As an FYI in case this helps anyone. I emailed CTEK support and got the below response regarding this issue (which hasn't resurfaced for me by the way)
Flashing lights does not generally mean that the charger is broken. This explanation is also if green is steady and the orange light is flashing.
It means that there is a bad connection between the charger and the battery, and that can be
1. Visible - like broken leads, dirty battery poles, bad connection when charging via chassis, cable that has become detached from the clamp/eyelet, quick connector that is not accordingly fixed together.
2. not visible, - Sulphation problems, often due to deep discharge or long time with low charge. A sulphated battery has a layer of insulating lead sulphate on the inside. It does not cover the inside fully as you can still detect voltage across the battery. This kind of bad contact is inside the battery, and the charger cannot start charging.
In both cases the charger does attempts to reach the goal, by sending rapid peaks of tension, pulses of energy, until the battery starts to accept the charge. That is the flickering.
What to do?
1. Move the connections a little. Check that the quick connector is properly assembled. Check inside the connectors if the pins are OK. Check all visible possibilities. If connection is established, the charging indication light will be steadily lit.
2.Sulphated battery. Leave the charger connected for maximum 24 hours. If it has not been able to penetrate the sulphate layer after that, the battery is most probably in very bad shape and it might to be best to consider a replacement . If the yellow or green lamp lights steadily, the charger has activated the battery and it will probably work, but it is nevertheless soon at the end of its service life.. Let it charge for a couple of days to boost the power, while being aware at the same time that the battery will soon be dead. There are coarse sulphate crystals which no charger in the world can break down.
The flashing might also be a fault in battery cell if the flashing appears after some hours of charging.
If the battery started charging in the correct way, with the orange lamp, and then starts flashing after a while, this is due to a break somewhere. The easiest explanation is that the connection has simply fallen off, but it could also be a break inside the battery.
If the charger continues to flash no matter what battery you connect it to, it obviously has developed a fault.
Flashing lights does not generally mean that the charger is broken. This explanation is also if green is steady and the orange light is flashing.
It means that there is a bad connection between the charger and the battery, and that can be
1. Visible - like broken leads, dirty battery poles, bad connection when charging via chassis, cable that has become detached from the clamp/eyelet, quick connector that is not accordingly fixed together.
2. not visible, - Sulphation problems, often due to deep discharge or long time with low charge. A sulphated battery has a layer of insulating lead sulphate on the inside. It does not cover the inside fully as you can still detect voltage across the battery. This kind of bad contact is inside the battery, and the charger cannot start charging.
In both cases the charger does attempts to reach the goal, by sending rapid peaks of tension, pulses of energy, until the battery starts to accept the charge. That is the flickering.
What to do?
1. Move the connections a little. Check that the quick connector is properly assembled. Check inside the connectors if the pins are OK. Check all visible possibilities. If connection is established, the charging indication light will be steadily lit.
2.Sulphated battery. Leave the charger connected for maximum 24 hours. If it has not been able to penetrate the sulphate layer after that, the battery is most probably in very bad shape and it might to be best to consider a replacement . If the yellow or green lamp lights steadily, the charger has activated the battery and it will probably work, but it is nevertheless soon at the end of its service life.. Let it charge for a couple of days to boost the power, while being aware at the same time that the battery will soon be dead. There are coarse sulphate crystals which no charger in the world can break down.
The flashing might also be a fault in battery cell if the flashing appears after some hours of charging.
If the battery started charging in the correct way, with the orange lamp, and then starts flashing after a while, this is due to a break somewhere. The easiest explanation is that the connection has simply fallen off, but it could also be a break inside the battery.
If the charger continues to flash no matter what battery you connect it to, it obviously has developed a fault.
