Which Battery?

[parrish]

IM going to replace the battery on the 131, i notice that the battery fitted is 2 inchs short of filling the tray.
Can anyone tell me which battery is the best  with a high cold crank capability and will fill the tray?
Steve

[miro-1980]

Steve,

I would really suggest you go to a specialized battery dealer. They can check your alternator amp rating and charging voltage and suggest what you need. 

The external dimensions are not really so important.  Use of  a specific  battery is really determined by several factors: what alternator you have , what is the charging voltage, if you use headlights every day during daylight ( as required all year in Sweden and Poland ) , how often you drive the car , long or short distances, do you perform regular maintenance of your batteries , charge them , etc.

I use a standard battery (the kind you can open the cells and check charge level and add dematerialized water) if required.  Not sure what is is its cold cranking rating and what amp/h rating.

If you select a very high amp/h rating your alternator may not keep it charged sufficiently , and if too small it will "boil" the battery overcharging it (risk of explosion) due to hydrogen gas being produced by charging it too much.   

So keep these elements in mind when selecting a battery.

I would also suggest that  you get yourself a starter with high gear ratio.  Starts more easily by producing higher starting RPM and uses less juice to do so. Incidentally it also weights half of a standard starter.

Miro         

[131DHOC]

This is because airconditioned cars have bigger battery (55Ah instead of 45Ah) and fill the tray. Usually standard 131 fit 45Ah battery and unless you live in a cold and dark place it will be enough.

[parrish]

Miro,
Thanks for the information,
where can i get a starter with high gear ratio?
Steve

[Thotos]

If you select a very high amp/h rating your alternator may not keep it charged sufficiently , and if too small it will "boil" the battery overcharging it (risk of explosion) due to hydrogen gas being produced by charging it too much.  

No Miro, sorry, that's wrong. The charging voltage in a car does not vary (unless there's a fault in the regulator) and it's typically fixed at between 13.8 volts and 14.4 volts. The charging current will vary according to the alternator's output and the battery's requirements. The battery's current rating is the amount of current the battery can deliver and has nothing (or very little) to do with the charging current. Otherwise little 4 Amp battery charges would never be able to charge a 'large' battery.

There's a lot of power needed to crank a Fiat twin cam engine and hence the 2 litre twin cam Fiats are fitted with a 1.6KW starter motor that will need at a minimum 130 Amps of cranking current. Car batteries normally give you two specification figures:

1. Capacity rated Ah (ampere hours) which is the length of time in hours the battery will last if 1 amp is drawn from it.

2. 'Strength' rated in Cold Cranking Amps (CCA) which is the amount of current a battery can provide at −18 ?C for 30 seconds.

Steve, you should get a battery that will give you at a minimum 40 Ah and preferably nearer to 60 Ah and a CCA of at  least 400, preferably over 500.  

The recommended battery for a 131 is an 078.

 

[sid131]

Jim Mcguigan is the best man to get you a chape battery

[131DHOC]

in my service instructions 1,1Kw starter motor for 2000tc is quoted and not 1,6Kw, I don't think things were different for north European cars.

[Thotos]

You are probably right; my memory is not what it used to be    Still, 1.1 KW is a lot. The smaller engined OHV cars had a 0.8KW starter I think and Japanese cars have them as low as 0.4KW.

[alan.acs]

Thotos is right except for the kw for the starter motor which is indeed 1.1kw.

Also a point missed is that when the car is running its the alternator that runs all of the cars electrics
and the surplus goes to charge the battery.

[sid131]

Jim Mc Guigan  will sort youse out

[jasonh131]

Ive got a HCB075   
http://www.halfords.com/webapp/wcs/stores/servlet/product_storeId_10001_catalogId_10151_productId_264105_langId_-1_categoryId_165762
  calcium one and the stick on the battery is even more 620 amps  and expensive
 good job it was all ready on the car 

[Thotos]

I too have an 075 battery (from my Gamma  ) on my 131 at the moment but while it can be made to fit, the poles are the wrong way round for the Fiat. The 078 battery is the same dimensions with the poles the correct way round for the 131.

[miro-1980]

Thotos , I stand corrected.

 I would however submit that my experience suggests that the amp rating of the alternator must match both electricity use in the car as well as the capacity of the battery. Does this make more sense or should I take my Basic Electricity 101 class again     

Miro

[miro-1980]

Miro,
Thanks for the information,
where can i get a starter with high gear ratio?
Steve

I got it from Allison Autmotive. Contact Mark at allison1565@verizon.net.

I have bought my gear reduction starter for 131 2.0 liter engine at $225 plus shipping , which I believe is a real bargain. Actually I will buy one more for my 124 spider, later this year.

Miro     

[mirafioriman]

The alternator must be able to produce enough current to satisfy the demands placed on it by the running engine and accessories in the car. The battery size must be sufficient to start the car successfully and to a certain extent provide current for the accessories even though the alternator will be running these most of the time when the engine is running.

If you car is standard then obviously the standard rated alternator and battery should be fine. If you start adding stereo equipment, extra lights and so on then perhaps it is time to consider upgrades.