Battery Tender 800 Weatherproof Charger - Submersible 12V Trickle

Our review of the Battery Tender 800 Weatherproof Charger finds it ideal for riders, boat owners and anyone who keeps vehicles in wet or harsh environments; the single biggest reason to buy is its true waterproof design that allows the unit to keep a 12 volt lead acid battery at 100 percent state of charge even when exposed to water. This reviewer appreciated that it offers a low.800 ampere recharge rate intended for long-term maintenance rather than rapid recovery, and that it can be mounted on or in a vehicle so you can plug it in and forget it until the machine is needed.

Key Features

• Fully waterproof: The charger is designed to keep working when exposed to moisture and can actually operate while submerged, which is crucial for marine or exposed outdoor use.
• 12 V,.800 A output: The low-rate recharge gently brings lead acid batteries to full charge and is safe for long-term maintenance without overcharging.
• Maintains 100 percent charge: When left plugged into a household AC outlet, it holds the battery at full state of charge indefinitely so batteries are ready when needed.
• Easy installation: The unit can be mounted on or inside the vehicle, making it convenient to wire in and leave permanently connected.
• Vibration resistant: Built to tolerate vibration so it survives motorcycle, powersports and marine environments where movement is constant.

Who It's For

The Battery Tender 800 is best for motorcycle owners, small-boat operators, snowmobile or ATV users, and classic-car stewards who need a reliable trickle charger that survives wet and vibrating environments. Its waterproof construction and gentle.800 ampere charge rate make it especially suited to batteries that spend long periods idle but must remain ready.

It is not aimed at users who need rapid jump-starting or high amperage recovery; those who require fast charging or frequent deep-cycle replenishment should look at higher-amp chargers or dedicated jump starters instead. Also, it is intended for lead acid battery chemistries rather than specialized lithium systems unless the battery maker explicitly supports a 0.8 A float.

Pros & Cons

Pros

• True waterproof design allows the charger to operate in wet conditions and even submerged.
• Maintains batteries at 100 percent without overcharging, prolonging battery life by 2-4 times.
• Compact mounting options and vibration resistance make it practical for vehicles and boats.

Cons

• At.800 ampere output it charges slowly and is not suitable for quick recovery from a deeply discharged battery.
• Designed for lead acid batteries; users with lithium packs should verify compatibility before use.

Specifications

Our Verdict

The Battery Tender 800 Weatherproof Charger is a practical, value-minded choice for anyone who needs reliable, long-term maintenance of lead acid batteries in wet or mobile environments. Its true waterproofing, vibration resistance and ability to maintain 100 percent charge make it worth buying for boats, motorcycles and stored vehicles, provided you accept the tradeoff of a slow.800 ampere recharge rate.

Frequently Asked Questions

Can this charger be left connected year-round?
Yes. It is designed to maintain a battery at full charge indefinitely when connected to AC power.

Is it safe for marine use?
Yes. The unit is fully waterproof and can operate while submerged, making it suitable for marine applications.

Will it quickly recharge a dead battery?
No. The.800 ampere output is intended for trickle charging and maintenance, not fast recovery of deeply discharged batteries.