W219 CLS 55 AMG - Should I jump starting a friends car?

[szucchet]

Hey Everyone!

A bit of a different question here, I know that best advice is to charge a dead battery on most mercedes models rather than jump starting them. However, I have a friend who's battery is dead and asked if I could help jump start his car. Obviously I would be happy to help but wary about causing damage to my cars batteries and/or electrical system.

Any advice on if I should help or is it a definite no go?

Thanks!

 

[KillerHERTZ]

I wouldn't. Risk of issues with yours.

If you absolutely have to, don't used battery terminals, use the live point under the cover in your engine bay.

 

[jdrrco]

Agree with the above. A side question. If looking to charge or regularly trickle charge due to Covid lack of use, are terminals or live point better?

 

[mersum1es]

If emergency, I would connect your battery to jumped car for a while. Battery will push some juice to dead battery, and after 5-10minutes disconnect jump leads and start the poor patient. If target battery is totally dead and cannot take any charge, this won't help of course.

 

[alabbasi]

Disconnect the battery terminals and jump away. You won't overload anything that's not connected.

 

[szucchet]

Thanks for the input! I was leaning towards no but I am definitely not going to now. Its not an emergency so definitely not worth the risk

 

[pmcgsmurf]

A bit of a different question here, I know that best advice is to charge a dead battery on most mercedes models rather than jump starting them. However, I have a friend who's battery is dead and asked if I could help jump start his car. Obviously I would be happy to help but wary about causing damage to my cars batteries and/or electrical system.

Any advice on if I should help or is it a definite no go?

It's not a definite "no go" but if you are unsure and don't how/what to check best not to chance it.

 

[pmcgsmurf]

Disconnect the battery terminals and jump away. You won't overload anything that's not connected.

Disconnect what battery terminals, connect what from what to where to "jump away"?

Best be cautious, a "dead" battery could end up best part of a dead short and many amps across booster terminals!

 

[mersum1es]

I have normal 100Ah battery fully charged in my home storage, for emergency situations of my own (and neighbours )

 

[W1ghty]

I never would on either of my cars and have refused (with the offer of other help ) a couple of times in the last 8 years of MB ownership

 

[350cls]

I'm under the thinking if it was that bad to jump a car from another car the terminals wouldn't be there at all. I've done it many times with bwm's and mb. I had to jump my own E63 6.3 today from our e320. As my battery in my 63 is the original battery. I must replace asap. Surely it's no harm to jump a car in an emergency. I'm not one for having the leads attached to the cars for long periods of time. Jump the car, leads off. Have never had any issues doing this personally.

 

[markjay]

Walk into the nearest Halfords and buy him a jump-starter for £40, give it to him as a gift. This is what I did the last time a close friend asked me to jump-start his car, and I didn't want to offend....

 

[markjay]

I'm under the thinking if it was that bad to jump a car from another car the terminals wouldn't be there at all. I've done it many times with bwm's and mb. I had to jump my own E63 6.3 today from our e320. As my battery in my 63 is the original battery. I must replace asap. Surely it's no harm to jump a car in an emergency. I'm not one for having the leads attached to the cars for long periods of time. Jump the car, leads off. Have never had any issues doing this personally.

You ate supposed to use the terminals for trickle-charging, or for jump-starting the car from an external 12V battery that is not connected to a vehicle.

Like you, over the years I have jump-started other cars from my car many times with no issue, but after reading posts here from members who fried the front SAM while jump-starting, I decided that I was lucky so far, but I shouldn't push my luck, and so I don't do that any more. Quit while you're ahead....

 

[GT3RS]

Agree with the above. A side question. If looking to charge or regularly trickle charge due to Covid lack of use, are terminals or live point better?

I trickle charge with CTEK charger every month and connect directly to battery terminals in boot. My Bosch AGM is showing as very healthy after 5 years.

 

[pmcgsmurf]

Problem is for a "flat" battery it is relatively straight forward and the donor vehicle requires little output to the flat battery.

For a dead battery though this can be a different matter and the donor could require a massive amount of current output.
If in doubt best to stay away, wouldn't be the first time I've seen folks set jump leads on fire.

 

[Deadly Dave]

RAC man told me that the 13.8v from a running engine to the dead car causes the problem. He said to turn lights on in both cars then fit cables. Turn off lights and start good car then dead car.

 

[grober]

Unless its a true emergency [ stranded in the desert/rising flood water /garage in danger of collapse ] the best help you can give your friend [and yourself] is to check out the spec of his existing flat battery then give him a lift to the nearest decent motor factors to buy a replacement battery and then help him fit it

 

[350cls]

Like said I've jumped cars from my previous cars and had jumps from other folks cars. Never had an issue. Like said I wouldn't be of the mindset to have leads attached for prolonged amounts of time to charge a flat battery.

If one was stranded, would you be of this mindset. I don't think so. Jump it, drive away

 

[Wagon]

Disconnect the battery terminals and jump away. You won't overload anything that's not connected.

This ^^ disconnect battery from your car so nothing can be damaged and then jump other car

 

[alabbasi]

This ^^ disconnect battery from your car so nothing can be damaged and then jump other car

Yep, thank you for translating. In general. jumping a car from a car is not problematic. Jumping it from one of those 240v chargers that have jump start function can cause problem. But if you disconnect the battery from your own car while it's being jumped. You can be sure that you won't damage the electrical components.