Loose Battery Connector


#1

Some months ago, I had a new battery installed on my 2000 Subaru wagon. Since then, the starter, intermittently doesn’t engage…depress cluch pedal to the floor, turn ignition key to start, and zilch…silence.

A volt meter shows yellow or red L.E.Ds. Digital readout at barely 13 volts.

I discovered that the battery connector to the Positive terminal just can not be tightened securely, regardless of how much I tighten the lock nut; the connector swivels on the post or rocks slightely from side to side even though I’ve tightened the lock nut till it can’t be tightened any more. The lock nut threads are still in good shape.

How can I get the connector to tighten securely on the battery terminal post?


#2

Get a new battery terminal or a new battery cable. $12 max at most auto parts stores.


#3

Well, I just replaced the battery cable and, guess what? The connector also swivels and rocks from side to side on the post. The lock nut just can’t be tightened enough to prevent it. Now what?


#4

There is something wrong with that new battery. It sounds like the post is too small. Bring it back to where you bought it and have them check it out.


#5

Is the cable end a lead one and is the split being compressed together? If so, remove the pinch bolt and either file or hacksaw a little bit of lead out of the split. This will allow the pinch bolt to compress the end more.
(Within reason of course.)


#6

I just looked at our 03 Subaru OEM terminal. the positive one has a rubber “washer/spacer” that fits under the pos terminal and also fills up space between the two pinch pieces of the terminal. Do you have all these pieces? If not, you may need to construct a rubber spacer to fill the gap the washer/spacer is intended to fill. We also owned a 99 but I don’t remember if this arrangement was in place for it.


#7

Well. I filed the split end down a nice amount and the connector still swivels. I then got a small piece of sheet metal from a place that makes drain gutters for houses. I cut a piece to the height/circumference of the battery post. Put it on the post and attached and tightened the connecter. No more swiveling, BUT a volt meter shows the battery voltage at 12.3 volts (too low) and the L.E.D. on it glows yellow or red.
I can’t readily go back to where I purchased the battery since it’s about a thousand miles from here.
What can I do at this point other than beat my head against the wall?


#8

The sheet metal is not a good conductor. Can you squeeze some copper wire in to fill the gap?

Better yet, contact the manufacturer of the battery and explain the problem.


#9

The battery is discharged, which is not surprising, given the connection problem you’ve been having. Charge it up. Then take the car to a place like AutoZone that will load test the battery to see if it is still good, and also get the alternator tested.

I see a problem with your solution. The piece of sheet metal you are using is probably aluminum. In contact with the lead of the battery post, it will corrode, ad since aluminum oxide is white, it won’t be obvious when you look at it. It would be better to fix the problem properly. Is the replacement terminal just like the original or is it a more generic type?


#10

I totally agree with all of NYBo’s comments. Not only will aluminum corrode it also does not stand up to high current loads and will soon burn up. This is exactly why aluminum wiring was banned from home use after a number of homes went up in flames.

If a thin piece of sheet metal tightens it up then simply whacking a little more out of the split in the cable end should accomplish the same thing and not cause any future problems. File some more.


#11

Copper sounds like a winner. I’ll try and get hold of a small, flat, thin, piece of copper and cut it to size if need be, or failing that, some copper wire. If all else fails, I’ll contact the battery manufacturer.
Incidentally, all the car’s electrics are working fine off the battery… power windows, ventilation blower, sun roof, and, so far, the starter is engaging. So, the charging system is keeping the battery charged enough even though the volt meter shows the battery at less than ideal charge.
Anyway, thanks, everyone, for the feedback.


#12

There were alot of problems when AL wire first hit the market but it has become much more accepted and used, especially lately with the cost of CU, since the dangers are well known and accounted for. AL wire is used almost exclusively for the pole/box to meter drop into the home. AL wire suffers from the aforementioned corrosion issue so a corrosion inhibiting “jelly” must be used on all connections. Switches and outlets are designed specifically for AL wire use to combat galvanic action and reduce oxidation issues. Typically, AL wire should be one gauge heavier than the appropriate CU conductor.

The battery terminal is likely smaller diameter than the prior/OEM battery. Just buy a new end that fits, cut off the old terminal, strip back the insulation and attach the new terminal.


#13

Copper sounds like a winner. I’ll try and get hold of a small, flat, thin, piece of copper and cut it to size if need be, or failing that, some copper wire. If all else fails, I’ll contact the battery manufacturer.
Incidentally, all the car’s electrics are working fine off the battery… power windows, ventilation blower, sun roof, and, so far, the starter is engaging. So, the charging system is keeping the battery charged enough even though the volt meter shows the battery at less than ideal charge.
Anyway, thanks, everyone, for the feedback.


#14

Most hardware stores can sell you some sheet copper, if you want to go that route.


#15

That is correct. The real problem is when the aluminum wire is connected to copper. Special switches and outlets must be used and the paste need to be used when connecting with copper wire. Problems creep in because people don’t recognize the aluminum cables and wires for what they are and don’t know what they are supposed to do with it if they do. This will be the OP’s problem too.

Aren’t there different size battery posts and different size clamps to match? Trance, did you buy a lead clamp or one of the OE type that looks like it could have been made from metal from a tomato juice can? A careful look around a well-stocked auto parts store may fix your problem.


#16

I agree there may not be a problem with aluminum from the pole to the box. The wiring from pole to box at my house is aluminum. I was referring to the thermal differences between alum. and copper as used inside the home.

Same thing. Thermal variations produced bad connections which in turn produced heat followed by fire. Bottom line here is that anything placed between the battery post and cable end is going to be a problem, alum., steel, or whatever.

(I’ve actually run into this a few times in the past in which the cable end would not clamp down on an apparently small battery post but it’s been quite a few years since I’ve seen this problem. My memory is not good enough to remember the battery make, etc. but I do remember that widening the slot in the cable end cured them. It does seem like one or two of them required shaving about 1/8" out of the cable end slot.)


#17

I’m not sure I understand your thermal issue. The conductor feeding the entire home is AL and carrying all of the house current. It would seem that any thermal issue would be more of a problem with a 200 amp feeder than any smaller circuit inside the home. Just like the conductors inside the home, it must be sized to supply the current without an appreciable rise in temperature. As I mentioned, that is why AL conductors are usually sized one gauge heavier than CU. For example, a 100’ 40 amp circuit, you’d use #8 CU or #6 AL.

Oxidation is a much bigger problem with AL wire. AL oxidizes readily and forms a protective layer. That leads to high resistance connections and heat. Leave off the jelly/paste and I guarantee you’ll be having problems in short order. Ignore those warning signs and your house could burn down. With the price of copper today, we’ll be seeing more and more DIYers using AL wiring and I suspect that lack of knowledge on the specific installation differences will lead to a spike in fires once again just like when it first started being used.