OptiMate Battery Charger - Information & FAQs
Safety & Desulfation
Could high voltage desulfation mode harm vehicle electronics?
Answer: No, it cannot.
The OptiMate's high voltage desulfation mode cannot engage if vehicle electronics or wiring are 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.
IMPORTANT: To effectively desulfate a battery, it must be disconnected from the vehicle wiring before connecting to the OptiMate.
Battery Recovery & Sulfation
Should a sulfated battery be replaced?
Answer: No, not necessarily!
Batteries develop a high resistance to charging which the average smart charger cannot overcome. The OptiMate has a unique ability to desulfate and permanently recover batteries that have been neglected or deeply discharged.
How OptiMate's desulfation works:
- Applies a voltage of up to 20V at controlled low current for a maximum of 2 hours
- Recovers the battery so it can accept a charge using normal charging algorithms
- Continues with a unique charge & check stage to remove remaining sulfate crystals
- Performs a charge retention test to confirm adequate recovery
- Engages long-term maintenance mode
Important considerations:
- Not every 'dead' battery can be desulfated
- A desulfated battery may not recover to 100% of its previous ability
- Recovery effectiveness depends on how soon after discharge the battery is treated
- Heat is a major killer of lead-acid batteries
- Batteries discharged in freezing temperatures (below 32°F/0°C) may suffer physical damage
- High temperatures (above 95°F/35°C) cause water evaporation and reduce recovery chances
Will the vehicle's charging system recharge a deeply discharged battery?
Answer: Not effectively.
A vehicle's charging system is designed to supply power at a voltage not exceeding 14.5V. This will not deliver sufficient charge to effectively reverse sulfation in a deeply discharged battery that has developed high resistance. The battery will continue to present starting problems, and sulfation will spread if left unchecked.
New Battery Preparation
Do new batteries need a special first charge?
Answer: Yes, absolutely!
Without proper preparation, a battery will only ever deliver 70-80% of its capacity and experience a short service life.
Proper new battery preparation:
- Fill with clean battery acid of the correct density
- Let stand for at least 30 minutes (longer for larger batteries)
- Fully charge to the recommended voltage
The initial activation determines how well and how long the battery will perform.
Do factory-filled batteries need charging?
Answer: Yes, they do.
ALL batteries self-discharge, especially in adverse temperature conditions (below 32°F/0°C or above 95°F/35°C). As batteries discharge, lead sulfate is created, which forms crystals that attach to the plates and cause further discharge. Stored batteries should be maintained at full charge or periodically recharged to remain 100% effective.
Charging & Maintenance
Does a larger battery require a higher current charger?
Answer: No.
To maintain a battery without causing damage or loss of electrolyte, voltage is the critical factor, not current. Once fully charged, a battery requires only a few milliamps to overcome its own resistance. Connected devices may add to the current draw, but it should remain in the low milliamp range.
Are all maintenance chargers the same?
Answer: No, they are not.
Most smart chargers set their maintenance voltage at 13.2V, which is appropriate for filler cap batteries but insufficient for sealed AGM/VRLA (including MF type) batteries. Sealed batteries require maintenance voltages of 13.5V minimum to remain at 100%. Undercharging eventually results in a discharged battery and sulfation.
OptiMate advantages:
- Maintenance voltage set at 13.6V for all battery types
- Limited duty cycle (30 minutes on, 30 minutes off) reduces water loss in filler cap batteries
- Monitors for parasitic loads and warns with WEAK LED if battery drops below 12.3V
- Continues to recharge and maintain the battery even with parasitic loads
Should a fully charged battery wait to be recharged until voltage drops?
Answer: No.
Lead-acid batteries last longest if maintained at the fully charged level, especially when not in use. Allowing batteries to cycle between discharged and fully charged reduces overall battery life.
The OptiMate 4 provides up to 1A at 13.6V for 30 minutes in maintenance mode, then checks whether the battery can maintain its charge. This cycle ensures that current drawn by alarms, computers, or parasitic losses will never cause a good battery to drop below 95% of full charge.
Storage & Usage
Can the OptiMate be left permanently connected during storage?
Answer: Yes, it is recommended.
Storage guidelines:
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Room temperature: All batteries can be left permanently connected
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High temperature (above 86°F/30°C): Can be left connected or recharged weekly; check electrolyte levels regularly
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Below 86°F/30°C: All batteries can be left connected; periodically check and top up filler cap batteries with distilled water
Troubleshooting
The OptiMate did not recharge my deeply discharged battery. What should I do?
Solution: The battery must be removed from the vehicle or disconnected from the vehicle circuitry. The OptiMate's high voltage desulfation mode can only engage if no vehicle circuitry or connected devices are detected.
Only the green POWER LED remains on when charging a deeply discharged battery
Explanation: The OptiMate 4 assesses recoverability by measuring initial battery voltage. If it is not at 0.5V or above, it will not start charging. Such batteries have a very limited chance of being successfully recovered.
TIP: Make sure the battery is disconnected and removed from the vehicle to ensure there is absolutely no current being drawn from the battery.
