Questions about Ctek D250SE Lithium DC/DC Converter 12V

The CTEK D250SE battery charger can draw power from several sources without a mains connection: - Alternator: it can draw power directly from the vehicle's alternator, including vehicles with smart alternators. - Solar panel: It has a built-in MPPT solar controller that allows it to draw power from a solar panel. - Wind generator: It can also draw power from a wind generator when connected to the solar input. These multiple energy sources make the device particularly flexible for use in vehicles without access to mains power.

I think you should read what the part is actually for....

The CTEK D250SE battery charger is designed to maintain and service batteries over an extended period of time, even during the winter. - The device has a low back current drain of less than 1 Ah per month, which means that it draws very little energy from the battery when it is not connected to the main power supply. - It has a maintenance charging function that ensures the battery is kept at an optimum state of charge by sending regular 3-second pulses to the battery. - The device can also divert the charge from the car battery to the starter battery when the car battery is fully charged to ensure that both batteries remain in good condition. Through these functions, the CTEK D250SE can effectively maintain a car battery over the winter and ensure it is ready when it is needed again.

Yes, that's right! I use the device on my boat and am very satisfied!

It seems to be possible to connect the D250SE directly to a solar panel. If we refer to the manufacturer's documentation; "...the D250SE charges the battery from either an alternator, a solar panel or a combination of both..."

According to the instructions, the "trickle charge" charges the starter battery with the help of the solar system when the supply battery is full. If the ignition was switched on overnight, the trickle charge will not help because the sun does not shine at night and the solar system cannot charge the starter battery. By the way, in modern cars or camper vans, amperes flow when the ignition is switched on (via about a dozen control units, radio, daytime running lights, navigation system, etc.). This means that a starter battery will run down in a few hours or at least no longer be able to start the engine.

It is better, cheaper and can charge Lifepo batteries.

Adjustment options for AGM 14.7V and wet Pb 14.4V end-of-charge voltage available. Check out ctek.de.

I have already installed some Ctek dual regulators. These are awesome. I wonder if 200Ah LiFePO4 is needed or if 100Ah is enough. For 200Ah you have a maximum of 2*20A charging current available. So a complete charge takes over 5h. I once installed a 230Ah AGM with a Ctek Smartgenerator. up to 140A go through it. You have to find out whether your LiFePO4 can handle this. In many cases a charging current of more than 50A is not suitable. Please note the cable cross-sections for high currents!