ThaiLife Posted September 4, 2011 Share Posted September 4, 2011 Over the past few weeks my Mitsubishi Triton some times has been slow in turning over the engine when starting , Ive recently replaced the battery . So Last night I went to start the vehicle and again it was a slow engine turnover , I then went to look at the battery and check if the two terminals were ok, I decided to remove the Two battery leads from the battery and clean the terminal clamp connectors, when I replaced the battery leads one by one, I noticed when I touched the ( - ) lead to the battery terminal, there was a small spark. I checked the vehicle over and there was nothing switched on and all the doors were closed. So I put back the ( - ) lead and managed to start the vehicle, I then placed my multimeter on the battery terminals , set the meter to 20V DC , with the engine idling the voltage was shown as 12.5 Volts , I then increased the engine speed and the voltage went up to a steady 14.7 Volts DC , so at first glance it seems the battery is being charged . This morning I removed one battery lead ( - ) and put my multimeter in line with the lead and the battery terminal , and set the multimeter to 10 AMPS , ( the small spark was still there when I touched the battery lead to the battery terminal. This is the reading I first got .. then after a few seconds the reading went to this .... Then finally to this ...... I have checked and cleaned the alternator connections , which all look ok. So just looking at the multimeter AMP readings , it seems there may be some sort of live connection taking power from the battery when the vehicle electrics are all off . I can't see how its normal to have even a minor discharge when the vehicle electrics are all off, or am I missing some thing ? just to add that some times the vehicle will start correctly and the engine on turning the ignition key , starts normally . any advice or suggestions please . Link to comment Share on other sites More sharing options...
transam Posted September 4, 2011 Share Posted September 4, 2011 When you turn the ignition off and lock the car the battery is not disconnected, It is still feeding interior lights and possibly other stuff. So you could have a small drain somewhere or the alternator has a slight drain. If your battery is new and the correct amperage for your ride it should read 12.5 +, with engine off and 13.5 - 14 volts when running on idle. If charge heading towards 15 volts it will cook your battery. My ride alternator shows 13.7 volts when engine running at any RPM. Link to comment Share on other sites More sharing options...
hkt83100 Posted September 4, 2011 Share Posted September 4, 2011 Possibly there are some things in your car like: - Clock - Radio on stand-by, especially one of the newer ones with theft-protection - Central lock with integrated alarm system and receiver for remote control - Navigation system on stand-by All these might drain your battery just a little bit... but it sums up. Link to comment Share on other sites More sharing options...
T_Dog Posted September 4, 2011 Share Posted September 4, 2011 I would not worry about the small current draw as a charged and working battery would handle that for weeks. I would first suspect a bad battery (even new they could be bad) and then barring that, I would have the charging system checked. The voltage measured at the battery terminals once you start your car should be more constant than what you are seeing. Link to comment Share on other sites More sharing options...
WarpSpeed Posted September 4, 2011 Share Posted September 4, 2011 The ECU in every new car uses a continual draw on the system to keep the clock and other features like digital odometers and the like accurate but the draw is minimal. Saying that at times the engine starts normally sounds to me like a potential dead spot or short in the starter solenoid that when it stops in a certain position it continues some amount of contact across the terminals and drains the battery while off. Had this happen several times before the starter will also act sluggish occasionally upon starting even after running for a while as this point in the solenoid is obviously not working properly.. My most recent instance was an older BMW I had.. Link to comment Share on other sites More sharing options...
mdechgan Posted September 4, 2011 Share Posted September 4, 2011 A little current draw with the ignition off is normal. It could be the hundreds of relays, capacitors, the ecu, interior lights, clock and/or radio. A .01 amp draw in a 70amp/hr battery will take hundreds even thousands of hours to drain. A 12.5 volt reading with the engine at idle and accessories of doen't neccessarily mean the alternator is bad or not charging the battery. It could mean the ecu senses the battery is fully charged and there is no electrical load. A hard or slow start could mean the starter needs maintenance. On my old Dmax my stater didn't fail but was slow and had very little torque, the bearing was bad and one of the carbon contacts was rusted and stuck. This was because maybe water got into the starter on my adventures through the flooded streets of Bkk. Link to comment Share on other sites More sharing options...
Tarric Posted September 4, 2011 Share Posted September 4, 2011 When you turn the ignition off and lock the car the battery is not disconnected, It is still feeding interior lights and possibly other stuff. So you could have a small drain somewhere or the alternator has a slight drain. If your battery is new and the correct amperage for your ride it should read 12.5 +, with engine off and 13.5 - 14 volts when running on idle. If charge heading towards 15 volts it will cook your battery. My ride alternator shows 13.7 volts when engine running at any RPM. Indeed.. My money in this situation would be on the voltage regulator on the alternator. If there isnt a suffecient charge going to the battery then you are going to experience symptoms like you are experiencing now and it will keep slowly killing batteries. I had the same problem with my car a couple of years ago. Link to comment Share on other sites More sharing options...
transam Posted September 4, 2011 Share Posted September 4, 2011 When you turn the ignition off and lock the car the battery is not disconnected, It is still feeding interior lights and possibly other stuff. So you could have a small drain somewhere or the alternator has a slight drain. If your battery is new and the correct amperage for your ride it should read 12.5 +, with engine off and 13.5 - 14 volts when running on idle. If charge heading towards 15 volts it will cook your battery. My ride alternator shows 13.7 volts when engine running at any RPM. Indeed.. My money in this situation would be on the voltage regulator on the alternator. If there isnt a sufficient charge going to the battery then you are going to experience symptoms like you are experiencing now and it will keep slowly killing batteries. I had the same problem with my car a couple of years ago. Yes, the regulator does a lot of work and is busy all the time. They do fail or get erratic causing lots of aggravation that the driver will know nothing about until a flat or cooked battery. Sometimes, if the regulator is over charging and cooking the battery you can smell acid in the cab. Double check that the battery is the correct amp for your ride. Diesels require mega amps on starting because of the high compression ratio. Link to comment Share on other sites More sharing options...
GamLing Posted September 5, 2011 Share Posted September 5, 2011 Have a look at this topic on ThaiVisa Mitsubishi Battery Drain Link to comment Share on other sites More sharing options...
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