Battery cables

Tom P

Petty Officer 2nd Class
Joined
Oct 1, 2006
Messages
140
I have a 1985 Merc500, 50hp that could use new battery cables. (From battery to motor) At work they but in a new UPS for computer equipment. But the power cables that came with the unit were to short. So the electricians made their own. I have the old cables. The numbering on the cables says:

E175040(L) 2 AWG (33.62 mm 2) (UL) MTW OR THHW OR BC-5W2 OR AWM 1232/1283/1346 600V OR 102269 1000V VW-1 --- 182067 (L) CSA TEW 105C 600V FT1 OR AWM I A/B 105C 600V FT-1 W75 O --- SAE J1127 TYPE SGT

Can I use these as battery cables?

Thanks,

Tom
 

Fuzzytbay

Chief Petty Officer
Joined
Jun 6, 2008
Messages
557
Re: Battery cables

They are 2 gauge american wire standard, given the current draw is limited to starting only, they should work. For a test, use a full charged battery, rested for 24 hours after charging. It should ready 12.6 volts, now hook it up to the motor, put the DVM on the starter, and ground, have someone crank it over.
The voltage drop should not be lower than .4 volts (ie 12.6 drops to 12.2). If the voltage drops more than that, either the starter needs a rebuild, or the cables cannot handel the current draw, from your particular starter.
 

j_martin

Admiral
Joined
Sep 22, 2006
Messages
7,474
Re: Battery cables

Never mind Fuzzy. The battery would drop in voltage as they are rated to supply starting current at considerably below 12 volts.

If you insist on testing, put your meter on both ends of one of the cable. Should drop 0.2V or less when cranking. I'd just put em in and run em.

hope it helps
John
 

Tom P

Petty Officer 2nd Class
Joined
Oct 1, 2006
Messages
140
Re: Battery cables

It sounds like at worst, worst worst case, this may not be 100% perfect. My 1985 motor may score a 95% on the starting test. That's better than I'm getting right now. I'm going to go for it.

Thanks,

Tom
 

j_martin

Admiral
Joined
Sep 22, 2006
Messages
7,474
Re: Battery cables

I just did the math on 2 gauge wire. With 10 feet total cable you would have 0.1V total drop per 100 amps draw. Your starter should draw 100 - 125 amps.

It wouldn't surprise me to see a perfectly good battery drop to 10.5 volts at 125 amps.

Put em in.
John
 

Tom P

Petty Officer 2nd Class
Joined
Oct 1, 2006
Messages
140

j_martin

Admiral
Joined
Sep 22, 2006
Messages
7,474
Re: Battery cables

After you mentioned that the cables are 2 guage I check westmarine's site to see what they sold.

http://www.westmarine.com/webapp/wc...=true&storeNum=5002&subdeptNum=9&classNum=297

Besides length, mine are 8', what's the difference between their 2awg cables($70 each) and my 2 awg cables (free)?

Or

http://www.iboats.com/2_Gauge_72_Red/dm/*******.070904258--**********.334918569--view_id.69096

Iboats for $28.22?

Tom

Possibly only the sealing on the connectors. It's nothing a little liquid electrical tape, or adhesive lined shrink tube won't fix.

As I said, put them in.
John
 
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