Did a stupid thing and ran down the battery. Now it's on a 12V 2/6
amp charger. Every two hrs., I remove the charger from the AC source,
negative ground clamp, and positive clamp and attempt to crank the
Is is necessary for safety purposes to disable the charger, or can I
leave it connected while testing to see if the engine cranks over?
Unless the charger is specifically designed to handle 'boost'
voltages, the current drawn by starting will ruin the diodes. For a
small trickle charger, the few amps provided over the battery capacity
would have no noticeable effect on starting results, so the sensible
thing is disconnect. You may also be surprised to find that
recommendation in your owners manual.
Chuckle. Living alone, and for several years only had one car. Best
forty bucks I ever spent when living in the apartments was that Shumaker
(sp?) boost charger and long extension cord. Paid for itself the first
time I didn't have to call a tow truck. Haven't used it in years, now
that I park inside my own damn garage, and have 2 vastly more reliable
cars. But keeping it just in case.
And what's an owner's manual? One of them paper book things? They never
seem to be included at the auctions and yard sales....
I also find a car battery charger to be useful.
The "jumper packs" with the internal battery are useful, also. I've
got one in each vehicle, and have used them several times. I bought a
22 amp jumper pack from Harbor Freight, one time. Sixty bucks. It
didn't work the once I needed it. Took it back. Bought a 17 amp one
from NAPA auto supply. Hundred bucks, but at least it does the job.
On Sat, 14 Aug 2010 19:31:36 GMT, Home@Home. (* US *) wrote:
Look at the two answers above from HeyBub and Colbyt. This is a text
book example of why you don't ask an automotive related question in
this group. One would think with a name of alt.home.repai it would be
obvious but obviously not.
Depends on whether alt.home.repair means "repairing THE home" or "repairing
That said, where else would one go for advice on shearing sheep, folding
paper airplanes, or framing a marriage proposal (I like "Will you be my
While I have no desire to start a flame war, I do feel the need to point out
that some of us can read and do read the manuals that came with various
For that reason I will stand by the initial answer I posted to OP's
question. For you I suggest RTFM for charging instructions included with
most chargers and the warnings that are included in the better written
The point I was trying to make is that your answer "Yes you should
always disconnect it while trying to start" and Heybub's answer Leave
it connected. The extra boost it provides may enable you to start your
machine before the battery is fully charged" were diametrically
opposed. However, in this case either answer was acceptable.
As far as RTFM I fully agree and have recommended that solution to
many questions here. If that was the first thing subscribers here did
the number of posts would probably reduce by 75% or more.
Have a good day.
RTFM only works if you HAVE the Fine Manual. For us 2nd or 3rd or Nth
owners of equipment, that is seldom the case. Not all manufacturers are
real good about putting them on their web sites, especially for older stuff.
Doesn't hurt the charger to leave it on but by all means let it charge
for 24 hours. If the battery is viable good. If not it may start after 24
hours but not after it sits for 3 or 4 days. I just replaced the 300 CCA
battery on my Deere 155. Would crank fine unless it sat for 3 days.
The battery was 10 years old.
Many of these trickle chargers are designed to be left connected to
batteries. It certainly won't hurt it. Every machine I have, has an onboard
trickle charger, this way if a machine is not used for months, the battery
doesn't die. They don't charge very rapidly, so it'll need a good 8 hrs of
more to fully charge it, if the battery is in good condition.
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