So here's the deal. The car is a Honda Civic with a group 51 battery
(Kirkland Signature from Costco if that helps). Every once in a while
the battery is heavily drained because a light (map light or headlamp)
was left on. I do find it annoying that there is no headlight-on
warning chime or auto-off. Sometimes it starts and sometimes it needs
a jump; a portable jump starter always does the trick. The car itself
is driven maybe a few times a month for short distances along with the
occasional long trip.

So I got a simple Schumacher Electric 1 amp, 12 V trickle charger -
the kind with thin wires and light-duty clamps coming out of a wall-
wart. It's labeled as a "manual charger" and the box/directions state
that it's suitable for charging motorcycle and other small batteries,
or for keeping auto batteries warm. I wasn't sure if I could justify
getting anything more expensive like a higher output charger or maybe
even a float charger/maintainer with a charge sensing mechanism.

So I'm wondering how safe this is with a group 51 battery, which is on
the small side for auto batteries? I realize that it's not likely to
fully charge up a depleted battery unless it's on for days at a time.
How safe is a 1 amp charge if uncontrolled like a float charger? I've
heard some concerns that it could potentially overcharge - that maybe .
25 amp is about the limit for safe trickle charging. I've heard other
comments that it's effectively a trickle charge that could safely be
left on a fully charged car battery for days if not indefinitely.

y_p_w wrote:

A manual charger that size won't do much. However if that battery has
been drawn down that many times it is on borrowed time. I would replace
the battery, then fix the warning chime. Unless that car was made before
about 84-85 it has a lights on warning chime. The other option is to
install a battery buddy. They monitor the draw on the battery and cut
the power before it gets to low to fail starting the vehicle.

--
Steve W.

A 1 amp charger can be left on for a couple days and in fact a very slow
charge is the best way to revive a completely discharged battery.
Contrary to what many people believe, completely discharging a lead acid
battery doesn't do much harm. Mostly, the damage is done when
recharging it. I think you are looking at something like 3 days to
charge a fully discharged battery with 1 amp.


-jim


y_p_w wrote:

On Jun 24, 1:32*pm, jim <"sjedgingN0Sp"@m@mwt,net> wrote:
When I use a portable jump starter I typically leave it on for a
minute or so before disconnecting it. It should definitely charge up
the jump starter's battery a bit, and I understand that it might also
reduce the initial charging current to the car's battery. I've been
told by some people that a lower initial charging current is critical
to reduce battery capacity loss.

On Jun 24, 11:22*am, "Steve W." <csr684... (AT) yahoo (DOT) com> wrote:

My 2004 Subaru Impreza WRX doesn't have a headlamp warning chime, but
it does have a headlamp auto-off feature. Same goes for some
relatives' Toyota Camry.

I did some research and I think I know what the problem is.
Apparently the driver's side door open switch can get stuck to the
closed position. I've noticed that the dome light doesn't turn on
when the driver's side door is open and it's switched to the center
(door selected) position. Apparently the headlamp-on warning or key-
in-ignition warning chimes don't activate until the driver's side door
is sensed open.

http://vtec.net/forums/one-message?message_id=833002&page_number=1

On Jun 24, 1:54*pm, y_p_w <y_... (AT) hotmail (DOT) com> wrote:
As a follow-up, I got home and checked it for this little switch. The
first thing I noticed was that all three other doors worked fine with
the dome light. Next, the little switch felt loose. I first tried
prying it back (bending it) when I then noticed that there was a
little hatch that opened to reveal the screw. The little switch was
actually not connected to the rubber/metal switch cover. I think it
was supposed to be grounded to the body via the screw, but the ground
clips on the switch were always loose (might have even been shaking
around in there never depressed).

So now when the driver's side door is open and the headlights are on,
it gives off a loud whine. Of course it doesn't do anything when the
map lights are on. :-(

"y_p_w" <y_p_w (AT) hotmail (DOT) com> wrote

Tell your wife or teenager that the next time they leave the car light on
and the battery drains, they will need to pay for a tow truck to come out
for a jump...

End of problem, no trickle charger needed...

"y_p_w" <y_p_w (AT) hotmail (DOT) com> wrote


I've heard other
of trickle chargers in the range of 1 -1.5 amps.

They might be left on charge for months ( thus making the dry charge battery
a step forward).

You have at least two or three options:
(1) Make sure all the lights and systems are off ( which sounds like it does
not work for you
and your present situation)
(2) Buy a unit which will sense your battery condition, and disconnect it
from the car's electrical
system if the battery is discharged to a low level. (Google for them. They
exist)
(3) Use the trickle charger as a matter of course. I dont like to leave a
battery a long time with
1 amp or more of charge, so I sometimes put a 12 v lamp in series with the
leads and decrease
the charge rate to a (bias level) 100-250 ma. Dead simple, and works fine.
Wattage of the
lamp determines the resistance, so you can select values to limit your
charge.

On Jun 25, 2:16*am, "Elmo P. Shagnasty" <el... (AT) nastydesigns (DOT) com>
wrote:
Turns out it did, and the advice that it should be fixed was sound.
It's a really loud continuous whine too. There would be no mistaking
that.

On Jun 25, 6:11*am, "William Munny" <w... (AT) jbigwhiskey (DOT) org> wrote:
Well - the deal is that I'd end up paying for it, and occasionally I'm
the guilty party from turning on the lights during the day (typically
for visibility in forest roads).

The map lights however are usually not my fault and typically they
only require a jump if left on overnight or for days at home.