information comes from Yamaha and pertains to Yamaha snowmobiles.)
Myth No. 1: The OptiMate’s high voltage desulfation mode can
damage vehicle electronics if connected to an installed battery.
Fact No. 1: The OptiMate’s high voltage desulfation mode
cannot engage if vehicle electronics/wiring is sensed.
Upon connection to a battery the desulfation mode can only
engage if no current enters the battery at a charge voltage of up to 14v. A sulfated
battery’s voltage will initially be typically in the 2 to 6v range. Vehicle
electronics require a higher voltage than this to function so if a battery in
this condition is still connected to the vehicle no electronics can be active.
Even a LCD display circuit will draw a few milli-amperes if a voltage is
applied and upon sensing this, the OptiMate will engage its normal charge mode
with maximum charge voltage 14, 3v.
Important: to effectively desulfate a battery it must be
disconnected from the vehicle wiring before connecting to the OptiMate.
Myth No. 2: Once sulfated, a battery is useless and should
Fact No. 2: This is not always true.
Batteries develop a high resistance to charging which the
average (so-called) smart charger cannot overcome. Usually one is told that the
battery has died and needs replacing and that is how this myth is kept alive.
Over-discharged (i.e. sulfated) VRLA/(including MF type)
sealed batteries often develop internal resistance too high to overcome at
normal charge voltages which requires an initial high voltage charge rate (up
to 25v), under supervised conditions, to reverse the high internal resistance
caused by sulfation on the plates.
The OptiMate’s unique automatic desulfation mode works like
this: Once the OptiMate determines that the battery is sulfated it applies a
voltage of up to about 20v at a controlled low current for a maximum period of two
hours, to recover the battery to the extent that it can again accept a charge
using the more normal charging algorithm. As part of this, the recovery
continues with the subsequent unique charge and check stage which removes
remaining sulfate crystals from the plates. The charge retention test which
follows this stage confirms whether the battery has been adequately recovered
before the long term maintenance “floating charge mode cycle” engages.
The OptiMate battery charger has a unique ability to
desulfate and permanently recover batteries that have been neglected or deeply
However, not every dead battery can be desulfated and
neither can a desulfated battery be recovered to 100 percent of its previous
When a battery becomes sulfated it will suffer some
damage/wear to the plates. The extent of the damage depends on how deeply the
battery was discharged, how long it was left like that and in which average
Heat is a big killer of lead-acid batteries. When a battery
is discharged the electrolyte changes from a sulphuric acid state to lead
sulfate and water. Whereas normal battery acid freezes at well below freezing
point of water, the water which results from a discharged battery freezes at
temperatures below 32 degrees F/0 degrees C and expands, resulting in bent and
buckled plates or at worst, a cracked casing.
At temperatures exceeding 95 degrees F/35 degrees C, water
will evaporate and the more water which evaporates, the higher the
concentration of lead sulfate and the lower the chance of effective recovery.
So, the degree of effectiveness of the recovery depends on
how soon after the battery became sulphated that it is desulfated and
recharged. Even so, we have received letters from a number of OptiMate users
testifying to effective recovery of batteries left discharged (and believed to
be dead) for as long as two years.
Myth No. 3: The vehicle’s charging system will recharge a
deeply discharged battery.
Fact No. 3: A vehicle’s charging system has been designed to
supply power to the electrical system at a voltage not exceeding 14,5VDC. The
voltage is the set parameter and does not necessarily imply any current, as
this depends on the resistance of the battery. The vehicle’s charging system
will therefore not deliver sufficient charge to effectively reverse sulfation
in a deeply discharged battery that has developed high resistance due to a
degree of sulfation. This means that the battery is always going to present
starting problems, usually at the most inconvenient times. Sulfation is like a
virus, if left unchecked, it spreads, so a battery left in this state is
destined to live a short life.
Myth No. 4: Just add the acid to a new battery and it is
ready to go.
Fact No. 4: Sure, if you want a battery that will only ever
deliver 70 to 80 percent of its capacity and experience a short service life.
Batteries that have not been properly prepared before
installation on a vehicle typically fail early, often just after the warranty
has expired, or result in vehicle starting problems just when you are nowhere
Before being installed in the vehicle a new battery should
be filled with clean battery acid (dilute sulphuric acid of the correct density
for the battery—battery acid for “MF” sealed motorcycle batteries has a higher
density than standard battery acid), and left to stand for at least 30 minutes
(the larger the battery the longer it should stand) and then fully charged to
the recommended voltage. The initial activation of the battery determines how
well and how long it will continue to perform.
Myth No. 5: Factory filled and charged batteries need no
charging and are always good to go.
Fact No. 5: All batteries self discharge, faster in adverse
temperature conditions (below 32 degrees F/0 degrees C, above 95 degrees F/35
degrees C) and the more the battery discharges the more lead sulfate is
created. If this is left to float freely in the electrolyte, crystals are
formed that attach to the plates, causing further discharge which in turns
creates more lead sulfate.
Note: Fact is, stored batteries should be maintained at full
charge or at least periodically recharged to remain 100 percent effective.
Myth No. 6: The larger the battery the higher the current
rating the charger has to be, otherwise it will not maintain the battery.
Fact No. 6: To maintain a battery without causing damage or
loss of electrolyte, voltage is the critical factor, not current. Once the
battery is fully charged it requires a few milli-amps to overcome its own
resistance (which causes self-discharge). Connected devices such as an alarm,
trip computer, etc., may add to the current draw, but it should still remain in
the low milli-amp range.
Myth No. 7: Any “maintenance” charger will do; they all
maintain batteries just as well as the next.
Fact No. 7: There are a number of smart chargers on the
market with a controlled maintenance mode which will probably do the job if you
have a filler cap battery (a battery that can be topped up with distilled
However, automatic smart chargers are typically designed not
to overcharge batteries for which the lowest maintenance charge voltage setting
is appropriate, meaning filler cap batteries, which require long term
maintenance voltages of between 13.1 and 13.6v (depending mostly on storage
temperature). This is why most smart chargers have their maintenance voltage
set at 13.2v. However, sealed AGM/VRLA (including MF type) batteries are
undercharged by most smart chargers during long term maintenance. This
eventually results in a discharged battery.
Any chronically undercharged battery will slowly develop
sulfation, resulting in a shorter service life.
The OptiMate is specifically designed to provide good care
for all types of batteries. Its maintenance mode float voltage is set at 13.6v to
adequately maintain modern sealed batteries, but is not excessive for
traditional filler cap types. Furthermore, the OptiMate’s limited duty (30
minute on, 30 minute off) maintenance cycle allows filler cap batteries to cool
during half the time and thereby significantly reduces water loss. During the
30 minute off period, the OptiMate circuit checks for current loss due to
parasitic loads such as alarms, aged wiring, worn contacts, etc. If any such
loss is drawing the battery down below 12.3v, the OptiMate’s WEAK LED will warn
of this while the circuit will continue recharge and maintain the battery.
Myth No. 8: Once a battery is fully charged it should not be
charged again until the voltage drops below a certain level.
Fact No. 8: Lead-acid batteries last longest if maintained
at the fully charged level, especially when not in use. So, the key to how long
it lasts mostly depends on how the battery is treated when it is not used. A
fully charged battery will generally maintain an adequate charge for a month,
if it is not too warm and if no external current draining devices are connected
or if the current draw due to vehicle alarm, computer, etc., is normal.
However, it is recommended that the battery of any vehicle fitted with an
alarm, computer etc., and left to stand for a long period of time should be
supported by a good maintenance charger.
Batteries have a finite life. If a charger allows the
battery to cycle between discharged and fully charged, it reduces the overall
life of the battery. Some smart chargers provide only a very low current (as
low as 10mA) which is often insufficient to cope with parasitic loads (alarms,
aged wiring, flashing light, bike computer) in modern vehicles. Some smart
chargers will only revert from maintenance to high current charging once the
voltage has reduced to below 12.5v, or even 12.2v in some cases. At 12.5v a
sealed AGM/VRLA (including MF type) battery is only at 60 percent charge.
The OptiMate provides up to 600mA at 13.6v for 30 minutes in
maintenance mode, then during the following30 minutes checks whether the
battery can maintain its charge. This period is followed in turn by the next 30
minute period during which charging is again offered to the battery. This cycle
ensured that the current drawn by an alarm, computer and/or the parasitic
current loss through aged wiring will never cause a good battery to drop below
95 percent of full charge.
Q No. 1: Can the OptiMate be left permanently connected to a
battery when the vehicle is stored?
A No. 1: Yes, we recommend it.
However, the environment the vehicle is stored in should be
at room temperature.
In a consistently high temperature environment (above 86
degrees F/30 degrees C) all batteries can either be left permanently connected
to the OptiMate or connected and recharged on a weekly basis. If the OptiMate
is left permanently connected, the level of the electrolyte in filler cap
batteries should be regularly checked and topped up and sealed batteries should
be checked for signs of a loss of electrolyte (these are typically condensation
on the battery or within the vehicle’s battery compartment or a bubbling or
For temperatures below 86 degrees F / 30 degrees C all
batteries can be left connected, but again, the electrolyte level in filler cap
batteries should be periodically checked and topped up with distilled water if
Q No. 2: The battery in a vehicle was deeply discharged, but
the OptiMate did not recharge it. What should I do?
A No. 2: If the battery is deeply discharged, the battery
must be removed from the vehicle, or be disconnected from the vehicle
circuitry. The OptiMate’s high voltage desulfation mode can only engage if no
vehicle circuitry or connected devices are detected by the OptiMate’s circuit.
Q No. 3: A battery is deeply discharged and I tried to
recharge it with the OptiMate, but only the green POWER LED remains on, no
other LEDs light up.
A No. 3: The OptiMate assesses recoverability of the battery
by measuring the initial battery voltage. If it is not a 2v or above, it will
not start charging. Usually such batteries have a very limited chance of being
Tip: Make sure the battery is disconnected and removed
from the vehicle to ensure there is absolutely no current being drawn from the
battery. Sometimes there is a hidden load (example, a small fault in the
vehicle wiring) that keeps the voltage below 2v. Allow the battery to stand for
a few hours to recover some voltage and then reconnect the OptiMate.