Battery Fuse

I have a very quick, and probably stupid, question about having a fuse on my batteries.

I’ve been wanting to get my two external batteries hooked up to my Simplex 4005 to clear the battery trouble. I was just about to plug them in today, looked at the diagram on the door, and realized that I completely forgot about the 15 amp fuse that should be wired in with those.

The batteries are in need of charging, and I’ve been wanting to make sure the panel’s battery charger is working and in good shape.

Is it alright to plug the batteries in at least for a little while without that fuse, or is something I should absolutely not do until I obtain a fuse?

Furthermore, where can I get the correct fuse?

Thanks!

I would recommend having the fuse in the circuit. However, if very careful, and double-triple checking the battery polarity, you can charge the batteries without the fuse. The charging current is limited by the battery charger chip on the power supply. The fuse is there to prevent the batteries from melting in the case of a catastrophic failure of the system or connecting the batteries backwards. There is a big high current diode on the power supply board that is there to blow the fuse if the batteries are connected backwards.

The fuse is a standard AGC15 amp fuse. These are available at electronic parts dealers, Lowe’s, Home Depot, and auto parts dealers.

Excellent, thank you very much.

I will start looking into a fuse. For now, I’m pretty darn sure I have the right polarity, being that I plugged in an alarm to the batteries the way they are, and it worked, but barely.

Like I said, they’re desperately in need of a charge; haven’t had them plugged into a panel for a few years now. They were going strong a couple years ago, and the things are marked 2006, so we’ll see how well they do. I probably need to get a meter and see how many volts they’re putting out.