I tried 2 different batteries.
Ctek d250s solar panel size.
If you ve bought a panel with that high a voltage to use with the ctek you re out of luck.
I ve had a ctek d250s in my hilux canopy for a few years.
I wanted to know what the input limit was on the redarc.
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.
3 i got from a previous question i asked that the maximum input on the solar side for the ctek was 25a.
Alternator is a standard non electronic type.
Do not use with panels connected in series.
Most panels seems to have an output above 30v.
As stated max permitted is 21 22v.
I put a volt meter to solar panel and it puts out 22 volts open circuit.
If you do use the ctek d250 with panels that have built in solar regulators it will still charge but not as efficiently.
It seems to be able to both step up and step down the voltage from both sources to do the 5 stage charging.
I assume they are more suited to a house solar system rather than a 4x4 camping setup.
Total power rating of the solar panel.
It has been working fine.
Service battery can be agm or flooded type as per user manual.
It is a temperature compensated 5 stage charger battery isolator and mppt controller.
I added a 250w solar panel today connected it to the d250s to charge while i m not driving.
It charges my two 100ah agm batteries for my fridges and lighting via the alternator.
You can also assist the power you get from your ctek d250 by adding a ctek smartpass to your system.
I have a 250w panel which is under the max voltage at open circuit.
I cannot keep the battery charged with the alternator and solar panel.
Minimum solar panel is 40w and a maximum 500w.
And the 5 stage charging can get its power from a solar panel or the alternator.
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.
Standard wiring for ctek d250s dual.
If using multiple panels connect in parallel and ensure open circuit voltage is less than 23v dc.
No external regulator is to be fitted on solar panel.
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.
Just wanted to confirm difference and maybe this justifies the price difference.
If i attach 3 100w solar panels at 12v or 13v im ok on the ctek at about 25 or 23 amps.
Ctek 250s dual specs and yeah i don t see any solar specs either.