battery, started, or alternator!

Hi
I have Honda Civic 2001 (59,000km). For last 2 months I drove the car
for few times (5-10) times in each sped around 10km. Last month I
started my car and I saw the battery indicator red color (the
indication the battery is in trouble), I drove the car and after I
came back home that idicator gone .. but a week after I wanted to
start my car, it did not started at all, I called for battery boost
and the guy came and saw the alternator give 15v at the begging then
13v.. he said it is may be the alternator.. Now the car is dead..
Should I change the battery?? if yes what type/model should I buy??
should I buy it from the Honda dealer or generic one is ok.. thanks a
lot.

 

Do you mean the alternator light? If so, it indicates that there is a
charging problem, not necessarily a problem with the battery.

The trick is to step on the brakes (parking brake does not count, has to
be the brake pedal) when you measure the voltage. On (most) Hondas, the
voltage regulator reduces the voltage under certain circumstances in
order to save fuel. Stepping on the brakes will defeat the voltage
reduction.

However, although 15V is technically within spec, it is very unusual for
it to be that high. The spec. is 14.5 Volts +/- 0.6V with the engine at
2000 RPM, but it is usually within 0.1V of 14.5V. Try measuring it
again, this time at 2000 RPM and with the brake pedal pressed. If the
voltage is too high, it is a bad voltage regulator (part of the
alternator assembly). If the voltage is too low it could be the voltage
regulator, alternator brushes, battery or other issues.

I bet the guy is right about the alternator but if in fact you do need a
new battery, I'd go with a generic one. Any place that sells batteries
will be able to look up what type you need. Before you install a new
battery, line up the new and the old side by side and verify that the
positive and negative terminals are in the same location. My car uses a
group 51R, but Sears once gave me a 51 (no R) instead. They are mirror
images of each other, and had I installed the 51 not realizing it was
the wrong thing, I would have fried a lot of expensive electronic
components.

 

Normally, the indicator light denotes a voltage mismatch between the
battery voltage and the charging system voltage. Please see Section 5
in the Car and Deep Cycle Battery FAQ on www.batteryfaq.org for more
information. If you need a replacement battery, please see Section
7.8.

Kindest regards,

BiLL......