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Re: Jump Start

To: Tab Julius <tab@penworks.com>
Subject: Re: Jump Start
From: "James H. Nazarian" <microdoc@apk.net>
Date: Mon, 13 Dec 1999 13:48:01 -0500
Tab,

#1 is correct.
#2 is best to connect + to + before grounding so there is no ground to complete 
a
short circuit between cars with all those clamps dangling about. Also, it is
easier to make these connections safely with an extra set of hands, but we don't
always have that luxury. The results of accidentally connecting two batteries in
series and completing a circuit is not a red hot wire, it is more like an
explosion, and a rain of sparks. I did actually witness someone do that: very
impressive pyrotechnics.  Another reason is to avoid any sparking at the battery
because there can be hydrogen gas present (it is released during the charging
process.), and a highly combustible gas it is. I've never seen or even heard of 
an
actual case of a battery exploding, but I wouldn't want to get sprayed by any
amount of sulfuric acid. It will make holes in your best work clothes, and maybe
your skin.
#3 I agree with you.
#4 I agree with you, and a big ouch to the new garage entrance.

Jim

Tab Julius wrote:

> 1) It is my understanding that you can even jump different-polarity cars as
> long as you put the negative cable on the battery terminal itself and not
> the body of the vehicle.  I confess to never having tried it myself.
>
> 2) Not to start a thread on the "Right Way to jump" (probably too late) but
> I have always jumped vehicles connecting neg-to-neg, then pos-to-pos.  I
> have seen some official instructions on a cable set indicating the opposite
> (that is, pos first), but never understood why.  By connecting the negs up
> first you ensure there's a return path for when you go to do the pos's, or
> so I've thought.  I've jumped a lot of cars this way (living in toasty New
> England) and have never had a problem, but if someone knows why pos should
> connect first, I'd like to hear it.
>
> 3) I always have the jumper running, and the jumpee of course is off, and I
> hook them up.  Depending on how drained the jumpee is, they may need to be
> hooked up only for 5 seconds to get it started, or twenty minutes if it's
> really shot.  Keep in mind to drive the jumpee for a while after (I usually
> give it a good 30 to 45 minutes) to give the alternator a chance to
> recharge the battery.
>
> 4) Also, it never hurts to own a battery charger.  I have one I paid maybe
> $35 for - don't really recall - that I had been using for my lawn mower,
> but had chance to use it on my Toyota the other day.  I had left the dome
> light on or something and had not gone near it for nearly a week (driving
> my B instead) and it was well and dead by the time I went to turn it on.
> Unfortunately, it is an automatic, and was in my garage.  Not a problem - I
> figured I'd roll it out and jump the battery with another vehicle as donor.
>  Alas, it has a safety device that precludes the transmission from being
> shifted when the engine isn't running, so I had no way to shift it from
> Park to Neutral to allow it to be pushed out of the garage (of course, it
> was in nose first).  I ended up having to use the battery charger.  The
> only other alternative would have been to borrow some Really Long jumper
> cables from my local mechanic, or to make a new entrance to the garage.
>
> - Tab
> '78B
>
> At 12:40 PM 12/13/99 -0500, James H. Nazarian wrote:
> >Hi Scott,
> >
> >Your 1976 MGB is wired "negative to ground"; so is virtually every car
> made since
> >at least 1970. If you are going to jump start from another vehicle,
> confirm that
> >both cars have their negative lead (should be black) grounded to the frame or
> >body close to the battery. If you confirm that, be certain the two cars
> are not
> >touching metal to each other, then clamp one end of your jumper cable set
> to a
> >piece of wood, again confirm that the two clamps do not touch each other.
> Take
> >the other end of the jumper cable set to the boosting battery, clamping
> first the
> >red lead to the positive battery terminal, then clamp the black lead to the
> >negative terminal or a good ground point.
> >
> >Bring the opposite end of the cable set (still clamped to the wood) to
> your MGB
> >battery; clamping first the red lead to the positive battery terminal,
> then clamp
> >the black lead to the negative terminal or a good ground point such as the
> frame
> >that holds the battery. Start the boosting car; let it run. If you are
> using a
> >light gauge jumper cable set, leave the two connected this way for 5-10
> minutes.
> >Now start the "B" as you normally would. Leave the connections on until
> the MG
> >warms up. When fairly certain that the MG will stay running, turn off the
> other
> >car and begin to disconnect the clamps in the opposite order as they were
> >connected: MG Black, clamp to wood, MG Red, clamp to wood, other car
> black, other
> >car red.
> >
> >If you are going to jump start from your battery charger, the process is
> simpler.
> >Connect the black and red leads from the charger to the MG battery
> negative and
> >positive terminals respectively. Turn on the battery charger for a 5 minute
> >charge. at the end of that time, switch over to the start position and
> start the
> >MG as usual. As soon as the MG starts, switch off the charger, and remove
> it when
> >the car is running smoothly.
> >
> >BTW if you are doing this in a garage or unclosed space, watch the
> ventilation;
> >with two cars running, you will suffocate before they do, and that's no
> fun at
> >all.
> >
> >Good Luck,
> >
> >Jim
> >
> >Scott Regel wrote:
> >
> >> Can you jump start the "B" without frying anything?  I have a battery
> charger
> >> that can jump start it, but was wondering if I would be opening a can of
> >> worms.  I've got to get a new battery, but don't have the funds until
> the end
> >> of the month and the weather has just been to nice!  TIA, also thank you
> guys
> >> for all your great help and input on this list.  Talk about a support
> group!
> >>
> >> Scott
> >> 76B
> >
> >
> >


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