Technical Alternator choices

[SUKUMAR KRISHNAN]

Hi, I own a Punto Grande 2010 model and was factory fitted with a Denso 105amps Alternator. The alternator is defective and cannot be repaired, I managed to source a Denso Alternator also meant for Punto but the problem is its only 90amps all other specification like voltage is same.
Any issues if I fit this alternator in my Car
Thanks regards Sukumar

 

[Eklipze3k]

Hi and welcome.

The 90amp alternator will work, but it will struggle when lots of the car's electrical systems are working at once. This will cause the battery to eventually stop charging as the alternator won't be able to provide enough current to run all the systems and charge the battery. If it's urgent, get the 90amp but replace it with a 105amp or higher rated as soon as possible to prevent permanent damage to the battery.

 

[DGPunto]

I'd think you should be fine unless you drive lots of short journeys with all the electrics on

 

[Bernievarian]

Very roughtly 12ish volts x 90 amps is 1080 watts. 200 watts for all lights, there is still about 900 W for power steering (far from 100% duty cycle) and various electric/electronic consumers, so as DG-P said, unless you'd do the milk-man drive at night in winter, you should be fine with that alternator...

BRs, Bernie

 

[DGPunto]

Maybe it's me being old but it's not that long ago when alternators were rated at 30-40 amps.

 

[Bernievarian]

Maybe it's me being old but it's not that long ago when alternators were rated at 30-40 amps.

Guess you've even seen 6 volts dynamo and positive earthed cars .. ?

BRs, Bernie

 

[DGPunto]

Guess you've even seen 6 volts dynamo and positive earthed cars .. ?

BRs, Bernie

Haha yes my first car (a very old Mini) had a dynamo - though it was a 12v one!

 

[aurick86]

Should not be a problem unless you have "start-stop" system.

 

[flisko]

Hi and welcome.

The 90amp alternator will work, but it will struggle when lots of the car's electrical systems are working at once. This will cause the battery to eventually stop charging as the alternator won't be able to provide enough current to run all the systems and charge the battery. If it's urgent, get the 90amp but replace it with a 105amp or higher rated as soon as possible to prevent permanent damage to the battery.

for car to draw 105amp wouldnt it need like a lot of stuff to be on at the same time
ac speed 4, city, fogs, high beams, both wipers...