As mentioned in a previous question, I am looking to hardwire a battery charger/tender in my car, so I can just plug it into mains voltage when the battery is drained, or the car is sitting outside in a cold climate.
- Must be able to charge a near-flat battery sufficiently to start the engine, in a reasonable amout of time (as a reference, 1–2 hours on the €20 charger I have is usually sufficient)
- Must be suitable for leaving plugged into mains voltage permanently (i.e. not cause damage to the battery, such as by overcharging, or drain it when finished charging)
- Must detect the condition of the battery, and switch between charging and maintenance mode as needed (no manual switching between modes – plug in when coming home, unplug before driving off, and otherwise no need to worry about it)
- Must be suitable for being connected to the vehicle’s circuit permanently, whether plugged in or not
I am planning to mount this near the fuse panel, i.e. inside the passenger compartment where I have access to 12V terminals suitable for the load (presumably no more than around 15A), and just run the cable to the bumper. Therefore, the device does not need to be waterproof.
Question: what features should I look for when buying a charger not specifically designed to be hardwired? Can I use any charger as long as it has some visual display of the charge state (charging vs. done), indicating it “knows” when to switch off? Or do I need to look for anything more specific in the product descriptions – and if so, what (short of the words “suitable for hardwiring”)?
I am in a non-English-speaking market, thus just asking for a “battery tender” in a shop will not work. Also, I don’t need a premium brand. Hence language-neutral and brand-neutral answers will be appreciated.