Batteries

Question 1

AH

Answer 1

Amp Hours - the amount of steady current the battery can supply for 20 hours without the battery voltage dropping below a certain level.

Question 2

RC

Answer 2

Reserve Capacity - the number of minutes a battery can sustain a 25A draw before dropping below 10.5V

Question 3

CCA

Answer 3

Cold Cranking Amps - the amount of current a battery can supply for 30 seconds without the battery dropping below 7.2V

Question 4

A 100 AH battery will supply ____ for 20 hours?

Answer 4

5A per hour

Question 5

A 200 AH battery will supply ____ for 20 hours?

Answer 5

10A per hour

Question 6

A 50 AH battery will supply ____ for 20 hours?

Answer 6

2.5A per hour

Question 7

Lead acid battery

Answer 7

Lead plates in liquid electrolyte (sulphuric acid).

Question 8

Calcium battery

Answer 8

Calcium added to + and - lead grids.

Question 9

Hybrid battery

Answer 9

Calcium added to neg lead grid. Combine benefits of conventional lead acid and calcium batteries.

Question 10

Gel battery

Answer 10

Gel electrolyte embedded in separators. Don’t need to be kept upright.

Question 11

AGM battery

Answer 11

Absorbed Glass Mat. Electrolyte absorbed into and stored by the glass mat separator.

Question 12

If two 6V batteries were connected in parallel, what voltage would be produced?

Answer 12

6V

Question 13

If two 6V batteries were connected in series, what voltage would be produced?

Answer 13

12V

Question 14

The more plates a battery has the higher _____?

Answer 14

More plates = more amps

Question 15

Deep cycle batteries are rated in ____?

Answer 15

AH - Amp Hours

Question 16

3 main types of battery chargers

Answer 16

Constant voltage, constant current, smart charger

Question 17

Constant voltage charger

Answer 17

Supplies current to the battery based on potential voltage difference - when there is a big difference between the battery voltage and the charger voltage supplies high current which begins to taper off as the battery charges and the difference is reduced.

Question 18

Constant current charger

Answer 18

Varies voltage applied to the battery in order to maintain a constant current

Question 19

Smart charger

Answer 19

Charge in 3 stages: bulk, absorption, float

Question 20

Re charging, define Bulk

Answer 20

Current sent at maximum safe rate until battery voltage is at approx 80% capacity then charger begins absorption stage

Question 21

Re charging, define Absorption

Answer 21

Charging voltage is held constant while current is sent based on the battery’s voltage. When the battery is fully charged the charger begins the float stage.

Question 22

Re charging, define Float

Answer 22

Charging voltage of equal to slightly more than battery capacity is maintained while current flow is very low. This is to keep the battery charded while it is not being used..

Question 23

Fast charging

Answer 23

Charges quickly by supplying large amount of voltage and current. Can overheat. Best used when battery low on charge but has to be fitted soon. Battery MUST be in good condition to charge this way - never perform on battery with sulfation buildup or separator damage.

Question 24

Trickle charging

Answer 24

Application of low current over long time. Unlikely to overheat battery. More likely to fully charge battery. Only safe way to charge a sulfated battery.

Question 25

Order of connection for jump charge cables

Answer 25

Pos dead, pos donor, neg donor, ground on dead car AWAY from intake manifold and fuel lines.

Question 26

After jumpstarting, what should be done before removing the cables?

Answer 26

Once started, the dead car should be run for a while with its headlights on. Helps stabilise voltage between the dead battery and the donor battery which reduces risk of a voltage spike when cables are removed (spike can harm the electrical system).

Question 27

Testing the battery voltage with no loads on the battery is called what?

Answer 27

Static voltage test

Question 28

A voltage drop test does what?

Answer 28

Measures the difference in voltage between 2 points on a circuit.

Question 29

To test the battery under load, what 2 (or 3) things should be turned on to apply the maximum load?

Answer 29

High beams and rear demister (or turn blower motor on full)

Question 30

What is the minimum voltage a battery can drop to when tested under load?

Answer 30

9.6V

Question 31

If a battery drops below 9.6V when tested under load what should be done?

Answer 31

Charge and retest. If it still fails the test then replace it.

Question 32

Unwanted current drain is called what?

Answer 32

Parasitic drain or dark current

Question 33

Steps to find which system causing parasitic drain

Answer 33

Confirm drain. With multimeter still hooked up, begin removing and replacing fuses one by one. When removing a fuse causes the multimeter reading to drop, you have found the system with the issue.

Question 34

Test to determine whether there is a parasitic drain

Answer 34

Make sure vehicle is asleep and all loads are off (inc bonnet open switch. Check multimeter leads and fuse rating. Disconx neg battery terminal. Put multimeter between neg battery post and terminal. Wait 5 min and check amp reading - should be less than 0.05A. If not, there is a parasitic drain.

Question 35

Approx max current drain for a vehicle with all loads off and systems sleeping

Answer 35

0.05A

Question 36

7 main automotive battery types

Answer 36

Lead acid, calcium, hybrid, gel, AGM, lithium-ion, lithium-ion phosphate

Question 37

What is the % of acid to water in the electrolyte of a flooded battery?

Answer 37

Approx 20-40% acid to approx 60-80% water

Question 38

If unable to locate parasitic drain via fuses what are 4 other things to check?

Answer 38

Starter motor (no fuse), definitely no key in or near car (check for spares e.g. in glovebox), where is customer storing key at home, is car near pylons or solar panel invertors (can produce radio waves which prevent sleeping).

Question 39

A battery is fully discharged so a charger isn't working on it. List 4 steps to get it to charge OR an alternative charging method.

Answer 39

Remove dead battery from car. Attach charger cables. Use donor battery to jump start dead battery. Keep jump leads attached for several seconds until charger kicks in. Charge as normal. OR, use a smart charger which sends a small current into dead battery to "excite" it so it will charge.