healeys
[Top] [All Lists]

Re: [Healeys] Fw: volt drop

To: Richard Ewald <richard.ewald@gmail.com>, gardner5@comcast.net
Subject: Re: [Healeys] Fw: volt drop
From: John Harper <ah@jharper.demon.co.uk>
Date: Mon, 8 Aug 2011 20:46:35 +0100
Joel

A larger diameter cable will do no harm and perhaps give the starter a 
little more 'sparkle' but the original cable to the correct 
specification with good terminations is quite adequate.

2 volts drop is not that great. Bear in mind that the official test 
specification for 'our' M45G starter is

Torque at 1000 r.p.m.: 15.5 lb.ft with 570 amp at 8.8 terminal voltage

Lock Torque 32.5 lb.-ft with 900 amps 6.4 terminal voltage.

This with fully charged 115 amp.hr battery at 10-hour rate.

So taking the first 1000 r.p.m. as being a typical starting figure we 
have about 4 volts drop and this with short test leads used on the rig 
and a good high capacity battery.

It is more likely that your battery has an increased internal resistance 
due to age etc.

Before changing anything else I would try an alternative battery.

Regards
>Battery cables are the exception to the rule that voltage drops are connection
>issues. Corrosion can grow inside the cables and cause a no start.
>A 2 volt drop is world class. Spec is no more than 0.3V.
>Bigger cables can't hurt, but a new cable of the correct gauge should be just
>fine.
>Rick
>
>Sent from my iPhone
>
>On Aug 8, 2011, at 10:01, "Tom McCay - Classic-Car-World Ltd"
><enquiries@classic-car-world.co.uk> wrote:
>
>> Voltage drop is usually associated with high resistance joints rather than
>the cable itself. Have you checked and cleaned all of the connections to the
>battery, starter solenoid etc? Dirty or loose connections would give the same
>symptoms.
>>
>> Kindest Regards
>>
>> Tom
>> Tom McCay - Director, CCW-Tools, a division of Classic-Car-World Ltd, 32
>> Washingborough Road, Heighington, Lincoln, LN4 1RE. 01522 888178 (Tel) 0870
>> 705 9115 (fax) enquiries@ccw-tools.com  www.ccw-tools.com
>>
>> Registered address: 32 Washingborough Road, Heighington, Lincoln, LN4 1RE.
>> Classic-Car-World Limited is a company registered in England and Wales with
>> company number 3930761.  VAT registration number: 755 7630 05
>>
>>> ----- Original Message -----
>>>> From: gardner5@comcast.net
>>>> To: "Jean Caron" <vintage_roadster_restoration@hotmail.com>
>>>> Cc: healeys@autox.team.net
>>>> Sent: Monday, August 8, 2011 7:43:19 AM
>>>> Subject: [Healeys] volt drop
>>>>
>>>> Have a 2 volt- drop detected between battery and starter, so cranking is
>>>> weak.B I'd thought that I'd already eliminated grounding etc. through
>visual
>>>> investigation , so I figured it that it was the starter armature and
>therefore
>>>> had the starter rebuilt.B Installed the rebuilt starter, and still have a
>2
>>>> volt-drop.B Now I'm considering replacing the cable from the battery to
>the
>>>> starter with a larger diameter.B Any ideas?
>>>>
>>>>
>>>>
>>>> Joel
>>>>
>>>> BN2
>>>> _______________________________________________
>>>> Healeys@autox.team.net
>>>> Donate: http://www.team.net/donate.html
>>>> Suggested annual donation  $12.75
>>>> Archive: http://www.team.net/archive
>>>> Forums: http://www.team.net/forums
>>>> Unsubscribe/Manage:
>http://autox.team.net/mailman/options/healeys/enquiries@classic-car-world.co.
>uk
>> _______________________________________________
>> Healeys@autox.team.net
>> Donate: http://www.team.net/donate.html
>> Suggested annual donation  $12.75
>> Archive: http://www.team.net/archive
>> Forums: http://www.team.net/forums
>> Unsubscribe/Manage:
>http://autox.team.net/mailman/options/healeys/richard.ewald@gmail.com
>_______________________________________________
>Healeys@autox.team.net
>Donate: http://www.team.net/donate.html
>Suggested annual donation  $12.75
>Archive: http://www.team.net/archive
>Forums: http://www.team.net/forums
>Unsubscribe/Manage: 
>http://autox.team.net/mailman/options/healeys/ah@jharper.demon.co.uk

-- 
John Harper
_______________________________________________
Healeys@autox.team.net
Donate: http://www.team.net/donate.html
Suggested annual donation  $12.75
Archive: http://www.team.net/archive
Forums: http://www.team.net/forums

<Prev in Thread] Current Thread [Next in Thread>