.3V?

 

Just to be clear are you saying that the charging rate only goes up when you select level 3 on the fan setting?
what charging rate do you get when the headlights are on and the fan off? You should get around 14v - 14.5 volts with the engine rpm of around 1500 rpm?
I am not an auto electrician but a charging rate as low as you have looks like there could be a fault with the regulator part of the alternator I would be looking for somewhere to have it tested.
Are your battery connections clean and tight

 

1. Battery posts are 100% clean
2. I get 14+ Volts when Road Lights are on too - but 11.5 to 12V when something taking less energy like Parking Light Fan Level 1 or 2 - or Radio on
3. I've reminded myself I've purchased 40Ah ; Cold Cracking Amp (CCA): 340CCA --------- shop advise to purchase 60Ah 480CCA - but I do not use music while engine off - nor lights while engine off
Could this smaller battery be a problem Mazda car charges it only under high load (like Road Lights or Fan level 3 or 4?)

Thank you For help

 

I think you are buying a under powered battery and will likely to suffer failures as you have before, you should have taken the shops advice buying under powered battery’s to save money is false economy.

 

Seems your alternator isn't getting excited without a load. Maybe the internal voltage regulator is failing?

Here's idle, no load (well 11A): 14.62v at alternator, 14.2v at ecu.

 

How to test internal voltage regulator if failing?
What I've noticed is when under load I have over 14V and.......... drive I have over 14V BUT......... I when I slow down to 5MPH or stop - charging Voltage drops to about 11.8-12V for about 1 second and back to 14V again it can be even heard in slowing down fan speed - and this happening all the time - something like ECU knows I slow down/stopped and change charge level? Is it internal voltage regulator thing?