I don't have a cap for a nine volt battery so I am connecting to it with copper wire. Which connector is positive?

Have I wired these up correctly? Battery and wires

  • 4
    \$\begingroup\$ Can I suggest taping over one of the terminals to stop a short circuit as your using multicore cable so one could touch the other terminal and then make the battery get very hot. \$\endgroup\$
    – Dean
    Commented Jan 8, 2012 at 0:28
  • \$\begingroup\$ Already happened -- luckily I noticed and covered the middle and one terminal with a rubber band. \$\endgroup\$
    – aaazalea
    Commented Jan 8, 2012 at 0:52
  • \$\begingroup\$ Why all the downvotes? \$\endgroup\$ Commented Jun 21, 2012 at 14:04
  • 1
    \$\begingroup\$ @Toby - Mine because you shouldn't solder on batteries unless they have soldering tabs. \$\endgroup\$
    – stevenvh
    Commented Jun 21, 2012 at 14:05
  • 2
    \$\begingroup\$ So tell me I should do it differently, instead of saying it's a bad question. The object of asking a question on SE is learning, and without asking a question, even if it's the wrong question, I can't do that. \$\endgroup\$
    – aaazalea
    Commented Jun 23, 2012 at 17:06

3 Answers 3


Look at the body of the battery - it will tell you.

The round one is positive, the crown shaped one is negative.

enter image description here


You have them reversed.
The smaller round "male" one is positive.

enter image description here


Making your own conector:

Find a dead 9 volt battery.
Tear its head off - aka, remove the terminals.
This will push onto another battery and provide you with terminals.

Note that on the connector which you are making the terminals are reversed.
On the connector the round pole is negative (unlike on the battery).

This polarity for battery connector only:

enter image description here


You need a basic multimeter.
In Cleveland you should be able to find one for $1 or so in a yard sale / garage sale ... or free. If you can't find one and can't afford one email me and tell me why I should ask somebody to give you one. Good enough story and I'll arrange for someone to do so. ((I'm in NZ :-) ).

You need a soldering iron.
Ideally temperature controlled but anything no too large is a start. Smallish tip.

What are you powering with your battery?
Who is Grandawn?


You should never solder batteries unless they have soldering tabs. 9V battery snap connectors cost next to nothing,

enter image description here

and you'll avoid mistakes if you would get batteries like the one on the left:

enter image description here

The full size image seems to be inaccessible, but if you have a good look you'll see that the "+" marking on the left battery is on the wrong side. (I've been assured that it isn't photoshop'd.)


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