C Tek D250S Dual Solar Pulsing

I am waiting for mine to arrive so can't comment on actual operation.
I have read that they have a bit of trouble with panels UNDER about 100 watts if flat mounted, but if tilted to track the sun can handle lower watts.

Nope - it is the other way round

It struggles with anything LESS than 80-100W

CJ

Sorry - that was Nope to Corrugate which means I agree with Rod N

Hi corrugate 75 my panels were 180 watts combined

Meant to mention I tried it with 1 panel 90 watts and it was the same

Thanks for the reply. my panesl dont have a regulator. When you are on solar does the alternator light come on or just the solar and battery lights ? My alternator light was comming on with the solar when the motor was not running. I decided to disconnect the alternator input, must have touch something with the wire as the D250S is now lifeless.
Have you connected your solar directly to the 250S dual or via a fuse ? Did you run your earth directly to the battery or to the earth on the 250S dual ?
Thanks Peter

Hi Peter,

The solar panels plug directly into the solar port on the D250S, then via a 30A fuse to the batteries. I have an Anderson connector mounted on the camper and wired to the Ctek controller. I made up a second lead from the solar panel, bypassing the onboard regulator, which also has an Anderson connector on the end to connect to the camper's connector.
I have left the original lead on the solar panel which has a Merit plug which I can use to connect to my Thumper portable battery pack when I'm using that with a tent.

The D250S can accept input from both the alternator and solar panels (if they are permanently mounted) and the controller will determine the best input for it to use.
However, the alternator light should only coome on when there is voltage from the vehicle alternator, so it sounds like you have a wiring problem if it is illuminated when only solar panel input is applied.
If you disconnected the alternator input and it was live, something is very amiss.
I assume the engine wasn't running at the time?

It is also good practise to have fuse protection between the alternator circuit and the input to the Ctek to protect against shorts such as you experienced.

It kind of sounds to me as if your alternator feed may be via the primary battery without a dual battery controller in the circuit. This would result in full battery voltage being present all the time, rather than only when the engine is running and the battery controller has detected a full primary batttery voltage and thus energised the secondary circuit to your camper.

The negative (earth) wire connected to the D250S runs back to the negative terminal on the vehicle's auxiliary battery via heavy duty twin core cable and also to the negative terminal on the camper batteries. An isolator between the primary (starting) battery and the auxiliary battery keeps the two batteries electrically isolated from each other while allowing the alternator to charge both.

Never rely on body or chassis earthing only. A full earth circuit should run from the source battery (be it the starter, or auxiliary) to any remote ones and include any dc-dc charger in the circuit.

Derek Bester from Sidewinder has some excellent advice on remote batteries, etc.
These are available on his web site and also under the Articles heading on the top of the ExplorOz page.

Battery Article Link
Caravan Battery Charging

Good luck!

My D250S experience FWIW.

I have a D250S Dual charger which is normally connected to the (main battery) alternator and a 90 watt panel. When I have the vehicle parked at home in the driveway I switch the solar input across to the output of a 13.8 volt 25amp DC power supply (built into the vehicle).

As I have Victron Battery monitor installed I can observe the amount of current flow to & from the battery and have noticed the same 'pulsing' effect (that has been described above) when 1st connected to the 23amp power supply.

After a short time (approx 3 min) the current flow settles down to a more continuous (non-pulsing) flow.
I'm guessing that initially the charger applies some charge to the battery and then does some checking. This goes on for a short time while it monitors the battery's progress before applying a continuous charge. I've watched the battery monitor display as the charge drops down to under an amp.

My panel can easily supply well over 5 amps (in good sun) and the wattmeter I have connected in series with panel advises a 'healthy' input to the ctek when the sun is plentiful.

Hi Arjay, thanks for your response. When you are on solar without the car engine running does the alternator light come on with the solar and battery light or do you just have thge solar and battery lights on, that is the alternator light never glows when you are on solar alone.
Mine was cycling solar alternator solar alternator and battery and then cut out and repeat the cycle.
Cheers Peter

Peter,

Alternator Light (while using only solar charging):

My alternator light will come on but only after the 2nd battery is fully charged. This indicates that the Main battery (engine starter) is now being charged by the solar panel, i.e. you now have 3 lights ON, [1Green & 2 Amber lights, Solar panel & Alternator].
The indicator lights explanation is shown on page 4 of the manual.


Alternator feed to Ctek:

FWIW my ctek 'alternator' connection is via the +ve terminal of the starter battery, without any voltage-sensing disconnect hardware in between.
The ctek charger has the 'smarts' to manage this.........from page 12 of the manual-> "CHARGING PROGRAM D250S DUAL
The charger starts charging the target battery when the supply voltage exceeds 13.1V for 5 sec (engine on).
The charger stops charging the target battery when the supply voltage drops below 12.8V for 10 sec (engine off)."


Pulsing O/P from ctek:

The picture (see below) found on page 12 of the ctek manual and shows the various charging phases and may help to explain the pulsing behaviour that is often mentioned.
(The 1st charging step is desulphation with pulsing voltage & current.)



The manual may downloaded from:
http://ctek.com/Archive/ProductManualPdf/D250S%20DUAL_EN.pdf

regards,
Rob