Some garages hold one vehicle. Most hold a mix — a modern daily driver alongside a vintage motorcycle, a classic pickup next to a current-model ATV, a pre-war tractor that shares a shed with modern equipment. The Battery Tender® Plus 6V/12V 1.25A is designed for that garage: a single intelligent battery charger and maintainer with a manual voltage selector that covers both legacy 6V and standard 12V lead-acid systems with the same ISM (Infinite Sequential Monitoring™) precision Battery Tender® has delivered since 1965.

One Unit. Both Voltage Classes.

A manual 6V/12V selector switch allows precise matching of charge voltage to the specific battery being maintained. Select 6V for vintage vehicles and pre-1960s equipment; select 12V for modern motorcycles, ATVs, cars, trucks, and powersports vehicles. At 1.25 Amp, the Plus 6V/12V handles lead-acid batteries from 14Ah to 80Ah at either voltage setting, with ISM delivering the correct 4-stage charging profile for each chemistry.

ISM: 4-Stage Charging at Either Voltage

• Initialization — Battery health check and polarity confirmation before current flows
• Bulk Charge — Full 1.25 Amp output at the selected voltage restores depleted capacity efficiently
• Absorption — Current automatically tapers as the battery approaches full charge, preventing overcharging
• Float Maintenance — Precisely regulated micro-current maintains peak voltage at 6V or 12V indefinitely, 24/7, without overcharging

Compatible: 14Ah to 80Ah. All lead-acid chemistries at either voltage: flooded, AGM, gel cell, and sealed maintenance-free.

6V Applications

• Vintage and pre-1960s motorcycles
• Classic and antique automobiles
• Antique tractors and farm equipment
• Pre-war and transitional-era military vehicles
• Vintage scooters and mopeds
• Classic outboard motors with 6V starting systems

12V Applications

• Motorcycles and touring bikes
• ATVs, UTVs, and side-by-sides
• Cars, trucks, and SUVs up to 80Ah
• Boats and personal watercraft
• Snowmobiles and lawnmowers
• Classic vehicles with converted 12V systems
• RVs and seasonal vehicles

The Mixed-Voltage Garage

Owning both vintage and modern vehicles typically means owning two incompatible chargers — a 6V unit for the classics and a 12V unit for everything else. The Battery Tender® Plus 6V/12V eliminates the duplication entirely. One unit charges the pre-war automobile in October and the modern powersports vehicle in November. One purchase, one cord to manage. For restoration shops, multi-vehicle collectors, and mixed fleets, the efficiency compounds across every bay in the facility.

Voltage Selection: What You Need to Know

Always verify battery voltage before connecting. A 6V setting applied to a 12V battery will undercharge it chronically; a 12V setting applied to a 6V battery will overcharge and may damage it. The manual selector is deliberately physical — there is no automatic voltage detection. Confirm the battery voltage, set the switch, and connect. ISM handles everything from that point forward.

Automatic Temperature Compensation

At both voltage settings, charge voltage adjusts automatically based on ambient temperature — increasing in cold conditions to ensure a complete charge, reducing in heat to prevent overcharging and gassing. Correct voltage delivered in any storage environment, any season, without manual adjustment.

Safety Features

• Spark-proof connection — No current flows until polarity and connection are confirmed correct, protecting sensitive electronics at either voltage
• Reverse polarity protection — Automatic shutdown if clamps are reversed
• Short-circuit protection — Automatic fault detection and shutdown
• ETL and CETL certified

Sulfation Does Not Discriminate by Voltage

A 6V battery left discharged through a winter accumulates sulfation just as destructively as a 12V battery. Sulfation — the permanent, irreversible hardening of lead sulfate on battery plates — is the leading cause of premature battery failure across all lead-acid chemistries. The Battery Tender® Plus 6V/12V prevents sulfation at either voltage through continuous float maintenance, extending battery life from 2–3 years to 5 years or more across your entire fleet, vintage and modern alike.

Limited Warranty | DeLand, Florida Since 1965