One For Any Auto Electricians Out There..

[Impret-Sir]

My Focus ST needs a new alternator. Looking online I have seen ones advertised as suitable for my cars engine and age rated at both 150A and 120A. The OE one is 120A. Oddly, the 150A ones are quite a bit cheaper than the 'weaker' ones. So, would it be OK to fit a 150A one in place of the 120A that it has now?

[Ryzen]

It wont make any difference as the output voltage will be the same.Are they both from the same manufacturer?

[Hymie]

Go for the cheaper 150A version, with a rating of 150A it will re-charge the battery quicker than the 120A version – if you are hanging loads of extra electrics on the vehicle it will keep the battery fully charged, despite the extra drain on the system.

[Impret-Sir]

Thanks both for your answers. The mechanic who is doing the work expressed concern that the more 'powerful' unit might overload other components, or even cause problems with the cars wiring.

[Leegallacher3]

Probably a bit late to answer this but I can understand the concern of the mechanic. However I’d still go with what’s previously fitted as it’s been fitted for a reason.

[Impret-Sir]

Thanks to all for your answers. I have discovered that the more powerful unit was fitted to cars with the optional heated seats, which mine is not, otherwise the cars are identical, so I could have opted for the cheaper more powerful one, oh well, you live and learn I suppose!