CTEK D250S & External Solar Panel with Regulator...

[ROnEM]

We are about to go and remote camp in one place for 8 days, genies not allowed, so I purchased a folding solar panel.

It is 200W with an open circuit voltage of 22.8V, 11.37A. The smaller panels with 22v or less were sold out and no deliveries until after we get back hwell:

As the CTEK D250S Solar Max Voltage is 22v, and on a sunny day the panel will easily reach full open circuit voltage, I will look at putting a couple of Zener Diodes in series on the panel to drop the voltage by 1.4v to be safe...

However, in the meantime, I was wondering how well it will recharge 2 x 100AH GEL batteries if I connect the output form the Solar Panel's regulator to the Anderson Plug connector on the drawbar that is connected to the vehicle alternator terminal on the CTEK? This is the connection that goes to the Tug to normally charge the VAN's batteries.

The Solar Panel's regulator is currently set for Sealed Lead Acid Battery and is outputting 14.4v

I have had to go a folding psolar panel for nowWhile I had the factory pre-wire for solar, I am not going to put panel/s on the roof as it has a sag in the middle and has shifted so much it is wearing small holes in the pop-top skirt and will need to be fixed/replaced.

Cheers,

Rohan

 

[boots33]

It is 200W with an open circuit voltage of 22.8V, 11.37A. The smaller panels with 22v or less were sold out and no deliveries until after we get back hwell:

As the CTEK D250S Solar Max Voltage is 22v, and on a sunny day the panel will easily reach full open circuit voltage, I will look at putting a couple of Zener Diodes in series on the panel to drop the voltage by 1.4v to be safe...

The first thing I would do is send an email to Ctek and see if you can use your panel as is. their contact page is here and you may find they will be ok with the extra .8v. If not then the two diodes in series will do the trick, you should only need to use normal silicon power diodes not zener diodes. Make sure you do not use Schottky power diodes that are normally used with solar panels as these will likely not give you enough voltage drop. also note the diodes will probably get quite warm so keep that in mind when you are placing them.

However, in the meantime, I was wondering how well it will recharge 2 x 100AH GEL batteries if I connect the output form the Solar Panel's regulator to the Anderson Plug connector on the drawbar that is connected to the vehicle alternator terminal on the CTEK? This is the connection that goes to the Tug to normally charge the VAN's batteries.

Ctek are the only ones who could tell you if this would be ok. It is certainly not normal or desirable to run two regulating devices in series with each other. It would probably work to some degree but may produce unexpected results.

The Solar Panel's regulator is currently set for Sealed Lead Acid Battery and is outputting 14.4v

Yep that will be ok.

I have had to go a folding psolar panel for nowWhile I had the factory pre-wire for solar, I am not going to put panel/s on the roof as it has a sag in the middle and has shifted so much it is wearing small holes in the pop-top skirt and will need to be fixed/replaced.

Rohan if you have the solar pre wire then an easy solution may be for the time being to connect your panel to that wiring instead. Just hook it to the connector on the roof. sorry to hear of the roof troubles, hope that turns out ok for you.

 

[icetechaus]

Ron, For the possibility of the high current that you may experience try using one of these ILO individual diodes. The main reason is they will handle the current and they are easy to connect to and heatsink. Bridge rectifier Connect the solar panel wires to either of the AC inputs and the CTEK to the + and - outputs. It will put a high current diode in both the positive and negative outputs of the panel and should give you about 1.2v drop.

 

[ROnEM]

Boots, thanks for the tip on the silicon diodes.

Icetechhouse, I have 10 diodes on the way. They are 15Amp rated as used on solar panels, so should be perfect.

I checked with CTEK and they have said NO - 22v MAX.

Factory Solar pre-wire is only the cable through the walls and roof. Terminates nowhere and your have to provide the solar regulator - hence the CTEK. Two birds - one stone.

So, will just have to put in some cable from the batteries to the drawbar for the solar panel to connect to, until I get a chance to do the thing properly.

Cheers,

Rohan