Booster battery starter

[normanr]

Hi all

Knowing how touchy the electrics and ECU can be on our Mercs would you say this would be safe to use on my 1999 C200,I think I read somewhere on a forum about they don't recommend boost starting.

http://www.carparts-direct.co.uk/catalogues/so_booster_starter_charger.cfm

Thanks
Norman

 

[normanr]

Hi Guys

Any ideas or would you rather not commit.

Many thanks

Norman:bannana: :bannana:

 

[harveyn]

I am far from an expert, but I do recall a Merc garage saying that if you do have to use one, turn the lights on first, as it is less likely to spike the ecu. Presumably you could turn on other electrical accessories aswell.
Good luck! (Prefer a trickle charger myself)

 

[dougal74]

I heard reports that people have fried their electronics from jump or boost starting, but often wonder if that is because they have connected +ve to +ve and -ve to -ve rather than the proper mounting point for -ve.

I had some problems with my BMW (with lots of electrical gizmos) and didn't have a problem when jump starting from my wife's car. I think I would only do a boost as an absolute last resort. Preferring instead to drive something else and put the offending battery on trickle charge.

 

[Benzowner]

I am not an expert by any means, but surely if it was iffy to jump start a car, why would Mercedes put a positive terminal under the bonnet?

 

[Benzowner]

posted twice

 

[normanr]

Thanks for the reply's fellows

Very helpful, as you say geoff2 they do put the poss terminal under the bonnet,the only reason I asked is I have only just forked out for a new ECU which cost a lot of money.

I suppose to be on the save side is to ask the main stealers but thanks for all your comments.

Norman

 

[Denise]

As a result of a faulty alternator my car battery went flat a week ago - and so i called the RAC out. Chap was very helpul and knew his stuff - started and charged the battery of my car but before doing so he left the car lights on - he said some of the surge in energy/electrical spike would be dissapated by the light. he said leaving fan heater would have same effect. One other thing said, before doing any of this is that if i had a spare key, apparently on some mercs and 'flashy cars' the electrics can go bonkers and lock you out!

 

[normanr]

Hi Denise

Thank you very much for that helpfull information,this forum is very good for other members experiences of the same problems.

Many thanks to you all for taking the time to reply.

Norman

 

[zerocool]

we have seen seat modules and roof modules blown,by people jump starting mercs,its quite common on 129 models,and 203 models.
the reason merc put a positive terminal under the bonnet,is so that the battery can be charged more conveniently

 

[BTB 500]

Any kind of charger connected to the vehicle battery (or remote terminal) may push a voltage spike through the system - you are taking a gamble on how 'well behaved' the device is. The only totally safe thing to connect is an external 12V battery (which obviously can't supply more than battery voltage). Having said that, connecting a normal charger (preferably a fully automatic one - to the battery first, then switching on at the mains) is probably an acceptable risk ... I have certainly done this on my R129 a number of times without any problems.

'Boosters' are normally intended to push charge into the battery at a very high rate for a short period. This requires a high voltage across the battery terminals ... quite possibly more than the vehicle's electrics are designed to handle. I wouldn't personally let one near my car, I'd rather charge the battery more slowly from a standard charger or get the vehicle running and let it recharge normally by driving it.

 

[Parrot of Doom]

I've been told as well by my mechanic at Greenvale not to jumpstart the car - he said that I should buy special 'suppressed' leads.

I'd love to know if this was true or not. It seems very silly that Mercedes may have designed a system that could be damaged by a simple voltage spike. I keep jumpleads in the boot, but they're only standard ones.


BTW, I did recharge my battery last week after messing with the fuel system, and then running it down by continuous cranking. The battery remained connected to the car, and its obviously working fine.

 

[normanr]

By all the comments this does seem to be a bit of a grey area and not worth the risk I don't think.

The only reason I put this on the forum was my Merc before this one was a 1989 190E and if the car was left for 6 days or more the battery would run flat I found out it was the alarm draining the battery I had the option of turning it off but did not want to loose the security of it.

I bought a booster start to use on it and it worked fine untill the thing packed up so I did not bother to buy another one but it did get me out of trouble when I had the good old 190E (wished I kept it now never let me down unlike the one I have now)

As I said previously because I had to spend £1700.00 on a new ECU I did not want to take any chances on messing it up but they are convenient for a quick start if you are trying to get to work etc better than trying to put a spare battery on especialy if it is p=== down with rain

 

[BTB 500]

As I said previously because I had to spend £1700.00 on a new ECU I did not want to take any chances on messing it up but they are convenient for a quick start if you are trying to get to work etc better than trying to put a spare battery on especialy if it is p=== down with rain

Easier to just jump start from a spare battery, rather than fitting it to the car. I started my R129 several times from the spare battery for my caravan

When the battery was dying on my Sharan and I was waiting for VW to agree to replace it under warranty, I actually carried the caravan battery around in the car (and used it several times).

 

[Alps]

last time my batt went flat, luckily it was in my garage, so i attached a batt charger and left it overnight, fully charged by the morning!

 

[television]

Just to clear the issue a bit. The more modern the car,the more to go wrong as we all know.
A battery that has just been charged can have more than the nominal 12.5 volts,could be as high as 13.5, your can cream this off with say a headlamp bulb for 5 mins. the only way that a battery can charge is by putting in a higher voltage, the higher the voltage the higher the charge rate up to a max of the rated output of that charger.
Automatic chargers are not good as it will put out max voltage during the first few seconds. trickle chargers switched are the best,join up with min charge,leave it 10mins then increase to 2-4 amp (a fixed charge rate of 10% of A/H rate max can only be used on AGM batteries)
The batery charge is all lnked to Ohms law. A flat battery has a high internal ressistance and would need anything up to 20 volts, to get it to start charging.

Our cars have thing like SAM modules that are live all of the time, the Command is always active, SBC brakes are always active, add in the alarm imobiliser and it starts to add up. I still think of the poor guy who filled up with deisel, though he did not start the car,just opening the car door starts up the pumps as the car new it was going to be driven, and the damage is done, but that's something else. So just by opening the door everything comes to life,if you have a charger pumping out 15v the ECU's and SAM's do not like it, more so when you open a door for instance.

ECU's ,voltage doublers and power supplies are funny things, you can turn your TV on every day for years then,bang ! its blown, the same thing happens to PC power supplies, something has flashed over or arced, the same goes for cars. Many cars do not give a problem, late 129's never do, early always do, cars with two batteries are ok as they are linked, some of the C class and 210's can be pigs and certain procedure must be followed. Though you can use the headlights to load the cicuit when charging it is better to use heated seats and rear demisters as these are more sturdy devices.


This has given me the idea to market a device that will not hurt the car when you change or disconnect the battery.

Malcolm

 

[Howard]

I have always been told (and have experienced it myself ) that jump starting a w124 can lead to blowing the OVP relay .....

I have had to replace my OVP relay after blowing it jumping the whale once it had gone flat .....

Was advised that if i have to jump the car, to turn on everything that is electric, this softens the spike as it were ......

good luck

P.S. Television, sounds like a good plan ....

 

[normanr]

Hi Malcolm

Thanks for that information I have decided to get another battery and keep it charged I don't want to risk damaging any part of my electrics for the sake of the expence of a spare battery which is peanuts to what a repair would cost.

I don't do long journeys and with the winter here I have more chance of running the battery down.

 

[television]

I will look up the specific info for your car, can I have the first 6 numbers of vin WDB------


Malcolm

 

[normanr]

Hi Malcolm

WDB202020

Many thanks

Norman