paul7 Posted February 19, 2018 Report Share Posted February 19, 2018 1st can I say sorry its fir my MGA not the Triumph. Im replacing the twin 6v batteries with a single 12v (50ah 480cca) Ive just received the new leads and they look a little smaller than the old originals. They are rated at 110amp 16mmsq. Im told they are suitable but would like an expert opinion please. Regards Paul Quote Link to post Share on other sites
RogerH Posted February 19, 2018 Report Share Posted February 19, 2018 Hi Paul, this is what Vehicle & wiring Products have http://www.vehicle-wiring-products.eu/product.php/1030/battery-starter-cable Roger Quote Link to post Share on other sites
paul7 Posted February 19, 2018 Author Report Share Posted February 19, 2018 Yes I looked on their site but Im not sure if the 110a i have is big enough. Should have gone for the 170amp? Hoped some electrical expert might know. The cable run is about 2.5 Mtrs Quote Link to post Share on other sites
Fireman049 Posted February 19, 2018 Report Share Posted February 19, 2018 Hi Paul ~ When I had my 1960 MGA 1600 Mk1 I also replaced the twin batteries with a single 12v. If I had another MGA I'd do the same again. Tom. Quote Link to post Share on other sites
RobH Posted February 19, 2018 Report Share Posted February 19, 2018 If you assume peak starter current as around 300 A , 16mm^2 cable will give a voltage drop of around 0.6v per metre. In your case that would give a loss of about a 1.5 volt on the feed (plus and an unquantifiable loss on the earth return) and of course worse if the starter takes more current than that. You might not notice anything in the summer but very cold winter starting might be affected. Quote Link to post Share on other sites
paul7 Posted February 19, 2018 Author Report Share Posted February 19, 2018 So the 170a 25sqmm cable would be better and up to the job. If so Ill just order some Quote Link to post Share on other sites
Fireman049 Posted February 19, 2018 Report Share Posted February 19, 2018 Hi Paul ~ I never had any problems after I converted to a single battery. Tom. Quote Link to post Share on other sites
RobH Posted February 19, 2018 Report Share Posted February 19, 2018 (edited) So the 170a 25sqmm cable would be better and up to the job. If so Ill just order some Not strictly necessary but I would personally for a run of that length. Edited February 19, 2018 by RobH Quote Link to post Share on other sites
paul7 Posted February 19, 2018 Author Report Share Posted February 19, 2018 I also have a battery cut out switch fitted. Would it be ok to use the 16mm 110a to connect to that. Only short lengths approach 12. I was worried the small cable might get hot? Is that the case? Quote Link to post Share on other sites
RobH Posted February 19, 2018 Report Share Posted February 19, 2018 Temperature will not really be a problem for the short time you are cranking, so using a short length of the thinner stuff should be OK. (A 300mm length will drop about 0.18 volts at 300 A and dissipate 54 watts in heat so a 5 second cranking will barely get it warm) Quote Link to post Share on other sites
paul7 Posted February 19, 2018 Author Report Share Posted February 19, 2018 Great thanks for the help. Quote Link to post Share on other sites
ianc Posted February 19, 2018 Report Share Posted February 19, 2018 I seem to recall that the MGA (and MGB) have the batteries in the floor behind the seats, which accounts for the long run. For this reason, and to allow the starter to receive as many volts as possible, especially in cold weather, the beefier cable (170A) should be used for the long run. For the very short part of the run, the 110A cable would suffice. Luckily for us, TRs have the battery very close to the starter motor. Ian Cornish Quote Link to post Share on other sites
paul7 Posted February 19, 2018 Author Report Share Posted February 19, 2018 Ian yes your right Im guessing but the leads about 2.5 mtrs Quote Link to post Share on other sites
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