Batteries

Out of Sight Out of Mind?

 

By:  Andy Wiedeman

Member of the Rocky Mountain A’s of Colorado

December 2007.

 

This research paper is intended to provide basic information on automotive batteries and the charging system for the Model A Ford built between the years 1928 and 1931, however, as much of  the information is general in nature it applies to automotive  batteries of all types.  

 

The Model A Ford was delivered from the factory with a positive grounded 6 volt battery that had an 80 Amp Hour capacity.  The Model A battery was the same battery that Ford had used on its Model T from 1919 to 1927.   The battery was charged in the vehicle by a two pole 3rd brush type generator which delivered its maximum current about 1200 rpm then tapered off as the speed of the engine increased.  At rest the generator was disconnected from the battery by a mechanical relay (the “cutout”)  which was activated above about 700 rpm.  The Model A did not have a voltage regulator, therefore the battery was prone to overcharging.   The charging current was manually adjusted seasonally, or by special needs, by the owner according to his driving conditions.

 

Owners of restored Model A Fords have several options available to them to keep their batteries fresh and increase their battery life.  This report discusses options for improving the battery charging system, while keeping the “authentic look” of the Model A generator.   

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This report has the following information:

·     Battery types, ratings and what they mean,

·     Quantifies, the original Model A Ford battery capability versus temperature.

·     How to set the original Model A charging system to minimize overcharging

·     How to eliminate battery overcharging and extend Model A battery life

·     How to improve the Model A charging system

·     How to select between using a generator or an alternator

·     How to store and maintain a Model A battery - Winterizing

·     Battery charging techniques, jump starting and testing for state of charge and capacity

·     Provides information on replacement batteries

·     Included is a short history of  automotive electrical generation, and the evolution of modern charging systems

 

Table of Contents

 

Introduction.. 5

Introduction.. 5

General Battery Information.. 5

Battery Basics. 6

Typical Automotive Battery Design. 6

The Original Model A Ford Storage Battery.. 7

The Original Model A Ford Battery Design. 8

The Original Model A Ford Battery Capacity. 12

The Original Model A Ford Recharging Time Versus Temperature. 15

Battery Life. 18

Longer Life with Electrolyte Level Checks. 18

Longer Life by Maintenance Charging during Winter. 19

Longer Life by Preventing Overcharging. 19

Generator Charging Rate Settings to Prevent Overcharging.. 20

The Model A Instruction Book Information on Battery Charging Rate. 20

The Ford Motor Company Service Bulletins on Charging Rates. 21

Other sources of Information on Generator Charging Rates. 23

Summary of Battery Charge Rate Recommendations. 25

Driving and Touring Settings for the Restored Model A.. 25

Semi-Charge Regulation. 26

What to do About Overcharging?. 32

Generator or Alternator … What are my Choices?. 33

How to Choose A Solution to Overcharging.. 34

Typical New Restoration. 34

Older Existing Restoration. 35

New Touring Restoration. 35

Battery Voltage. 35

State of Charge versus Battery Voltage. 35

Check and/or Improve Your Battery Connections. 36

Ways to Increase Battery Voltage or Capacity. 37

Battery Ratings. 38

Battery Capacity Ratings. 39

Battery Reserve Capacity. 39

Battery Cranking Ratings. 39

Types of Batteries. 40

Flooded Electrolyte Types. 40

Absorbed Glass Mat Type. 41

Gelled Electrolyte Type. 41

Automotive Battery Operation.. 41

Charging Batteries. 41

Battery Charging Voltage Set Points. 42

Battery Charging Current Rate. 42

Battery Chargers. 43

Battery Maintenance Charger System for the Model A.. 43

What about Power Converters?. 44

Maintenance and Safety.. 46

Care and Maintenance. 46

Battery Safety Procedures. 46

Battery Testing.. 48

State of Charge Tests. 48

Battery Capacity Testing. 49

Battery Charging in the Vehicle. 50

Safest Charging Method. 50

Quick Charging Method. 51

Jump Starting.. 51

Battery Storage. 52

Winter Storage. 52

Appendix 1 … Battery Availability.. 53

Appendix 2 …  Capacity versus Discharge Rate. 54

Appendix 3 …  Voltage Regulators & Alternators.. 56

Voltage Regulators. 56

Cover Band Mounted Internal Generator Voltage Regulator. 56

Cutout Mounted Generator Voltage Regulator. 57

Suppliers of Voltage Regulators. 57

Alternators.