Battery drain

Al2O3 · Apr 8, 2022

Handbag said:
So never resolved this issue so any advice welcome. New alternator fitted kicking out over 13v when revving so working fine. Battery is new and is charging when engine running with volt meter. Charged battery cranks over fine. Go for a run battery will drain so it won’t crank over. Sometimes if I leave it for 10 mins or so it will crank over but labourer. I’ve no idea what’s going on. Checked all earth straps too

Have you tried putting your multi-meter in series on the current setting to see what the current draw is when the engine is off? Take one of the cables off the battery and connect the meter in series there. Anything over about 100mA and you have a current drain that you need to investigate.
To be honest, yours sounds like it's a dodgy earth or starter connection as the fellas are helping you investigate above.

kermit_rr · Apr 8, 2022

One of my better purchases was a clamp meter. It's only good to the nearest tenth of an amp but you can see if your alternator is charging your battery or not, or if there is a drain that needs investigating further.

Mine measures 0.1 A to 200A DC, so happily works on my 150A alternator, very useful tool and is a normal multi meter too

Handbag · Apr 9, 2022

So put volt meter on terminals 11.90 fired it up and slow to crank, terminals showing 11.90 revved it up and terminals jumped to 14.40 with alternator kicking out about the same. On tick over terminals showing 14.40. Switches everything on lights heater rear window de-mist terminals showing 14.20. So alternator working. Killed the engine after about 10 mins cranked over quicker as clearly putting charge into the battery. Went for a run, pulled over with engine still running terminals showing 12. Returned home terminals showing 11.90 killed the engine then cranked over again. Terminals showing 11.90. Revved the engine shot up to 14.40. Kept volt meter connected and went for another run. 14.40 shown on the journey. Got back home put everything on 14.20 then back up to 14.40. Killed the engine then cranked over quickly no problem. Showing 11.90 until revved then back up to 14.40?????? Any ideas?

kermit_rr · Apr 9, 2022

Handbag said:
So put volt meter on terminals 11.90 fired it up and slow to crank, terminals showing 11.90 revved it up and terminals jumped to 14.40 with alternator kicking out about the same. On tick over terminals showing 14.40. Switches everything on lights heater rear window de-mist terminals showing 14.20. So alternator working. Killed the engine after about 10 mins cranked over quicker as clearly putting charge into the battery. Went for a run, pulled over with engine still running terminals showing 12. Returned home terminals showing 11.90 killed the engine then cranked over again. Terminals showing 11.90. Revved the engine shot up to 14.40. Kept volt meter connected and went for another run. 14.40 shown on the journey. Got back home put everything on 14.20 then back up to 14.40. Killed the engine then cranked over quickly no problem. Showing 11.90 until revved then back up to 14.40?????? Any ideas?

11.9 is a flat battery, put it on charge overnight, take it off charge, then leave for an hour and check the voltage again. It should be >12.5v

It sounds like your alternator is faulty, but it could be a wiring problem too. When the engine is idling and you read 11.9, is the charge warning light lit on the dash? Do you read a voltage at the small connector on the alternator (other end of the dash light)?

Handbag · Apr 9, 2022

kermit_rr said:
11.9 is a flat battery, put it on charge overnight, take it off charge, then leave for an hour and check the voltage again. It should be >12.5v

It sounds like your alternator is faulty, but it could be a wiring problem too. When the engine is idling and you read 11.9, is the charge warning light lit on the dash? Do you read a voltage at the small connector on the alternator (other end of the dash light)?

Alternator is brand new and the old one was no old but thought I would swap out anyway. Getting 14v plus at alternator and 14.40 at terminals when running correctly. No battery charge warning light coming on

kermit_rr · Apr 9, 2022

Does the light come on with the ignition on, with your oil light etc?
If not then you need to get that sorted first

Battery drain

Al2O3

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kermit_rr

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Handbag

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kermit_rr

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Handbag

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kermit_rr

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