Battery Tender is a brand of products for maintaining a car battery's charge, generically known as trickle chargers. A trickle charger delivers a slow and steady energy stream to maintain a car battery's charge during storage. Maintaining a charge helps prevent damage caused by depleting a car battery.

To be safe, assume that the batteries require a full 100% charge after the cells are filled. For example, a 16 Ah battery will take about 13 hours to get to the absorption voltage (constant 14.4 Volts). It may take another 6 to 8 hours to reach the float voltage (constant 13.2 Volts).

In my experience, trickle chargers have been small low - limited current (1 or 2 amps) unregulated power supplies, whereas battery tenders are related to the more modern Smart Chargers in that they contain sensing circuitry with controls to maintain the battery at its optimum charge.

Proper use of a Battery Tender should not damage a battery's lifespan if used appropriately. Using it correctly can extend its lifespan by helping keep its charge steady and avoiding overcharging or undercharging issues. However, it does not match the type of battery being charged properly or is misused.

If you try to charge a dead battery having a voltage below 3 Volts, the Battery Tender® Junior charger will not start. An internal safety circuit prevents the charger from generating any output voltage unless it senses at least 3 Volts at the charger output.

So you just pull those two apart and it comes with two different setups. One of these you can wire. Into your battery terminal posts. So you just take that off and these are looped.

Unlike standard and trickle chargers, a battery maintainer can be attached to a battery indefinitely without any fear of overcharging.

Most all Automatic maintainers are designed to be connected to a battery and in theory you could walk away forever! While the battery wont last forever on a battery maintainer as the activate material inside the battery will eventually break down and cause a failure.

If you try to charge a dead battery having a voltage below 3 Volts, the Battery Tender® Junior charger will not start. An internal safety circuit prevents the charger from generating any output voltage unless it senses at least 3 Volts at the charger output.

Grid stability: Smart chargers can help to stabilise the grid by providing accurate information on demand and managing the charging process to avoid peak demand periods. This will reduce the need for expensive grid upgrades and improve the overall efficiency of the electricity system - so everyone benefits.

If you try to charge a dead battery having a voltage below 3 Volts, the Battery Tender® Junior charger will not start. An internal safety circuit prevents the charger from generating any output voltage unless it senses at least 3 Volts at the charger output.

Most all Automatic maintainers are designed to be connected to a battery and in theory you could walk away forever! While the battery wont last forever on a battery maintainer as the activate material inside the battery will eventually break down and cause a failure.