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[Auto Addict]

The jump leads don't have an impact, you don't get surges as a result which will impact the ECU's, in fact modern ECUs are more robust than ever

I was going to say: Cars have contained ECUs for decades. What makes manufcaturers suddenly unable to design one that can cope with a jump start? 


I am quite prerared to believe that Mercedes can't design one that can cope with a jump start, mind.

Hence my question. 

I know for a fact they can't design a good standard seat 

Mine has two separate connection points separate to the battery for jump starting.

As regards the seating, Mrs AA who has back problems has found the seating to be the most comfortable of all the cars I have owned

[STEMO]

My arse hated my astra seats for the first month or so, so much so I was thinking of getting shut. After a while, either the seat became arse shaped or my arse became seat shaped, so all ok. 

[ronnyd]

My arse hated my astra seats for the first month or so, so much so I was thinking of getting shut. After a while, either the seat became arse shaped or my arse became seat shaped, so all ok. 

I,m finding the same thing with the Vactra C i,ve just acquired. Not so sure about going from auto to manual though.

[dave the builder]

My arse hated my astra seats for the first month or so, so much so I was thinking of getting shut. After a while, either the seat became arse shaped or my arse became seat shaped, so all ok. 

your arse  would love* an Omega seat   


*until the mechanic bends you over with the repair bill

[ronnyd]

My arse hated my astra seats for the first month or so, so much so I was thinking of getting shut. After a while, either the seat became arse shaped or my arse became seat shaped, so all ok. 

I,m finding the same thing with the Vactra C i,ve just acquired. Not so sure about going from auto to manual though.

Vectra. 

[TheBoy]

Cant you just kindly, properly trickle charge it. That's always the safest way.

Batteries don't like being left for days on end in a low state of charge, so its fair to assume the battery won't last that long now anyway.

[TheBoy]

Cant you just kindly, properly trickle charge it. That's always the safest way.

Batteries don't like being left for days on end in a low state of charge, so its fair to assume the battery won't last that long now anyway.

Which is precisely why I put electricity into the battlebus every 2-3 weeks

[Kevin Wood]

Cant you just kindly, properly trickle charge it. That's always the safest way.

Batteries don't like being left for days on end in a low state of charge, so its fair to assume the battery won't last that long now anyway.

Yep, and letting the alternator charge it at a 100 Amp rate after you've jump started it probably won't do it any favours either.
Time is clearly not an issue here so I'd just put a trickle charger across it for a couple of days and then try it.

[Andy B]

The other year when Mercedes couldn't fix the suspension on my R Class it must've had repeated starts with very little driving in between and as a result, when my car was supposedly ready for collection the battery was flat. Their mech just jumped it from a standard battery pack .... obviously using the posts under the bonnet as the battery is inaccessible under the driver's seat.

[JasonH]

I'd trickle charge it. Jump starting can definitely damage BMW's. The problem is the alternator is pretty meaty, like 170A, and electronically controlled.

For the car being started the problem occurs when you disconnect the jump leads. The load on the alternator suddenly increases massively. The voltage can spike to perhaps 18V or more, just for a moment. It depends what other consumers are on to absorb the spike. There are loads of electronic modules on these cars and some just aren't as robust as they should be. On BMW's the MULF (Bluetooth module) and glow plug controller module tend to instantly die....

You face the exact same problem if you are the car doing the jump starting - possibly worse. Here when the leads are disconnected the load on the the supplying car is suddenly a lot less than it was and the voltage spikes.

[biggriffin]

In the oldern days I was always instructed, put the headlights on to sidelight before jump starting, as this takes the spike, was also told the same by DAF and Volvo O and Scarnia.

[BazaJT]

On at least some Fords[the C-Max was particularly prone for some reason]it would blow the radio-regardless of whether it was switched on or not.

[tunnie]

Well, to my surprise it started on the button! No issues and straight into life, had aux battery warning though.

Drove fine! After Italian tune up, aux warning went out. But the battery for that is still knackered.

[aaronjb]

Modern car doesn't flatten battery when left unlike the knackered old jalopies we all run, shocker.

(Just jealous because I'm pretty sure I can stand there and watch the battery go flat in real time in the BMW..)

[Marks DTM Calib]

I'd trickle charge it. Jump starting can definitely damage BMW's. The problem is the alternator is pretty meaty, like 170A, and electronically controlled.

For the car being started the problem occurs when you disconnect the jump leads. The load on the alternator suddenly increases massively. The voltage can spike to perhaps 18V or more, just for a moment. It depends what other consumers are on to absorb the spike. There are loads of electronic modules on these cars and some just aren't as robust as they should be. On BMW's the MULF (Bluetooth module) and glow plug controller module tend to instantly die....

You face the exact same problem if you are the car doing the jump starting - possibly worse. Here when the leads are disconnected the load on the the supplying car is suddenly a lot less than it was and the voltage spikes.

Reality is that the theoretical (or poorly considered theoretical) 18V is not achievable, the battery on the supplying vehicle stops the voltage from going silly high as it takes the short term output (as it effectively tries to take a charge).

Plus automotive components are supposed to be tested to twice nominal supply for a short duration......