Battery Gauge 12v?
 
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Battery Gauge 12v?

 

Celso Costa
(@celso-costa)
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Hi all, I am studying the convertion of a Chevy 1938 to 12v.  Not decided yet. I could not find anywhere if it is necessary to put some sort of resistor or stepdown in line with the battery gauge. Nobody mentions it. There are only comments about the fuel gauge. Does it work without any adaptation? Thanks.


   
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Tiny
 Tiny
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The ammeter doesn't care about voltage. It does however, care about amperage. If you're going to step up the voltage you're also probably going to step up the amperage output of the charging system. Pounding a lot of amps through an ammeter made for 30 amps can damage it. I speak from experience. I stayed 6v but put a 6v alternator on my 38. It's a 60 amp alternator. A couple of hard starts later, with the alternator pounding 60 amps through the ammeter trying to re-charge the battery, and my stock ammeter was ruined. I picked up a spare in case my son wants to go back to the generator after I pass and the car becomes his but for now it's on the shelf. I did locate a 6v volt meter so that I can tell if it's charging. Having said all that, yes, if you're going to increase the charging system amperage you'll need to protect the ammeter.

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Stovblt
(@ole-olson)
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I agree with what Tiny says, but would add a little.

Take notice of the fact that Tiny did NOT convert to 12 volts.

I have several 6 volt vehicles, all of which start and operate just as well as my 12 volt vehicles.

Can we ask WHY you want to convert to 12 volts?

 

Ole S Olson
Saskatoon, Sask, Canada
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Celso Costa
(@celso-costa)
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Thanks. Just considering the idea, as I am about to check the electric system. Thank you for you comments about your 6v cars. In relation to amperage, it should go down. This why cables in 12v cars do not need to be as thick as the ones in 6v system (but I may be saying something silly here...).


   
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Tiny
 Tiny
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Posted by: @celso-costa

 In relation to amperage, it should go down. This why cables in 12v cars do not need to be as thick as the ones in 6v system (but I may be saying something silly here...).

In electrical theory you're dead on. Where the issue may come in is, most people who convert to 12v do so to power accessories. Those can draw considerable amps. Also think back to my personal example. The stock ammeter is designed for a max of 30 amps. If you put a 90 or 120 amp (voltage is irrelevant) alternator on the car, every time you start the car it's going to be pounding that amp load back through an ammeter not designed to handle even close to that load. If you put on a 40 amp alternator it's possible you won't have a problem.

 

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Save a life, adopt a senior shelter pet
1938 Master Business Coupe
1953 210 Sedan


   
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