Ctek D250s Solar Panel Size

I tried 2 different batteries.

Ctek d250s solar panel size. I have a 250w panel which is under the max voltage at open circuit. It charges my two 100ah agm batteries for my fridges and lighting via the alternator. Warning when using with solar panels the panel open circuit voltage must not exceed 23v dc or the ctek unit may be damaged and the warranty voided. Minimum solar panel is 40w and a maximum 500w.

Just wanted to confirm difference and maybe this justifies the price difference. Alternator is a standard non electronic type. I want to add solar panels but the manual that comes with unit is silent on the question of what solar input it is able to handle so i queried it with ctek sweden and the following reply has come back from them. If using multiple panels connect in parallel and ensure open circuit voltage is less than 23v dc.

Standard wiring for ctek d250s dual. I currently run my ctek d250s connected to two 100ah lead crystal batteries. I connected the ctek d250s to the solar panel for 3 days in full sun and it could not charge the battery over 12 4 volts. If you ve bought a panel with that high a voltage to use with the ctek you re out of luck.

Most panels seems to have an output above 30v. I put a volt meter to solar panel and it puts out 22 volts open circuit. I added a 250w solar panel today connected it to the d250s to charge while i m not driving. No external regulator is to be fitted on solar panel.

3 i got from a previous question i asked that the maximum input on the solar side for the ctek was 25a. Do not use with panels connected in series. You can also assist the power you get from your ctek d250 by adding a ctek smartpass to your system. The ctek d250 has a built in solar regulator so the panels you use do not need additional regulators.

And the 5 stage charging can get its power from a solar panel or the alternator. I cannot keep the battery charged with the alternator and solar panel. If you do use the ctek d250 with panels that have built in solar regulators it will still charge but not as efficiently. If i attach 3 100w solar panels at 12v or 13v im ok on the ctek at about 25 or 23 amps.

It has been working fine. Total power rating of the solar panel. As stated max permitted is 21 22v. I assume they are more suited to a house solar system rather than a 4x4 camping setup.

Open circuit voltage of solar panel in full sun is 22 volts dc max. I ve had a ctek d250s in my hilux canopy for a few years. It is a temperature compensated 5 stage charger battery isolator and mppt controller. It seems to be able to both step up and step down the voltage from both sources to do the 5 stage charging.