I rarely use my second car, as a result, the battery often drains too much by the time I need it. I have a slow charge battery pack which works if I want to wait a while to get to the minimum level to turn over, but I wanted something to ensure my car is always ready to go so I purchased a trickle + float charger for my car.

Right now, I am using alligator clips with the hood open because I am concerned about gas/sparks. The charger system I purchased came with permanent clips, but I can't figure out the best way to attach them (they are full circle, not semi-circle). The permanent ones look like they should fit around the screw used to hold the wire clips to the battery terminals. However, when I tried to fully unscrew the nut wouldn't come all the way off and I thought this was by design.

What I would like to do is to charge the battery with the hood fully closed so the kids don't try to reach inside. I was concerned that using alligator clips with the hood closed would be less safe (more likely to spark/combust gases), but I am not sure how to best attach the permanent wiring.

Here are my main questions:

  1. Is it safe to charge using alligator clips with hood closed? If not, is it safe with the permanent clips (or are these actually only for something more exposed like motorcycle?)
  2. If I can keep the circle clips connected, it is okay to have the wire sticking out the side of the hood all the time (if it reaches) as long as I put the weather proof cover over?

If not, its not the big a deal for me to pop the trunk and disconnect before I go.

Right now, I only connect alligator clips with the hood open when the kids aren't home and then disconnect. I don't always remember to plug it back in. Appreciate advice on what is safe and best way to setup an easy to connect/disconnect option.

Here is my setup:

showing open hood with battery and charger cables

close up of screw/nut + connector

  • Not sure which type of charger you actually purchased. Personally, I wouldn't use a trickle charger. Since it is a float charger, it may be okay. The better way to go is to get a battery tender type (Yes, there's a brand, but I'm referring to the type, which is a tender. Several brands out there which do this.) A tender will keep the battery charged without overcharging. A trickle charge will continue charging at a slow rate which will ultimately damage your battery. The tender should also extend the life of the battery because of the way it works. Jul 7, 2021 at 22:39
  • @paulster2 I believe this is a maintainer like the tender --> Harbor Freight / CEN-TECH 12v Deluxe Battery Maintainer And Float Charger. I found it from reading battery tender reviews saying is was a suitable alternative.
    – HelpEric
    Jul 9, 2021 at 15:35

1 Answer 1


Two ways around this:

For the red one, you can cut a segment out of the terminal so it will slide onto the bolt.

For the negative, you can bolt to the other end of the negative cable.

Another possibility for the red one is to find one of the live wires into the fuse box or even a wire that is permanently live into a relay and connect there.

Whatever connection you use, make sure a fuse is in the supply side - there may be one already I may have missed it. A 10A fuse is about right for these top-up chargers.

  • Under the rubber boot on the positive cable end, there is the same configuration of bolts/nuts/connectors and can be used for the uncut eye of the float charger. My battery tender is connected in that manner with zero complications other than the boot doesn't fully enclose now.
    – fred_dot_u
    Jul 7, 2021 at 17:47
  • @fred_dot_u that was my thought, but it seems like the bolt isn't meant to come off the screw - I didn't want to try to hard and break it off permenantly. When not plugged in, do you secure the wires anyplace special under the hood, let them stick outside?
    – HelpEric
    Jul 8, 2021 at 15:59

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