I have a CTEK (56-864) MUS 4.3 amp battery charger (with comfort indicator pigtail) for my 2004 360 Spider. I connect the charger to the battery through a connection behind the driver's seat that comes out of the carpet (pictured). Its an easy charging solution, thanks for those that pointed this out. The only issue is that the connection coming out of the carpet had a 3 amp fuse (pictured), and I blew that fuse when I tried charging the first time. It seems to me that the correct thing happened. A 3 amp fuse blew when the battery charger put 4.3 amps across the connector. However, I'm stuck looking for an easy charging solution. Does anyone know if 3 amps is in fact the correct rating for a fuse in this connector? It would be ideal if it were a 5 amp fuse instead, but I wouldn't swap for a higher rating (e.g., 5 amp fuse) without good intel (and even then I'd keep a careful eye on the charge). All thoughts welcomed on this, I'm just trying to find a solution. Additional info is that at the time of charging the comfort indicator indicated battery was "red" (<60% charged) and at the time of charging it was about 40 degrees Fahrenheit in the garage. The fuse blew approximately 10 seconds into charging. Thanks. Image Unavailable, Please Login Image Unavailable, Please Login
I would assume that pigtail was already in the car when you got it? I would just update the fuse, it was probably for a different smaller tender. Those pigtails are very universal. No harm, no foul....in my opinion, to upgrade the fuse. Its just screwed onto the positive and negative sides. Your charger is smart enough to know its amperage, especially the Ctek. Hope this helps!
CTEK supplies a 15 amp fuse with their connectors as standard equipment. Alden Sent from my VS986 using Tapatalk
Thanks guys. I'm not sure I understand the response though. Just to be clear, the 3 amp fuse that blew was the fuse in the after-market (non-CTEK) connector that supplies a connection to the battery. I'm assuming the previous owner installed this. This connector comes out of the carpeting behind the driver's seat. The fuse for this connector is hidden from view normally because it comes off the wire in a portion of the wire that is tucked in the compartment behind the driver's seat. The CTEK pigtail (pictured) has no fuse.The CTEK pigtail (which I purchased, it was not in the car beforehand) is just used to fit the CTEK charger into this connection that came out of the carpeting. So are you suggesting that the 3 amp fuse in the connector be upped to 5 amps? or 15 amps? Or are you suggesting that the 3 amp fuse that blew be replaced with another 3 amp fuse? Image Unavailable, Please Login
Look on eBay for ctek battery connectors, you will see that most of them have a fuse attached, you should have the positive pole fused is close to the battery as possible Sent from my VS986 using Tapatalk
I am not sure those are made for battery chargers! A battery tender (trickle charger) only puts out 1.5 amps. A 3 amp fuse has 100% margin. https://www.zoro.com/battery-tender-battery-charger-12vdc-125a-021-0156/i/G3739933/?gclid=Cj0KEQiAnb3DBRCX2ZnSnMyO9dIBEiQAOcXYH9VF3xXTMXCo020VgiIZrbcnDQH3JQRKSoxiDDI1m9YaAnXz8P8HAQ&gclsrc=aw.ds I have a small 6v/12v battery charger and a few minutes after the initial surge I think it puts out about 5-7 amps continuous. I also googled wire amp ratings, and if they are 14 gage "lamp cord" they are only rated to 15 amps. So I would think a 15 amp fuse would be to high. I am not familiar with the CTEK. But since you say its a 4.3 amp charger, the 3 amp fuse is definitely to small!! You would need a 5 amp minimum with possibly a 10 amp to handle the initial surge. I assume the 4.3 amp is a continuous rating. But the instant you make a connection, there is a surge that could blow a 5 amp fuse. There is even a longer surge that can last a minute or minutes after connection depending on the output of the device if its current limited or not. minimum is 5, but 7.5 or 10 would be better.
Not sure who you're referring to, but the fuses I cited above, are what came originally with the charger from the manufacturer. One of them even has the fuse amperage embossed on ththe fuse holder. I personally think the OP should try and find a manual or FAQ for their charger in question, and see what the manufacturer recommends and stick with that. If that fails, try anew charger. After that, if fuses still blow, consider the outlet it's plugged into, any extension cords, and an electrical fault in the car itself. Or some variant of this order.
