The Battery Tender 800 is a weatherproof, shock-resistant, and vibration-resistant battery charger and maintainer. At just 4.4-by-2.15-by-2.9 inches and weighing just one pound, it’s about the size of a computer mouse, making it easy to tuck away in tight spaces. The interior is sealed with an epoxy resin, ensuring it can handle the rigors of outdoor use, whether it’s mounted under a motorcycle seat or left out in the rain.
The weatherproofing is a game-changer if you leave your bike outside in the elements. Battery Tender’s three-year warranty confirms its confidence in the 800’s weatherproof rating.
The unit comes with a 12-foot output cord, a fused ring terminal harness, alligator clips, and an SAE connector, offering flexibility for both permanent and temporary connections. The Battery Tender 800 is compatible with lead-acid batteries (AGM, flooded, and gel cell) and lithium (LiFePO4) batteries, with a Select button to toggle between the two.
The Battery Tender 800 is more than a trickle charger; it is an intelligent charging system. Equipped with an ISM (Integrated Smart Microcontroller), it delivers a three-step charging process—initialization, bulk charge, and float mode. Once the battery is fully charged, it automatically switches to float mode to maintain an optimal voltage without overcharging.
Its 800mA output (0.8 amps) means the device is not designed to charge a completely dead battery. If your battery is fully depleted, you’ll need a higher-output charger to get it started before relying on the Battery Tender 800 for maintenance.
Despite that, the Battery Tender 800 brought a four-year-old battery I had purposely completely depleted back to full charge in a matter of hours and maintained it flawlessly.
The 800 is set and forget—exactly what you want in a battery maintainer. You can connect it using the alligator clips for a temporary setup or the ring terminals screwed to your battery for a semi-permanent installation. However, the ring terminals are attached to the alligator clips. So, if you choose the ring terminals, you lose the ability to quickly move the Tender to another battery.
The pigtail you hide under the seat or inside body plastic has an inline 7.5-amp fuse that terminates in the SAE connector you plug the Battery Tender 800 into. The SAE connector is also a convenient place to power a portable air compressor, though most will blow a 7.5-amp fuse, as will two 90-watt heated jackets.
The LED indicators are simple yet effective. A flashing red light signals that the battery isn’t charging, and a solid red indicates charging in progress. A flashing green shows the battery is at least 80 percent charged, and a solid green confirms the Battery Tender 800 is in maintenance mode.
The Ultimate Motorcycling Yamaha Ténéré 700 Project Bike suffers from significant parasitic power drain. The Sizzapp tracker, Thunderbox power distributor, Garmin Zūmo XT2 GPS, and Blueskysea dash cam all draw power, even when the bike is off. For $60 MSRP, the Battery Tender 800 gives me peace of mind, knowing that my battery will be ready for that O-dark-30 start.
