Did your Bosch C7 battery charger show a blue light when you tried to use it? I’ve seen it happen before. It’s a pretty weird situation that isn’t all that common, but it’s nothing to worry about.
If you want to know why this is happening, I’ve got the info you need.
But before you read my tips on how to fix this problem, you can watch this short video I’ve made about the different meanings of the blue light on a Bosch C7 battery charger.
When your Bosch C7 charger is starting, it would show blue light as the indicator that it is about to ready. There should be 2 rounds of light rings indicating the level of the battery.
If you have charge the battery for few hours and it is still showing one inner round of blue light, there is a high possibility the the battery is not healthy anymore. In this case, you would need a battery replacement.
4 Causes Of Bosch C7 Battery Charger Blue Light
- Flat Battery
The main reason why this happens is because you’re trying to charge a battery that’s completely dead or flat. For example, when I tried to charge a battery that hadn’t been used for more than half a year, my Bosch C7 batter charger showed me a blue light.
Despite the battery being in good condition, I was shown a blue light because it was flat after being inactive for so long. So, if you’re trying to charge a battery you haven’t used in a long time, that would explain why you’re seeing this light.
Luckily the Bosch C7 battery charger has a power back up feature that is the second last button to the right of the device.
It’s a 12V power back up function for car batteries, and you can find it in the battery’s manual pretty easily on the list of parts, where it’s number 14.
Switch to this mode while having your flat battery connected to the charger, and then leave it alone for 2-3 hours. Check on the battery afterward by switching back to regular charging.
This is the setting on the top left of the battery, and marked as number 12 on the list of parts in the device’s manual.
After you do this, the battery should be functional again and charging like normal. The light will have switched to green instead and the battery will be fully functional.
- Blown Fuse
I suggest you open the cover to reveal the fuse on your Bosch C7 battery charger if the battery is fine. It might be the fuse that’s problematic.
I’ve had fuses blow on my charger before, and yours could have experienced the same. It’s pretty common after a long time of use.
If you see any breakage or smell any burning, you know that there’s something wrong with the fuse. You’ll have to take the broken one off and buy a 10 ampere replacement fuse that fits your charger in this case.
I’ve found them pretty easily online, so you should be able to too. They’re not expensive and come in packs of several pieces, which will have you sorted for the future.
Other Possible Reasons
- Battery Health Analysis
Bosch chargers can perform a battery health analysis to ensure that the device is in good condition. The blue some chargers perform a health analysis of the battery before charging to ensure optimal charging performance.
The blue light may indicate this analysis phase. You don’t have to worry about this. Just let some time pass and the blue light will go once the check is complete.
- Incompatible Battery Type
This goes without saying, but I wanted to mention just in case; don’t try to charge an incompatible battery with the Bosch C7. The device won’t have any idea what to do, and won’t charge your battery.
Instead, it might display the blue light as a way of telling you that it’s performing a check, but the check won’t yield any results. Instead, try batteries that are compatible and they should work fine.
