Hi and thanks in advance for any help,
My problem is my battery is no longer being charged while I drive the
car. I've had the battery tested and it's fine, the alternator has
been tested and it's fine. Could the voltage regulator be bad? I
would be able to at least start the car for a period of ~24 hours if I
drove it for about an hour each day. Now, it won't start at all once I
shut the car off which leads me to believe that the battery is no
longer being charged at all while I'm driving. After I jump the car it
Thanks for any help.
It may not be related to your battery if the car is not starting but
who told you the car is charging ok?
What sort of voltage do you measure across the battery with the car
running? It should be 14.5 V. Turn the head lights on. The voltage
should not appeciably drop.
Turn the car off but leave the head lights on. The voltage may drop to
about 12.5 volts or so but should not drop appreciably below that
If it does drop and the car does not start, my first suspect would be
the battery or the wires to the battery (including ground).
If it does not drop yet the car does not start, it could be starter
related. Perhaps you have a bad connection from the battery to the
engine. See if hooking a booster cable (negative side only -- leave
positive hanging) from the battery (-) to a large hunk of metal on the
engine helps the starting process. If it now starts, you have a bad
contact in your ground.
Also check the wire from the battery (+) to the starter - it could be
that it has corroded contacts.
The above is absolutely where I would start.
Also, how old is the battery, in years and miles?
How many times have you jumped it now?
Jumping does reduce battery life.
A bad battery will reduce the alternator life.
www.autozone.com has a manual specific to your car free
online. It should have directions similar to Remco's for
checking the battery and charging system, which should be
like the following, on page 10, for a 91 Accord.
Thanks again for all the advice...
I measured the voltage across the battery with the car started and it
measures about 15v. With the car turned off it measures about 10v and
just slightly under that when the headlights are turned off. I did
notice some corrosion around the positive terminal so cleaned all of
that up. However, after driving the car around for a bit to get it
good and charged it still won't start when I turn off the engine. I
just get what amounts to a repeated "clicking" noise. Is this the sign
of a bad starter?
Also, I can't verify the age or milage of the battery. However, I have
jump started the car many times (20+) over the last couple of months.
That 'turned off' voltage sucks eggs. Replace this battery.
However, I have
That sucks scrambled eggs. Replace the battery. Report back.
Interstate is a fine brand and may be what Honda is
currently using. My dealer's prices are /very/ competitive
with places like Firestone for Interstate batteries. (I
sense a trend in this direction for all Honda parts, as a
matter of fact. Internet competition may be working!)
IIRC, a few months ago my dealer wanted $65 for an
interstate battery with a five or seven year guarantee. Very
good price for what's said to be a very good battery. (My 91
Civic's latest is an Interstate, for which I paid 83
something *&^% dollars at Firestone 1.5 years ago.)
I agree that the battery looks bad but there is another remote
You should have a lot more than 10V on the battery with the car off off
unless something is drawing some major current. That would be almost
hard to believe, but let's make sure:
To alleviate that as a possibility, first put on some safety glasses -
you don't want to get hurt.
You won't get electrocuted or anything, but I am just afraid that if it
indeed draws that much current, it will arc big time. Arcing can cause
hot bits of metal to spark off the connector and you don't want that
hitting your eyes.
Again, this is an unlikely scenario but better safe than sorry.
Tun the car a little while, just enough to slightly charge the battery.
Then shut it off.
Very quickly disconnect your battery and measure the voltage (quickly,
because we want to see if that battery retained a charge). It should be
12V or so. Even a bad battery may show 12V without any load on it.
If you see a nice big arc (you'll know what this looks like), an
appreciable amount of current is being drawn. That means something in
your car is not turning off, drawing a lot of current. The battery is
most likely not the primary problem. It may still need to be replaced
after you fix your problem because they do not like to be totally
If you don't see an arc, nothing is being drawn so your battery is most
Report back with your findings.
Have you ever seen a battery blow up? I have and just in this situation.
With the lack of knowledge shown take it to a mechanic who knows what he is
doing and have it repaired correctly. Battery acid in the face is not
pleasant and pulling a cable while it drawing excessive current will do just
that. Gas is generated and the spark will cause to explode. ....
Thanks everyone for the help. I jumped the car and took it over to an
AutoZone. They ran a test and the battery did come up bad this go
around. Previously, I had the battery tested at a Walmart and an
O'Reilly and both times the battery came up fine. But after testing it
myslef today based on advice from here it did seem that the voltage was
low. At any rate, after I put in the new battery it started right up.
However, I've replaced the battery before in this car <never with a new
one> and evnetually it would fail me. So, this battery is brand new
and I will keep an eye on the problem and let you all know if I have
Thanks again for everyone's help. Time now to head back up to college.
I presume the alternator warning light on the dash has never
come on in all this, or you would have mentioned it.
I don't know what you mean by "eventually," but I wouldn't
dismiss the problem being simply your choice of used
batteries and non-OEM ones.
The new battery might do the trick, but I agree you are
right to remain vigilant. You might want to check its
voltage, running w/o headlights, running w/headlights, and
off and monitor this a while. It's a simple enough check
that, while not conclusive, might tell you something.
Also, ISTM all that running the batteries down to low charge
may have taken a toll on the alternator, so be prepared for
that being a problem soon.
You really do want to keep those battery terminals clean.
They're worth checking at least once a month for the
immediate future. I just use baking soda and water. Some
here recommend a certain sealant, whose name or description
I don't remember, too. Ask at Autozone, and they'll probably
Jumping in here... if you're reading 15+ volts across the battery with
the car running, it's very possible that your voltage regulator is bad
and the overvoltage is killing your batteries over time - alternator
output should normally not be much over 14.5V with engine running and no
load (no lights, wipers, blower, etc.).
The regulator is, I believe, internal to the alternator, so you're
looking at needing to remove and rebuild or replace the alternator.
Have Autozone do a proper alternator test to make sure there's no other
problems, before you end up needing to replace your new battery again.
I am merely suggesting disconnecting/reconnecting it. I am not saying
it definitely is a possibility, just that it is a _remote_ possibility.
Disconnecting it is a good thing, just to see what state the battery is
Notice that Elle omits this very revealing information,
The "10 V" that cause sucking eggs are in disagreement
with a battery test, so the important question is,
"Where exactly was the voltage measured?" The inquirer,
we can tell, is ignorant about matters electricity. He
Add to this the the other information the inquirer had
provided, like both the battery and the alternator
tested fine, and the proper diagnosis is "weak
connection." The probability is very high that cleaning
the terminal and the clamp (this involves taking off
the clamp and, if necessary, removing corrosion from
the contact surfaces) would have solved the problem,
and that a new battery was unneeded.
It is disturbing that experts find it easier to suggest
replacing parts instead of using their brains to find
the causes of the problems.
To make connection problems less likely, particularly
at the battery terminals, apply vaseline liberally. And
make sure that the clamp grips the terminal tightly -
if it is too large thin wires from a multistrand cable
can be inserted between terminal and clamp.
Eehhhh... Not sure where this second guessing way after the fact is
coming from because Elle was right: The guy went to autozone and they
found the battery bad...
His battery was replaced a while ago with another old battery. They
don't last forever.
Also he checked the battery terminal but let's analyze what you said:
the car was not running. Nothing was on and he measured 10V.
Draw yourself a schematic with a battery and a resistor attached to the
positive of the battery, equivalent of having a bad contact.
The other side of the resistor is not connected to anything --
remember: nothing is running.
You say that it totally depends on where you hook your meter up to see
the right voltage. That is simply not true in a static circuit (as in
no current running):
Envision hooking a voltmeter across the battery terminal. You'll
measure the potential of the battery.
Now think what you'll measure if you hook that very same voltmeter
across that open resistor and ground. You'll still measure very close
to the potential of the battery. This is because that bad contact
resistance is relatively small by comparison of the resistance of the
meter (which is ideally infinite, I'll grant you that it usually
something in the order of a 100K or more, even on a cheap meter).
So to drop 2V across the bad contact, the resistance of that contact
would need to be about 20K. Sorry, but NFW that you'll ever see 20K
So first think, check your facts, then type (And critique after the
fact is just not useful)
As Remco details, Elle got it right.
Any battery that is charging at 15 volts and after charging reads 10 volts
under load is bad... poor connections or not. As Remco pointed out in an
earlier post, the caveat is that there really could be a significant load,
and that slim possibility had to be ruled out to be iron-clad certain.
Btw, in your case that clicking is most likely due to the battery's
voltage being too low.
You turn the key, the relay clicks on, the starter draws current
bringing the voltage even lower causing the relay to unclick. The
current draw drops causing the voltage to rise, the relay clicks, etc,
Your starter is most likely just fine.
Your starter -could- have eroded contacts inside the solenoid.
Some Honda starters solenoids can be replaced,others(Denso) require
replacing the entire starter,or replacing the contacts.
(www.nationsauto.com is where I got the contact parts kit I used on my
Integra Denso starter)
You jump because the battery is dead, right? No point jumping a full
battery. It wouldn't do anything anyway, as the jumper and jumpee are
at same voltage potential. If they are at a different potential, it is
The jumping is not so much the problem, but the fact that the battery
was allowed to discharge to near dead and I am sure that's what Elle
A deep discharge causes the internal resistance of a a regular lead
acid battery to creep up. Do this a couple of times and you'll loose
serious capability. That is inherent of the cells used.
After one deep discharge one might permanently loose as much as 5-10
percent of capacity on some cells.(Capacity, as in the amount of
current it can deliver, both peak and constant)
Just using simple high school physics:
Since your internal resistance crept up, yet your output voltage
remains pretty much the same, the capacity goes down.
(E=IR -> E(constant) = I(high) * R(pretty low) = I(lower than high) *
R (crept up)
This is also why a battery like this will not 'take' a charge. You
might put a charger on a totally dead battery to find that the charger
indicates 100 percent charged in less than 10 minutes. Same reason.
If you need a battery to run til near empty, one should get a battery
tolerant to deep discharges. Commonly used on boats, etc.
That was implied, but I wasn't particularly thinking that
it's really the fact that the battery has gone to 'deep
discharge' that causes its life to shorten. So you're "on
the money" here, Remco.
I thought you were right with this assertion (and you are),
but I must say I had a heckuva time confirming it. There's
plenty of chatter about how battery plates/grids corrode
over time. But finding a site that says, 'This corrosion
increases the battery internal resistance' (something
somewhat intuitive but not spot on definite to me) took
awhile. I finally found this:
"The internal resistance of Lead-acid batteries is very low.
The battery responds well to short current bursts but has
difficulty providing a sustained high load. Over time, the
internal resistance increases through sulfation and grid
I also saw at one of the battery sites to which Tegger's
site links that keeping a battery below about 90% full
charge on a regular basis will reduce its life
exponentially. This implies that doing anything that results
in a run-down car battery often, and so requiring frequent
jumps by anyone mortal, will way reduce the battery's life.
I agree with the essence of the rest of your analysis,
I did some research on a battery related problem we were having at a
time, actually something totally unrelated to cars. (do R&D in real
life - the car thing is just a hobby).
I'd have to look through my notes to be absolutely accurate, but do
remember that the exponential nature of the damage done was true in my
The stuff I was tinkering with at that time was better than off the
shelf commercial junk and found about a 5-10 percent drop in capacity
in some cells after the first deep discharge. Being just commercial
stuff, car batteries may be a lot worse but are certainly not much
Combine that, a cold morning and your car stands a snowballs chance in
hell to start in the morning.
If you have jump started your battery a bunch of times, start thinking
about a new battery.
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