CTEK D250S charging issues

[jfidds Lurker Find all posts View Profile Close jfidds]

Hi All,

I recently installed a CTEK DB250S in my 150 Prado following the wiring diagram supplied with it, Iv connected the Aux battery positive to CTEK Aux output, negative to ground and CTEK negative and connected the start battery positive directly to the main connection on the CTEK, for some reason the battery isn't charging.. Any ideas? Do I need to install an automotive relay between the alternator, the CTEK and the main battery?

[LeighW Avid PP Poster! Find all posts View Profile Close LeighW]

Cranking battery pos goes to the alternator battery positive terminal.
Service battery pos to aux.

I'm assuming you have a negative running from the aux negative post
to the cranking battery negative post. And you have indicated
you have a negative going to the ctek.

Disconnect the positive lead from the aux positive terminal post.
Get yourself a voltmeter and connect the negative lead of the meter
to the negative terminal of the ctek, connect the positive lead to the alternator
terminal of the ctek, you should see around 12.5V, start the car and it should increase to around 13.5V

Stop car and reconnect aux postive, start car you should see 13.5V or there abouts
on alternator terminal, move test lead to aux battery terminal and you should see
more or less the same there. Move test leads to aux pos and negative terminals
and you should see a similar voltage across them.

[jfidds Lurker Find all posts View Profile Close jfidds]

Thanks for the reply mate, by alternator battery positive do you mean start battery?? Yes i have a negative running from the Aux to start battery then to CTEK and earth.. I am getting 13.8 volts at the aux battery when the car is running but as soon as I turn it off and put a load on it ie 12v fridge it drops straight down to 11v within 10 seconds... Do you have a CTEK fitted?

[LeighW Avid PP Poster! Find all posts View Profile Close LeighW]

Ok now that is a totally different thing, first off if the ctek is charging and the battery is
over 80% SOC the terminal voltage of the aux should be around 14.4V with an ambient of
25C.

The 13.8 could indicate the charger is working hard, the low terminal voltage of the battery
also indicates it is well discharged.

Have you measured the current going into the Aux?

What is the SOC of the battery?

No I don't use a Ctek as I find a VSR setup works much better.

[Fred63 Advanced Member Find all posts View Profile Close Fred63]

there is this post by Black 120 GX
http://www.pradopoint.com/showthread...l=1#post519605
He has a 150 so this may be your answer

[LeighW Avid PP Poster! Find all posts View Profile Close LeighW]

He has indicated he is getting 13.8V at the aux battery, this indicates the Ctek is
charging so the input voltage must be ok and this indicates it is not a 2.8Ltr
but I could be wrong, what model is your 150 jidds?

If its not a 2.8 the Ctek should work ok, if the input voltage is low then he
could fit one of my booster diodes, he could also then revert to a simple VSR
setup if he finds the Cteks taking to long to charge the battery.

[Tar Trek Junior Member Find all posts View Profile Close Tar Trek]

Hi there,

Do these links help?

https://www.youtube.com/watch?v=LPtawOngxWA

https://www.youtube.com/watch?v=g9l-TBaw_B4

Tar Trek

[Guest Close Guest]

I am getting 13.8 volts at the aux battery when the car is running but as soon as I turn it off and put a load on it ie 12v fridge it drops straight down to 11v within 10 seconds... Do you have a CTEK fitted?

Maybe your aux battery has dropped a cell?

[snapper49 Member Find all posts View Profile Close snapper49]

I run a ctek mounted in the rear of my prado to charge a caravan battery Have it connected to my main battery and via Anderson to the van battery I used 6mm paired cable and a 125amp Anderson It does the job well
It only charges when the engine is running hope that helps

I was told not to put a ctek under the hood as they do not like heat
I also run a red arc under the hood (suppose to take engine heat ok) off of main battery to charge 2nd battery under the hood
All work well with no issues