1. Battery 101

2. Trojan Battery Company
Types of Construction
Lead Acid
Flooded
Sealed
(Valve Regulated)
Maintenance
Free
Absorbed Glass
Mat (AGM)
Gelled
Lead Calcium
Deep Cycle 50%
Cycles
Lead Antimony
Deep Cycle 80%
Cycles
High Power
Cycles
Immobilized
Electrolyte
Low Power
Deep Cycle 80%
Cycles 7

3. Trojan Battery Company
Terminology
Watts = Volts x Amps = POWER
Watt-hours = Volts x Amps x Time (hours) = ENERGY
Amp-Hours = Amps x Time(hours)

4. Trojan Battery Company
How a Lead Acid Battery Works
Discharge
PbO2 +
Pbo +
2H2SO4
2PbSO4 + 2H2O
Charge
(Positive)
(Black/Dark
Brown)
(Lead
Peroxide)
(Negative)
(Gray)
(Sponge
Lead)
(Electrolyte)
(Lead Sulfate)
(Water) 8

5. Trojan Battery Company
Definitions
Voltage (V) = Electromotive force
(potential of battery) + -
6.3V
Open Circuit Voltage?
Under Load Voltage?
12V vs. 6V?
Trojan
2.1 Volt Cells 9

6. Trojan Battery Company
Voltage Relationships
Open Circuit Voltage » Specific Gravity
Specific Gravity » State of Charge
Specific Gravity = Open Circuit Voltage 9

7. Trojan Battery Company
Open Circuit Voltage
OCV or VOC: Voltage measurement made after
24 hours of battery rest (no load).
OCV vs. State of Charge (SOC)
Charge
Level
Specific
Gravity
Voltage
(12)
(6)
100%
1.277
12.72
6.4
75%
1.227
12.42
6.2
50%
1.172
12.12
6.1
25%
1.111
11.76
5.9
Discharged
1.098
11.58
5.8 13

8. Trojan Battery Company
Typical Discharge Curve
at a Constant Discharge Current
Resistance
Voltage
Drop
Open Circuit Voltage
Voltage Under Load
Coup De Fouet
End of Discharge
Voltage
VPC
Voltage
Measured Capacity
Time ®
IEICC

9. Trojan Battery Company
Deep cycle
Amps/100AH (C20*)
Charge Current
VPC*
1 - 3 Amps/100AH (C20*)
Volts per cell
(80% DoD*)
Charge Voltage
Charge Time ®
IEICC

10. Trojan Battery Company
Series/Parallel Circuits
In a Series Circuit, Voltage is additive, Current stays the same
Example: 2 T-605’s in series = AH
In a Parallel Circuit, Current is additive, Voltage stays the same
Example: 2 T-605’s in parallel = AH

11. Trojan Battery Company
Definitions + - + -
12V
(12V, 220 AH)
Series Circuit
Voltage is additive
Current is equal + +
Parallel Circuit
Voltage is equal
Current is additive + 6V - - -
(6V, 440 AH) 10

12. Trojan Battery Company
Battery Capacity
A battery’s capacity is the amount of electricity
the battery can provide to the load and is
dependent upon the rate (speed) at which the
battery is discharged.
20 hour rating = 100% Capacity
8 hour rating = 88% Capacity
6 hour rating = 84% Capacity
3 hour rating = 74% Capacity
1 hour rating = 59% Capacity 12

13. Trojan Battery Company
Amp Draw Vs. Run Time (Hours)

14. Trojan Battery Company
Temperature vs. Capacity
Capacity %
Temperature (°F)
IEICC

15. Trojan Battery Company
Generic “Smart” Charge Curve
Voltage
Current
(VPC)
(A)
current
2.60
C20/5
2.37
voltage
C20/50
20%
80%
100%
State of Charge (%)
IEICC

16. Trojan Battery Company
Stratification
Specific gravity gradient that may result from
ineffective overcharging.
1.080
Normal Sp.G. = 1.277
(Full Charge)
1.400 15

17. Trojan Battery Company
SAFETY
Protect eyes and skin from exposure to electrolyte.
Don’t smoke when working around batteries or while charging.
Insulate tools to prevent shorting across the posts.
Use good lifting mechanics when moving and installing batteries.

18. Trojan Battery Company
SAFETY
Neutralize acid spills with baking soda or soda ash, IMMEDIATELY.
Ventilate during charging to prevent gas build-up.
Charge with vent caps securely in place.
When in doubt, contact your dealer.