Possible issue with CTEK 250s

[scarecrow73]

I may be experiencing some issues with my CTEK 250s so thought I would go to the experts for some advice.

My 250s is mounted in the rear tub on top of the battery box. I've installed it all myself and up to this point (8 months) have had no issues. Recently I have noticed that the battery (Exide 110ah deep cycle) has not been getting a full charge. I have a voltage gauge which shows volts and it had been sitting on 12.8 constantly when not being charged so all seemed well.

Now, the battery sits around 12.3 - 12.5 even after a decent run. I've checked the voltage at the starter battery and when running, sits around mid 14 volts. With the engine still running I have checked the volts at the 250s and when it is unplugged, shows the same as the starter battery but when I hook it up and the unit kicks in, this then drops to mid 12's with the starter still mid 14.

The 250s has not shown any error lights and sometimes will even shut off with the engine going which doesn't help me when trying to charge a battery. I have replaced the earth lead from the unit to the battery but problem still persists. Sometimes it will show charging up to high 13's and others will just hover around the mid 12's.

Is there a problem with the 250s?? Its still under warranty (2yrs) so will just have to post back to the mob I got it from. Or is there a problem with the wiring or maybe even the battery? The battery is only a couple of months old as it was a replacement for the other new one that pooped itself (apparently a bad weld!!).

Any suggestions would be appreciated. Cheers

 

[scarecrow73]

Anyone?

 

[camo.b]

Bump!
Doesnt sound right.i havnt got a ctek but i have a solar setup for my aux battery.normal charge is 13 somthing volts.battery always sits at 12.9v at night.
Someone will be along soon with some actual help

 

[Old.Tony]

It's funny you should raise this problem as I've just experienced something VERY similar.

Aldi 600W inverter feeds a CTek XS7000 mains charger which chargers an Optima D31A 75Ah spiral-wound AGM (nearly unkillable). Fridge has connections to 12V from the battery and 240V from the inverter, so when the inverter fires up, the fridge stops drawing from the battery and just sucks down the 240V.

I added a battery monitor in the cabin. Cable length prevented me from measuring the current draw, but voltage was pretty accurate (tested with a good digital multimeter). The monitor showed high voltage (14V+) when the engine was running and just 5V when stopped. Fridge would turn off once 240V was gone ... so I was in trouble.

The actual connection from the battery (standard battery post, the D31A can be used as a 900+CCA cranker) is with a typical terminal clamp with cables coming from the clamp, as well as the battery monitor and battery charger all connected directly to the clamp.

I tested the battery with my multimeter and (touching the leads to the clamp) I found the same voltage as my monitor was reporting. I thought "at least THAT's working, but I've blown up my AGM!". That's when I accidentally touched the battery post itself and discovered a nice 12.8V on the battery.

Close examination showed a very fine oxidisation on the inner surface of the clamp, which wasn't allowing all the power through. Cleaned = working again, no need to replace the battery and we're going again!

Check yours?

 

[Tappet]

Ok- I was thinking battery to, So as Tony has done with his check the simple things first and only one thing at time. That way you know what fixed it.

 

[MjWatt]

Hwo do you get around the alternator dropping down to 12 - 12.5 volts after a period of time.

Mine starts around the 14 then drops about about 5 mins?

2013 ST?

 

[scarecrow73]

Disconnected the cable from the starter and gave it a clean, although nothing on it to suggest any build up of crap. Replaced it and hey presto, charger worker perfectly. Straight up to 14.4 volts and all was good. I did say was!!

Has since gone back to what it was doing before, sometimes getting up to only mid to high 13v then after a short drive, the unit has gone back into battery saving mode.

Without too much detail in the supplied book, its hard to tell if this is what the unit is supposed to do. I guess if it detects that the battery is full it may shut down but this is no good if you have a camper trailer connected and charging another battery.

I did stumble across some in that said that the 250s will only run when it detects volts over 12.3 i think. This could explain why it shuts down as I just tested the battery after getting home and it showed about 12.0-12.1 volts. My understanding of the unit was it was designed to overcome the "smart" alternators but obviously not.

I will try the cutting of the green wire as I can't figure out how to unplug the other plug from the neg terminal of the battery.

 

[lakesideguy]

Sorry I don't have THE answer, but hopefully I can put some good karma out there for the future with some tips for common problems with CTEK250S:
Do easiest stuff first...
250S has heat sensor measuring ambient temp around battery. So, if temp too high it will cut back the charge rate so it doesn't cook your battery. Alternatively, if too cold it will increase charge rate so it will fully charge. Never cut off or do anything to prevent it working. Obviously, do not mount under bonnet or near exhaust.
CTEK250S also has an inbuilt voltage control/sensitive relay, so if you have a regulator (Redarc) or another relay in the same circuit, they can argue with each other. Remove extra regulator/relay and test.
CTEK not water proof - do not mount under vehicle if you want to last
Cables too thin or all cables not same thickness - if not sure, cannot have cable too thick
Bad crimp/solder job between a cable and lug - change one out at a time and check
Bad connection between lug and CTEK/battery/chassis - change and check
Bad connection from too many accessories lumped onto one bolt. Even though all touching, if not enough surface area, voltage will be restricted. Remove all unnecessary stuff and check. Do yourself a favour spend $12, buy a multi-lug bus bar and never have a problem.
Earthed onto part of vehicle with low conductive material (eg: modern composites look like metal) or part is isolated by low conductive material (rubber mounts) - check by changing location
Bad earth, it may look good but not enough clean surface area for contact will be enough to stop everything - change location and check with multimeter
Bad battery - 98% of batteries that fail for warrantable reasons (manufacturer's fault), occur in the first 48hrs. Check by changing battery or by disconnecting and charging with a different 240v charger, then check difference
Parasitic power leak - CTEK is a computerized charger running through a charging program so sometimes can be confused if constantly having to start again - Check by disconnecting one power sucking gadget at a time to see if it makes a difference
as part of the safety feature, CTEKs do have a minimum voltage to decide with it is connected correctly to a battery or reverse polarity or just to a something that is not a battery. It does vary for the model and how old it is, but if you have this issue, it is generally around the 5 volt range when using a 12v charger.
Call Baintech
Visit local auto electrician
This is all I can remember off the top of my head. Good luck

 

[J13NST]

with d40 with smart alternator which is built from late 2010 or 2011 i believe.
need to be hooked up to solar panel connection not alternator.

You can use a CTEK D250S Dual in a vehicle with a smart alternator, provided you have an automotive relay installed.
CTEK Sweden have devised a simple solution for using your CTEK D250S Dual with a smart alternator. By including a 30A automotive relay into your system, you can successfully install a CTEK D250S Dual into your modern vehicle with a smart alternator.

The CTEK D250S Dual DC-DC charger will charge, condition and maintain your dual battery system, with the ability to charge from both your alternator while your vehicle is running, and your solar panels while your vehicle is turned off. The relay is designed to go between these two power sources and your CTEK D250S Dual, and is activated by vehicle ignition. Allowing the CTEK D250S Dual to work with a smart alternator.

http://www.baintech.com.au/faq/can-i-use-a-ctek-d250s-dual-in-a-vehicle-with-a-smart-alternator