PeaTear Posted April 16, 2018 Report Share Posted April 16, 2018 What should the charging voltage be to the battery when the car is just idling? I've replaced the battery and just out of curiosity I checked the voltage which was reading 17 to 18 volts. Is this right for a spitfire? Link to comment Share on other sites More sharing options...
Pete Lewis Posted April 16, 2018 Report Share Posted April 16, 2018 Hi I would expect 14.7v as a max 17/18is a bit excessive, what happens if you use headlamps on ? Repeat with engine off, Pete Link to comment Share on other sites More sharing options...
Guest Posted April 17, 2018 Report Share Posted April 17, 2018 PT, Do you have an alternator or dynamo ?? As Pete has mentioned, 17 to 18 is too high. If dynamo the control box may not adjusting the current output properly and if it is an alternator the diodes may be at fault or similar within the unit. Depending on what type of control box you have (if you run a dynamo) they can be adjusted. A bit more info from you will help us to assist - hopefully !!! Regards. Richard. Link to comment Share on other sites More sharing options...
PeaTear Posted April 17, 2018 Author Report Share Posted April 17, 2018 Hi. Thanks for the replys. I'll check the voltage with lights on tonight. There is an alternator. Link to comment Share on other sites More sharing options...
Casper Posted April 17, 2018 Report Share Posted April 17, 2018 Alternator Health check Tick-over - ignition only 13 v - 13.5 v Tick-over - Headlights on 11.5 v - 12.5 v 2000 rpm - ignition only 13.5 v - 14.5 v 2000 rpm - Headlights on 13 v - 13.5 v C. 1 Link to comment Share on other sites More sharing options...
Anglefire Posted April 17, 2018 Report Share Posted April 17, 2018 17/18v is way too high - moderns often run around 15V to increase the power, but then have to be a bit clever in voltage management - my old Discovery is one such beast and when halogen bulbs were fitted, the ECU soft starts the bulbs and gradually increases the voltage so as not to shock them - you can tell if you change to Xenon headlamps (Complete unit change, not just an illegal bulb swap) and unless you change the cars configuration, the Xenon's flicker on startup because they do need more volts (about 50000) to get going before dropping back to about 15,000v) Link to comment Share on other sites More sharing options...
PeaTear Posted April 18, 2018 Author Report Share Posted April 18, 2018 For whatever reason it now reads about 14.5 volts at normal tickover and 12 with lights on. I'll keep an eye on it but hopefully all is good. Link to comment Share on other sites More sharing options...
Pete Lewis Posted April 18, 2018 Report Share Posted April 18, 2018 Depends on the regulator but if theres an open circuit , with no load they can rise to some higher uncotrolled voltages 1 Link to comment Share on other sites More sharing options...
PeaTear Posted April 27, 2018 Author Report Share Posted April 27, 2018 Back to this old nugget. Fuel and temperature gauges aren't working. Checked the voltage stabiliser on the back of the speedometer and not getting any voltage from that. Also noticed that the indicators were intermittent and when they did work on increase of engine rpm they flashed quicker. I think I have been getting a surge in voltage but no fuses have blown. So I'm thinking I'm going to need a new regulator but how do I know which one I need? There appears to be 2 types available 2 or 3 lead and 4 lead Link to comment Share on other sites More sharing options...
JohnD Posted April 27, 2018 Report Share Posted April 27, 2018 OR... Get an alternator and ditch the regulator. This excellent description is for an MGA, but same difference. http://mgaguru.com/mgtech/electric/ac101.htm JOhn Link to comment Share on other sites More sharing options...
SpitFire6 Posted April 27, 2018 Report Share Posted April 27, 2018 (edited) Hi, Across the battery while the engine car is running; you want a minimum of 13.8 and a max of 14.5 ish. 13.8 or below on full electrical load and at 2K plus would have me checking for volt drops as 13.8 and below will ensure a low capacity battery. Cheers, Iain. Edited April 27, 2018 by Spitfire6 Changed engine to car Link to comment Share on other sites More sharing options...
SpitFire6 Posted April 29, 2018 Report Share Posted April 29, 2018 Hi, Fully charged. Around 30 mins needed to bring battery up to max capacity 700 CCA +. Cheers, Iain. Link to comment Share on other sites More sharing options...
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