Full Battery, Still No Start

[VenomUK]

Not long ago the OEM battery got old and would wet itself, around the house I had a spare Optima Red Top battery from a previous project. It's quite large but fitted in the space of the old battery and is more than enough to crank the engine over. For a period of time, all had been fine and good without any issues. It spends its life on a Ctek 5.0 charger but recently the car developed an issue where checking the battery with a multimeter the battery is fine and healthy off charge has 13.x across the terminals. If I got to turn the key the car just clicks as if the battery is flat. If I connect the jumper pack and turn the key it fires first time. once running and checking the terminals I have a good strong charge going to the battery.

So I can't find any faults with the battery or charging system it just seems it doesn't want to start off the battery alone? I did recently have a random issue where the car started on its own and drove it to the garage, then come to start again and no matter how I jumped it, it didn't want to start which turned out to be the blue 15 amp fuse needed a good clean and bang it started off the battery pack again.

Now it seems the car can come off charge and won't start but if I pop the booster on it it will start first time. I have taken the negative off and tested for a drain and had a reading of below 0.46 which then went down and settled at 0.04 but it was still below .50 which what I could find is perfectly fine?

Any suggestions where to look now or what it could be, please?

 

[botfch]

When you jump it are you connecting to both terminals or are you putting the negative on the engine block?

 

[VenomUK]

When you jump it are you connecting to both terminals or are you putting the negative on the engine block?

Both terminals

 

[botfch]

Hmm does sound like the battery hasn’t got enough amperage to crank but unless you can get it to crank you won’t be able to test it.

Do you have a spare battery you can borrow?

Initially I was going to suggest a bad earth so you could check out the earth strap to the gearbox but the jump pack suggests that’s fine.

 

[gambit]

Optima could be dead, they do end up dying.

 

[Brigsy]

It sounds like the battery has died. Had similar issue on the mrs blue meg, sat on trickle all winter, started twice when we got it out the garage and flat.

 

[VenomUK]

I'm thinking it could be dead then. It did sit in the garage for a long time and I done as the website suggested in reviving a dead battery but it seems to keep happening so I'm guessing its kicked the bucket. I tried sticking it on an old school charger for a good 24 hrs to see if that would help as I know with smart chargers the ampage can be too low for a smart charger to recognise it's connected up but that hasn't resolved it.

 

[Usr117063]

This is the problem with mine. I had to jump start it the other day even though it had started just fine not long before that. I left it a while, came back to and it starts right up. More than once this has happened now.