Battery drains in an hour... - anyone else had this?

Hello,

I have a soft top O2 Jimny with a Bosch S4 battery...

Never ever had any problems starting, even at -10C, lovely sunny day on Saturday, took Jimny out... great...

Came to start it an hour later.., not enough power to turn over.. dead slow........ but no reason why it would go flat.,,had no lights on , radio goes off with ignition...... anyway charged it for 24 hours.started at 2.5 then down to only 0.5 amps after an hour so I don't even think the battery is duff.... and Jimny started fine yesterday ..... left it on drive....came back 2 hours later completely dead again...
No alternator warning lights when driving, ., even wheh not able to start, remote locking works fine... fans come on...

Anyone else experiecned similar.,..

(a) can a battery just fail like that?
(b) Any known power drains that I should investigate? How to do this?
(c) faulty solenoids / starter problems to check?


Any advice appreciated!!

Ans.

My battery went just like that charged it over night, started OK but then the next day was dead again.. Changed the battery and its been fine.

May be charge the battery test it then leave it for a day and test again?

My battery went just like that charged it over night, started OK but then the next day was dead again.. Changed the battery and its been fine.

May be charge the battery out of the jimny test it then leave it for a day and test again?

Use a volt meter to see whats happening.

1. with engine off and battery disconnected you should get around 12v

2. with battery connected and still engine off you should get around the same

3. with engine running you should get around 14v to charge the battery.

If No.1 is 10v or lower then new batt needed provided 2. and 3. are ok.

If No.2 is lower than no.1 then theres a drain on the batt somewhere (light stuck on, switch stuck, etc).

If no.3 is no change from 12v then the altenator or wiring connections are faulty

could be a faulty starter motor as that gives same symptoms as a flat battery.

If you haven't got a meter just disconnect a terminal and with the ignition off touch it against the battery if there is any noticeable spark then you have a drain.
Alternatively just change the battery as 99% that is the problem.