CTEK 250S connection with Smart Alternator

PauSum

PauSum

Forum Member
Joined
Aug 1, 2008
Messages
321
Location
Perth Australia
Car Year
2005 and 2015
Car Model
Forester and Outback
Transmission
5 speed manual and 6 speed CVT
Fazed said:
I went with using a Ctek DC to DC charger, which is suitable for both smart and non-smart alternators.

https://www.ctek.com/au/en/chargers/D250S DUAL

Basically it will charger at 14.4V with and input voltage down to 12. It has an input so my 80W solar panel can be connected and it's inbuilt with an MPPT tracker for it. And solar is a good idea if you stay at a campsite for a little while.
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Fazed, i guess you connect the alternator to the D250S at the solar contact point via a relay?
Also where do you find the ignition wire from your XV?

I bought the same charger but not sure where to find the 'ignition' wire in my MY14 outback.
 
Thank you Kevin,

I guess; as the relay needs to connect to the "ignition", it needs to be in the engine bay. Also with me having very limited knowledge about electronic, where is the "ignition" of the car - is it around the starting motor etc?
 
I don't have intimate knowledge of a MY14 OB so maybe someone can chime in with suggestions or, even better, a circuit diagram. Armed with a multi meter I would be testing around the fuse box in the engine bay for an ignition link to connect to the relay. The disadvantage with this set-up is that you don't get the auto-feed back to your starter battery from the CTEK with a solar panel if your aux battery is full, but I guess it's a small price to pay.

PS - thinking about the solar feed to starter - this could also be accomplished with another relay i.e. one that connects the starter battery to the alt input on the CTEK when the ignition is off. Simply put, when the ignition is on the starter battery is connected to the solar input, when the ignition is off the starter battery is connected to the alternator input on the CTEK. Can probably do this with one relay.
 
I like the look of that ctek unit - isolates and switches sources nicely, has temp sensor to control output voltage, and will provide full output voltage even if the solar panel output is a bit low.

You might want to add an external isolating switch to be able to start off your aux battery if the starter is dead...
 
Will it work if I use a "add a circuit" fuse tap (with a 5 amp fuse) on fuse 15 in the fuse panel which indicates "ignition coil" in the user manual and connect the wire to pin 85 of the relay?
 
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Got a reply from an ebay retailer's advice regarding the "ignition" :newmulti:

"It needs to be a wire (any wire) that is live when the ignition is in the "on" position (not acc)

A lot of cars, the wipers only work when the key is "on", that would be a good place to start.

Failing that, you just need to probe wires under the bonnet until you find one.
Regards"
 
Wow, you actually found a helpful seller on ebay, usually they give no reply at all in the states, or have some smarmy remark.
 
The power windows in my MY'03 don't work unless the ignition is on - is it the same in the MY14? (I actually hope not as it is a PIA!)

Another thought; I wonder if there are any issues with connecting the CTEK "alt" input to the starter battery as well (via a circuit breaker or fuse)? It may or may not activate when the smart alternator is running but will activate at rest and would then feed any excess from the solar panel back to the starter battery?
 
Yes Kevin, the power windows do work on my14 even when the ignition is off but n 'acc'.

According to the ctek manual, the charger will automatically choose solar to top up etc if the alternator is connected to 'alt' - or that is how I read it. Not sure how it works with wiring at the solar as well.
FYI, I quoted from an autoelectrician yesterday his initial quote was $abt $350 plus $110 for the relay fitted. He dropped to $350 fitted including the relay after much discussion. Not decided yet
 
digdug18 said:
Wow, you actually found a helpful seller on ebay, usually they give no reply at all in the states, or have some smarmy remark.
Click to expand...

Lucky me :)
 
For my dumb alternator setup I have both ALT and SOLAR permanently connected as I have solar panels on the roof of my camper. When the engine is running the CTEK indicates power coming from both sources.
 
Good to know Kevin,
I may try connecting the same this weekend and see how things go.
 
I think I have finally found the confidence to set this up after much searching, discussions, probings and testings.

There are 3 fuses (1, 23 and 24) in the fuse box that has power when the key is in the "On" position and when the engine is started.

Owning to the space issue (the way the cover is closed and I'm going to do the same to fuse 8 to install the LED light bar), I am adding a circuit to fuse 23 (rear wiper and washer) for connecting "ignition" to pin 85 of the relay.

As I happen to have a 30A 5 pin relay at home, I'm going to ignore pin 87a of the relay as I will connect the solar panel (when I bought it) to the charger fitted in the trailer.

I set all connections up without the thick wire today and tested the voltage at the relay pin 30 using positive probe of the voltmeter and the negative probe of the voltmeter connected to the negative pole of the battery and have the following outcome:
- key at "Acc" position - voltmeter showed random mmV
- Key at "On" position and engine off - voltmeter showed 12.7xV (roughly from my memory)
- Key at "On" position and engine on - voltmeter showed 14.54V :cool:

I will connect this up with the thick (6 B&G) wires ending in the Anderson plug when the manual circuit breakers arrived.

The only queries needing proof now are:
- I think I'll need this to connect pin 30 of the relay to the thick wire
- I probably will connect to the alternator connector of the charger initially to see whether the battery will be properly charged or not
- Does my car really have a smart alternator? :rolleyes:
 
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PauSum said:
Does my car really have a smart alternator? :rolleyes:
Click to expand...
I suspect you do, but ...
The best way is to start the car and run (drive) it for a few minutes while monitoring the battery voltage. If it stays up around 14.2/14.3 then the answer is no. A smart (what a misnomer!) alternator/cpu combo will drop that to low 13's or even high 12's, to save you a poofteenth of a ml of fuel per tankful.

Also, you need to ensure that the DC-DC charger max output does NOT exceed the auxiliary battery's max charge rate. In my case that limited my charger selection somewhat, to a 20A model. That is also an issue for parallelled battery systems.
 
Does the max charge rate show on the battery? I'm using the ctek D250S only so the max charging cuŕrent is 20a only too.
 
If you mean is that info marked on the battery, the universal answer IMOE is no, you need to look up the specs on the interweb. The same as the max temp for AGM's - some are OK for under-bonnet application but many are not.
 
You don't need to worry about max charge rate with the CTEK - it has a temperature probe that you attach to the battery and it will regulate the charge based on the temp of the battery.
 
Good point Kevin!
 
Sounds as if you are gradually getting a handle on this electrical stuff, PS.

Good on you for your perseverance, mate :poke: :cool:.
 
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