Battery terminals
 

Question : what is the proper way to clean battery
terminals and leads that aren't making a good
connection?

Last week, after charging my battery when it was
flat, I noticed a lot of that bluish-white salt stuff
built up in the negative battery lead. I cleaned it
off and reattached the lead, and then as I was
doing up the nut with the spanner, I got a massive
spark discharge and burning bits of stuff flew off.
I take this to mean that the lead is not making a
good connection to the terminal, and the spanner
caused a connection when it must have come
into contact with the terminal properly.

Battery terminals
 

In article
>,
Old Wolf > wrote:

> Question : what is the proper way to clean battery
> terminals and leads that aren't making a good
> connection?
>
> Last week, after charging my battery when it was
> flat, I noticed a lot of that bluish-white salt stuff
> built up in the negative battery lead. I cleaned it
> off and reattached the lead, and then as I was
> doing up the nut with the spanner, I got a massive
> spark discharge and burning bits of stuff flew off.
> I take this to mean that the lead is not making a
> good connection to the terminal, and the spanner
> caused a connection when it must have come
> into contact with the terminal properly.

Hmmm I bet you were putting the positive terminal back on, and your
wrench touched something grounded. You could have had a battery
explosion... glad your ok. Look at your wrench; on the end opposite to
the end you were using, you'll probably find a burn mark. Another burn
mark will be on the car where the wrench touched.

You really should always take the negative cable off first when
disconnecting a battery. When reconnecting, the negative goes on last.
That way if your wrench touches something with ground potential, your
safe. (However, if you wrench should simultaneously touch both battery
terminals/posts you'll still get the big arc. Even though possible this
is a little more difficult to do by accident as most wrenches aren't
that long.)

Google a little, you'll find a good bit about this. There is also a
'safe' order to connect and disconnect jumper cables... again Google
away.

Auto parts stores have special battery terminal brushes... they're cheap
and work great. You can also submerge the cable end/s in a mixture of
baking soda water and the corrosion salts will boil away. The baking
soda method doesn't work well if the terminals are oily or greasy. Keep
the baking soda mixture out of the battery.

Once you get the terminals clean and installed, giving then a good
coating of heavy grease will prevent further corrosion. Be sure to pack
it in well under the terminal. (Acids don't attack grease)

Erik

Battery terminals
 

Erik wrote:

> > Last week, after charging my battery when it was
> > flat, I noticed a lot of that bluish-white salt stuff
> > built up in the negative battery lead. I cleaned it
> > off and reattached the lead, and then as I was
> > doing up the nut with the spanner, I got a massive
> > spark discharge
>
> Hmmm I bet you were putting the positive terminal back on, and your
> wrench touched something grounded.

No - I attached the positive lead first and did its nut
up and put the protective cover on; and then attached
the negative lead, and then as I was doing up the nut
on the negative lead, the spark happened. I was
standing clear of the car and the spanner didn't
touch anything apart from the negative stuff.

> Auto parts stores have special battery terminal brushes... they're cheap
> and work great. You can also submerge the cable end/s in a mixture of
> baking soda water and the corrosion salts will boil away. The baking
> soda method doesn't work well if the terminals are oily or greasy. Keep
> the baking soda mixture out of the battery.
>
> Once you get the terminals clean and installed, giving then a good
> coating of heavy grease will prevent further corrosion. Be sure to pack
> it in well under the terminal. (Acids don't attack grease)

OK, I'll do that. Any particular sort of grease?

Battery terminals
 

In article
>,
Old Wolf > wrote:

> Erik wrote:
>
> > > Last week, after charging my battery when it was
> > > flat, I noticed a lot of that bluish-white salt stuff
> > > built up in the negative battery lead. I cleaned it
> > > off and reattached the lead, and then as I was
> > > doing up the nut with the spanner, I got a massive
> > > spark discharge
> >
> > Hmmm I bet you were putting the positive terminal back on, and your
> > wrench touched something grounded.
>
> No - I attached the positive lead first and did its nut
> up and put the protective cover on; and then attached
> the negative lead, and then as I was doing up the nut
> on the negative lead, the spark happened. I was
> standing clear of the car and the spanner didn't
> touch anything apart from the negative stuff.
>
> > Auto parts stores have special battery terminal brushes... they're cheap
> > and work great. You can also submerge the cable end/s in a mixture of
> > baking soda water and the corrosion salts will boil away. The baking
> > soda method doesn't work well if the terminals are oily or greasy. Keep
> > the baking soda mixture out of the battery.
> >
> > Once you get the terminals clean and installed, giving then a good
> > coating of heavy grease will prevent further corrosion. Be sure to pack
> > it in well under the terminal. (Acids don't attack grease)
>
> OK, I'll do that. Any particular sort of grease?

I just use wheel bearing grease... I have an old tub that became
contaminated, and was delegated to battery use years ago, I think it
might be sodium base if I recall correctly. I don't think I would use
Moly-disulfide or the like. Others here might have more info.

Strange you got such a big spark... were the lights or something on?

Erik

Battery terminals
 

to get that spark either something is turned on or you have a short
somewhere. I guess the clock runs all the time so a very small spark
might be normal.

Battery terminals
 

Old Wolf wrote:
> Erik wrote:
>
>>> Last week, after charging my battery when it was
>>> flat, I noticed a lot of that bluish-white salt stuff
>>> built up in the negative battery lead. I cleaned it
>>> off and reattached the lead, and then as I was
>>> doing up the nut with the spanner, I got a massive
>>> spark discharge
>> Hmmm I bet you were putting the positive terminal back on, and your
>> wrench touched something grounded.
>
> No - I attached the positive lead first and did its nut
> up and put the protective cover on; and then attached
> the negative lead, and then as I was doing up the nut
> on the negative lead, the spark happened. I was
> standing clear of the car and the spanner didn't
> touch anything apart from the negative stuff.
>
>> Auto parts stores have special battery terminal brushes... they're cheap
>> and work great. You can also submerge the cable end/s in a mixture of
>> baking soda water and the corrosion salts will boil away. The baking
>> soda method doesn't work well if the terminals are oily or greasy. Keep
>> the baking soda mixture out of the battery.
>>
>> Once you get the terminals clean and installed, giving then a good
>> coating of heavy grease will prevent further corrosion. Be sure to pack
>> it in well under the terminal. (Acids don't attack grease)
>
> OK, I'll do that. Any particular sort of grease?


I think the reason your battery was flat involves that big spark you
saw. That indicates a large draw on the battery. There should only be
a small crackle when the post tightens up, not a chunk blowing arc.

I use dielectric grease over my terminals to help keep corrosion down.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
'New' frame in the works for '08. Some Canadian Bush Trip and Build
Photos: http://mikeromainjeeptrips.shutterfly.com

Battery terminals
 

why was your battery flat? maybe your alternator is short. I am not
sure what the best way of tracking down a short would be. the short is
probably not in an area protected by fuses or a fuse would have blown.

Battery terminals
 

On Jul 13, 4:31 am, Mike Romain > wrote:
> I think the reason your battery was flat involves that big spark you
> saw. That indicates a large draw on the battery. There should only be
> a small crackle when the post tightens up, not a chunk blowing arc.

I recharged the battery and tested with an ammeter before
connecting the negative lead, and it showed 600mA being
drawn. I believe this is quite high (my other car of the same
manufacturer and similar year only draws 200mA). I might
have to take it to an electrician to get it checked out.

(I googled and it suggested doing voltage drop testing on
the alternator, but my alternator is in an awkward place).

> I use dielectric grease over my terminals to help keep corrosion down.

Right, so you apply that to the terminals before connecting
them?

Battery terminals
 

"Old Wolf" > wrote in message
...
> On Jul 13, 4:31 am, Mike Romain > wrote:
>> I think the reason your battery was flat involves that big spark you
>> saw. That indicates a large draw on the battery. There should only be
>> a small crackle when the post tightens up, not a chunk blowing arc.
>
> I recharged the battery and tested with an ammeter before
> connecting the negative lead, and it showed 600mA being
> drawn. I believe this is quite high (my other car of the same
> manufacturer and similar year only draws 200mA). I might
> have to take it to an electrician to get it checked out.
>
> (I googled and it suggested doing voltage drop testing on
> the alternator, but my alternator is in an awkward place).
>
>> I use dielectric grease over my terminals to help keep corrosion down.
>
> Right, so you apply that to the terminals before connecting
> them?

600 milliamperes is far too high for quiescent residual current. Now, when
you
first connect the battery, some systems may temporarily draw increased
levels
of current but they should quickly settle down. Normally you should not
draw
more than 30-40 ma, or a little higher, at steady state with everything
turned off.

The 600 ma level is not acceptable if it stays that way.

You can slather the terminals with dielectric grease before you connect
them.
You can give them a heavy coating after you connect them, but you will not
get the same level of protection.

Battery terminals
 

Old Wolf wrote:
> On Jul 13, 4:31 am, Mike Romain > wrote:
>> I think the reason your battery was flat involves that big spark you
>> saw. That indicates a large draw on the battery. There should only be
>> a small crackle when the post tightens up, not a chunk blowing arc.
>
> I recharged the battery and tested with an ammeter before
> connecting the negative lead, and it showed 600mA being
> drawn. I believe this is quite high (my other car of the same
> manufacturer and similar year only draws 200mA). I might
> have to take it to an electrician to get it checked out.
>
> (I googled and it suggested doing voltage drop testing on
> the alternator, but my alternator is in an awkward place).
>
>> I use dielectric grease over my terminals to help keep corrosion down.
>
> Right, so you apply that to the terminals before connecting
> them?

Because it is dielectric grease, it is non conductive so I clean the
lead nice and clamp it tight before adding the grease coating.

I live in the salt/rust belt and even with grease the older batteries
and cable need a clean every 2-3 years or they will give trouble.

Sometimes you can narrow down a draw by pulling fuses. You pull one at
a time looking for the drop, then you have the circuit in question
narrowed down at least.

Mike