I have a Focus Active X EcoBlue Auto estate with a completely flat battery do to non use. I can get into the car using the key fob but when I tried to jump start it from another car, the dashboard lit up but no engine.  A neighbour has lent me a Clarke 140B batter charger but I don't want to use it until I know that I'm not in any danger of damaging any of the car's systems?  Has anyone got any advice re this please? Novice owner here trying to avoid hauler charges to the local garage! 

If it's the original battery from 2019, it would probably be at/near the end of it's useful life even in normal usage.

If it were me:

I would buy a new battery (with a higher capacity on it).

Charge it to make sure it is 100% charged.

Fit the battery and carry out a BMS (Battery Management System) reset.

I agree with the above, the original Battery will be well past its best by now.

If you are worried about the Electrics then it would be safer to disconnect the Battery before charging although if the Battery is now less than 6 volts then a lot of Chargers will not charge it  because they think it is a 6 volt Battery that you are charging.#

It may be a futile exercise anyway because if the Battery is shot it will not be able to take enough of a charge.

Most of us on here with a Mk4 Focus fit this Battery from Tanya, both the Battery and the supplier are very good.    YBX7096 Yuasa EFB Start Stop Car Battery 12V 75Ah

Will 'Crime Watch UK' return to heed both of your good advice ?

A flat battery is far more common than you might think.

Don't have nightmares, sleep well 😉

Thanks for the responses. 

I don't know whether the battery has been changed since the car was new - how do I tell?

At this point I just want to be able to start the car with a battery charger so I can get it to a garage and need to know if I can do this safely without damaging the car?

 

That's quite a different charger to the ones we generally recommend.  There is a chance of damage if you get it wrong.  Your neighbour could've helped you with it tbh.

Make sure it's on 12v setting.  Also select whether you want it to charge slowly, or to work like a jump starter so you can try to start straight away.

Connect the cables before plugging into the mains.

However, it almost certainly won't work anyway.  The battery charge needs to be at least 10.5 volts, and I suspect yours will be a lot lower than that if a jump start from another car didn't work.

7 hours ago, CWUK said:

Thanks for the responses. 

I don't know whether the battery has been changed since the car was new - how do I tell?

Post a picture of the battery.