Batteries _ Battery Charging by malj


									Batteries & Battery Charging
• In this presentation we try to give you:

• An overview of lead acid batteries and how
  they work.
• An overview of Hawkins battery chargers and
  how they work together with some charging
• Some common battery charger problems.
  All Devices Using Lead Acid
Batteries Need a Battery Charger

• Regular supplementary charging with a battery
  charger extends battery life substantially.
• This results in an economic benefit to the end user
  for which he will pay.
     Our Battery Charger Range

• Domestic & Recreational Chargers
• Professional Chargers used commercially in all the
  Automotive and Agricultural sectors
• Fully Automatic Chargers used for standby and
  sealed batteries
                        Battery Types

• We deal with rechargeable Lead-Acid
  batteries only.

• 2 Fundamental Types
  – Engine Starting – Quick bursts of high
    current for a few seconds.
  – Deep Cycle – Prolonged discharges of low
               Battery Construction
• 2 Basic Types depending on plate

  – Flooded Cell - Usually allows water addition
    • Low Maintenance (Lead-Antimony)
    • Maintenance Free (Lead-Calcium)
  – Valve Regulated (VRLA) - Always Sealed
    • Gel Cell
    • Absorbed Glass Mat (AGM)
Amp Hours - A Useful Battery Term
• Ah – Amp Hours
    • This indicates the battery capacity. If a battery is
      rated at 100 amp hours, it should deliver 5 amps
      for 20 hours or 20 amps for 5 hours, etc. This is
      useful for deep cycle batteries.
    • An old rule of thumb is to choose a battery charger
      capable of delivering in amps, one tenth of the
      battery capacity in amp hours. eg For a battery
      with 100 amp hours capacity, choose a charger
      capable of delivering 10 amps. Some modern
      batteries may use C/5 & even C/3 & high tech
      batteries ask for 3 x C.
How Lead-Acid Batteries work
                            Battery Life

• In general, only 30% of lead –acid
  batteries sold attain a 4 year life.
• 80% of all battery failure is due to stale
  sulphation of the plates.
    Stale Sulphation – the Silent Killer
• Stale Sulphation is caused by

     • Storage without some energy input
     • Deep discharging an engine start type battery
     • Undercharging a battery
     • Heat - increases internal discharge
     • Low electrolyte level. The exposed portion of the plates
       will sulphate
     • Incorrect charging levels – cheap chargers cause
     • Parasitic drain – the load put on the battery in a standby
       mode – see below
                           Parasitic Drain
• Parasitic drain is a load put on a battery
  that has been switched off
     • Most vehicles today have clocks, alarm
       systems, engine management computers etc
       all of which may be operating without the
       engine running or when it is idling. This is
       parasitic drain.
     • The constantly low or flat battery caused by
       excessive parasitic drain will have a
       dramatically shortened battery life.
                             Battery Charging

• If you don’t put the energy used back into the battery
  soon after use, it will commence to sulphate which
  affects life and performance.

      • The vehicle’s alternator is a battery charger. It works well
        if the battery is not deeply discharged.

      • The alternator will usually maintain the battery’s state of
        charge at somewhere around 80% - see the following
        diagrams & charts.

      • Full state of charge is best achieved by using a separate
        battery charger when the vehicle is at rest.
Battery State of Charge vs Regulator Settings

                      Typical Regulator
         +/- 73%           Setting
        of capacity
                         Driving Patterns
Alternator Current Delivery ex Bosch SA

                     Engine idling
                 = battery discharging
                          Driving Patterns
Engine Speed : Idling as % of Driving Time
    What is a Battery Charger ?
• In simple terms, a battery charger is a device
  that applies a d.c. voltage across the battery
• If the applied voltage is higher than the
  battery voltage, energy flows into the battery.
• This continues until the two voltages are
  approximately equal. At this point the battery
  has been charged up to the capability of the
  Battery Charger Construction
• Good quality battery chargers should have
  the following fundamental components
  – Some type of transformer to reduce the supply
    voltage down to the nominal battery voltage
  – Some type of rectifier to turn the a.c. into d.c.
  – Some type of control over the output of energy to
    the battery
  – Some type of device that will fail safe & limit or
    prevent damage to the battery or the charger
          Battery Charger Types

• Battery Chargers are divided into three
  broad types:

          • Non-adjustable
          • Adjustable
          • Automatic.
 How to Select a Battery Charger - 1
1. Establish the battery’s capacity in Amp Hours
2. Look at the output current data on the back of the
   range of chargers (use the lowest current rating.)
3. Choose a charger capable of delivering a
   MINIMUM current in Amps equal to 10% of the
   battery Capacity. Eg for a 50Ah battery, choose a
   charger that can deliver at least 5 Amps
 How to Select a Battery Charger - 2
4. Is the battery sealed or refillable?
5. If it is sealed, you MUST use an automatic
6. If it is refillable, you can use an automatic,
   a manually adjustable charger or a non-
   adjustable charger.
7. A non-adjustable (trickle) charger cannot
   be left on a battery permanently.
 How to Select a Battery Charger - 3
8. A non-adjustable (trickle) charger will continue
    to trickle current into the battery as long as the
    battery voltage will allow this.
9. Over time, this trickle is quite capable of taking
    the battery in to the gassing stage where it will
    lose water and may suffer permanent damage.
10. All battery chargers except the automatics have
    to be monitored to prevent overcharging.
 How to Select a Battery Charger - 4
11. If the battery is not used very often – eg
    leisure application, boating, biking etc –
    leave it connected to an automatic charger
12. The automatic charger will keep the
    battery at optimum voltage for years if
    need be, ready to go at a moment’s notice.
Hawkins Non-Adjustable Chargers
• These chargers include the Power 4, the
  Power 6, the Power 8 and the Power 10.
     • These chargers all have similar charging
     • They are taper chargers which rely on the rising
       voltage in the battery to reduce the current into
       the battery.
     • They use fuses &/or thermal cut-outs for
     • The charging operation must be monitored from
       time to time to check on the battery’s state of
Power 4 Non-adjustable Taper Charger
         Power 4 charging 50Ah Raylite Battery
                                          This taper charger must be monitored

                  16.0                                            Eelectrolyte gassing             3.0

                                                                  but voltage still rising



                                                                                                         Current - Amps
Voltage - Volts

                   8.0                                                                             1.5

                   6.0                                           Current tapering off but still
                                                                delivering over 1a after 45 hrs


                   0.0                                                                             0.0
                         0   2   4   6   8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44
                                                         Time Hours
Power 10 Non-adjustable Taper Charger
Power 10 charging 12V Exide 628 50 Ah Battery
          This taper charger must be monitored

                                                            Voltage well into electrolyte
                                                           gassing stage: stable at +/- 15V
                     16.00                                                                                     8.00

                     14.00                                                                                     7.00

                     12.00                                                                                     6.00

                     10.00                                                                                     5.00
       Voltage (V)

                                                                                                                      Current (A)
                      8.00                                             Current tapered down                    4.00
                                                                     and still delivering +/- 1,3A
                      6.00                                                                                     3.00

                      4.00                                                                                     2.00

                      2.00                                                                                     1.00

                      0.00                                                                                     0.00
                             0.0 0.3 0.7 1.0 1.3 1.7 2.0 2.3 2.7 3.0 3.3 3.7 4.0 4.3 4.7 5.0 5.3 5.7 6.0 6.3
                                                                 Time (H)
 Hawkins Adjustable Chargers
• These chargers include the Pro 15, Pro 30, Pro 615,
  the Pro 224, Pro 324 & Pro 524.

      • All these chargers have operator controlled switches for
        both voltage & current. These allow the operator to
        charge multiple batteries if desired and vary the charging
        current to obtain the best charging profile.
      • They use fuses &/or thermal cut-outs &/or circuit
        breakers for protection.
      • They use toroidal transformers – a very efficient design
      • The last 3 are combination engine starters/battery
        chargers and are able to boost start a vehicle with a flat
Hawkins Pro 15 Operator
Adjustable Taper Charger

                   Current Selector

                     Overload c/b

Voltage Selector
          Pro 15 Charging 50 Ah Exide Battery
      This charger has manually operated switches to
                           control the output current
              16.000                                                                        12



                         Pos’n 3 on current selector                                        8
              10.000      Voltage rising, current                    Current low..
                               tapering down                       Pos’n 4 selected
Voltage (V)

                                                                                                 Current (A)
               8.000                                              Current increases &       6
                                                                     voltage rises



               0.000                                                                        0
                    0.00 0.25 0.50 0.75 1.00 1.25 1.50 1.75 2.00 2.25 2.50 2.75 3.00 3.25
                                                       Time (H)
 Hawkins Regulated Chargers

• These chargers include the Classic 6, the Smart 6,
  the Smart 15, the Auto Pro 5, Auto Pro 10, Auto Pro
  20 & Auto Pro 50.

• They subdivide into 2 types, voltage regulated and
  fully regulated.
• The Smart chargers are voltage regulated only
• The Auto Pro chargers are fully regulated and
  conform to a precise charging profile. They self adjust
  their performance with ambient temperature change.
• They all use fuses &/or thermal cut-outs for protection
Hawkins Smart 6
Voltage Regulated Automatic Battery

                                3 indicator lights
                                Red – Power on
                               Yellow – Charging
                                Green - Charged
          Smart 6 charging Exide 628 50 Ah Battery
       This automatic charger is voltage regulated
                                 Voltage decays to bottom limit
     Voltage reaches top limit &
                                     & charger switches on.
charger switches off. Current falls                            Current & voltage rise
                                                           to top limit and cycle repeats.
              15.00                                                                      6.00

  Voltage V

                                                                                                Current A
              13.00                                                                      3.00


              11.00                                                                      0.00
                      0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0
                                                  Time (Hrs)
        Hawkins Smart 15 12-24V
Fully automatic 3 - Stage Charger

                          3 indicator lights
                          Red – Power on
                         Yellow – Charging
                          Green - Charged

                           12/24V Selector
Smart 15 12/24V fully automatic 3 Stage
charger charging 1 x 12v 105 Ah Battery
   Smart 15 12/24V charging 1 x 12V 105Ah battery

                   14.00                                                                                              14.00

                   12.00                                                                                              12.00
                                               Bulk                         Absorption
                                                Charge                       Charge =
                                                                               Charge =             Float
                                                                               1/3 Bulk
                   10.00                                                     1/3 Bulk
                                                                               Charge              Charge             10.00


                                                                                                                              Current (A)
     Voltage (V)

                    8.00                                                                                              8.00

                    6.00                                                                                              6.00

                    4.00                                                                                              4.00


                    2.00                                                                                              2.00

                    0.00                                                                                               0.00
                        0.00   0.50        1.00     1.50   2.00      2.50       3.00        3.50          4.00     4.50
                                                              Time (H)
          Sealed, Maintenance Free

• There is an accelerating trend to sealed,
  maintenance free batteries particularly in
  hard-to-service applications.
• Such batteries demand an automatic charger.
• The more intelligent the charger, the better
  the result.
• Time constraints for charging dictate the
  rating of the charger and thus the turn round
  time of the battery.
         Common Battery Charger
• A damaged or sulphated battery will result in little
  or no current flow. The customer then complains that
  the charger does not work. Check this by connecting
  the charger to a known good battery.
• An automatic charger needs a minimum voltage in
  the battery of about 10v before it will switch on. An
  extremely flat battery may not allow this to occur.
• Customers short out the clamps to see if the charger
  is working. This will result in blown cable fuses or
• Badly corroded clamps mean a poor connection
  between charger and battery. Poor maintenance of
  clamps can mean no current flow and/or heating at
  the point of contact i.e. the battery terminal.
               Typical Battery Charger

• Home Use – Unsophisticated customer
  generally topping up batteries – suggest
  Smart 6, Smart 15.
• Leisure/Recreation – Biking, Boating,
  Fishing, Golfing, Caravanning. Wants
  battery always ready to go. Suggest Smart
  15, Auto Pro 10,Auto Pro 20.
 Hawkins Manufacturing (Pty) Ltd

• Thank you for watching this Presentation.
• If you have any queries or comments please
  contact us
• via our website
            or email

• or telephone/fax   031 579 2813 (Tel)
                     031 579 4642 (Fax)

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