Sanjeev Sabhlok's notes on technology, hardware, gardening

Car battery charging – key principles – and the CTEK 12v 5A charger that I’ve now bought

MANDATORY REQUIREMENT TO CHARGE BATTERY EVERY WEEK

I’ve now bought 62456370890N-60B24L/JE : Panasonic 12V Car Battery (screenshot dated 21 march 2019) for $188.95. It has a four year warranty.

  • Model No.: N-60B24L/JE
  • Capacity 20hr: 45Ah
  • Size : 202 H (227b including posts) x 128 H x 238 W
  • Electrolyte Density: 1.28 at 25 degrees C
  • CCA: 410
  • RC: 70min
  • Class: A

REGULAR MAINTENANCE CHARGING IS ESSENTIAL!

I’ve been advised that since the car does a lot of short distance travelling, it is best to charge the battery EVERY WEEK.

This is confirmed here.

Batteries have a natural self discharge or internal chemical leakage; and today’s cars draw a tiny amount of power from the battery when not in use to keep all the electrical systems ‘alive’. Over time, the battery will become fully discharged if not driven.

To avoid this happening, you can connect a maintenance charger to keep your battery in good condition.

FURTHER: The best way to maintain a battery on extended holidays is to use a maintenance charger. It can be left connected for an indefinite period, ensuring your car battery remains fully charged while you are away.

ISSUE THAT STARTED MY INVESTIGATION: BATTERY IN MY TOYOTA COROLLA was diagnosed with 10 volt charge by RACV.

The battery had been installed by RACV some time ago

UN2794 BATTERIES WET FILLED WITH ACID

Cold cranking amps (CCA): 430
Amp hours (Ah): 45
Reserve capacity (RC) 71 minutes

It is a calcium battery. lead acid calcium / calcium. I need a CHARGING MODE charger.

NEVER USE RACV BATTERY REPLACEMENT SERVICE.

These people provide a budget battery and no advice on how to maintain it. Their batteries DON’T go very long. And they don’t provide any useful advice on battery maintenance.

WHAT IS THE VOLTAGE OF A FULLY CHARGED CAR BATTERY?

“Fully charged automotive batteries should measure at 12.6 volts or above.” [Source]

The voltage of a battery is a good way to determine the state of charge. Here’s a handy table with the breakdown: [Source]

State of Charge Voltage
100% 12.7 – 13.2
75% 12.4
50% 12.2
25% 12.0
Discharged 0 – 11.9

If your battery is:

  • Reading 0 volts, chances are the battery experienced a short circuit
  • Cannot reach higher than 10.5 volts when being charged, then the battery has a dead cell
  • Fully charged (according to the battery charger) but the voltage is 12.4 or less, the battery is sulfated  [This is what seems to have happened in my case]

CTEK charger

Given the urgency I purchased a CTEK charger

BACKGROUND

What is a “Calcium” battery?

A Calcium battery is a still a lead acid battery; they are usually sealed maintenance free.  Calcium replaces antimony in the plates of the battery to give it some advantages including improved resistance to corrosion, no excessive gassing, less water usage and lower self discharge.  Silver is another additive used by some manufacturers, the addition of silver enables the battery to be more resilient to high temperatures.

Calcium batteries require a higher charge voltage than conventional batteries.  If used in a deep cycle situation it is advisable to use a charger designed for calcium batteries of has a calcium charging mode to get the maximum life out of the battery.

HOW TO TEST USING HEADLIGHT

Fully charged automotive batteries should measure at 12.6 volts or above. When the engine is running, this measurement should be 13.7 to 14.7 volts. If you don’t have a multimeter to tell you the voltage of your battery, you can do a test of your electrical system by starting the car and turning on the headlights. If they are dim, that indicates the lights are running off the battery and that little or no charge is being produced by the alternator. If the lights get brighter as you rev the engine, it means the alternator is producing some current, but may not be producing enough at idle to keep the battery properly charged. If the lights have normal brightness and don’t change intensity as the engine is revved, your charging system is probably functioning normally. If you’ve been experiencing problems with your battery system and the headlight test checks out okay, you should check whether or not the battery is holding a charge, or if something on the vehicle is discharging it. [Source]

 

THIS IS VERY USEFUL

HOW TO RECHARGE A DEAD CAR BATTERY SAFELY AND QUICKLY

if the unit in question reads below 12 volts. Using the alternator to deal with such a depleted battery can actually damage your alternator.

 

 

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Dewalt DCD734 cordless drill TYPE 1 14.4 volts

I’ve got this – DCD734-XE drill driver 14.4 volts type 1. Instruction manual.

Plus two batteries and battery charger.

The drill is fairly sturdy but can’t do as well as an 18v drill. Most cordless gadgets now are 18 volts so this one needs to be discarded after its batteries give out.

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Triton XTRJSB Reciprocating Saw – how to use

This. The Manual here.

Some blades that I have. These are stored IN THE TRITON IMPACT DRIVER BOX

The first of these is 14TPI and can cut some metal. The second one has very low TPI (7) and is therefore suitable only for wood.

Blade types

Blade strength is measured in TPI (teeth per inch). For low grade material like wood low TPI (6 or so) is enough. For high grade material (like metal) more teeth are needed per inch (around 18).

How to use it:

Just twist the front part of the tool as far as it will go, insert the blade and release. The blade should hold firmly.

This video is for ryobi but is useful for the Triton as well.

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