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SLK230 "Flat" Battery

Discussion in 'Electrics, Vacuum, Ignition and ECU' started by mark999, Dec 15, 2012.

  1. mark999

    mark999 Senior Member

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    The inevitable happened, a few days of non use over in the recent cold weather and the SLK wouldn't turn over. After removing the battery I discovered that it is a 55ah Toyota one, and it wasn't particularly discharged.
    The replacement batteries on ECP are at least 70ah.
    May be worth checking if your having battery problems.

    Mark
     
  2. television

    television Always remembered RIP

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    Your Mercedes:
    2002 SL500, 216 CL500, all fully loaded
    Yes the ECP batteries are very good prices, have not seen batteries that cheap for a long time
     
  3. OP
    mark999

    mark999 Senior Member

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    Just ordered the Bosch with 5 years warranty from carparts4less at £74. A touch cheaper than ECP. Their website is almost identical to ECP.

    Mark.
     
  4. television

    television Always remembered RIP

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    Your Mercedes:
    2002 SL500, 216 CL500, all fully loaded
    It is the same company ;):D
     
  5. OP
    mark999

    mark999 Senior Member

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    Well what a load of hassle. Turned out that the Bosch battery with 5 years warranty is too tall for the clamp and would have the terminals too close to the bonnet. A closer look at the website gives the height as 190mm. Carparts4less have eventually agreed to take the battery back, so I'm looking for another battery. Any recommendations?
    Cheers,
    Mark
     
  6. television

    television Always remembered RIP

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    Your Mercedes:
    2002 SL500, 216 CL500, all fully loaded
    There are motor factors in every town that supply the trade, you can buy at trade prices from them,,, look in yellow pages
     
  7. cleverdicky

    cleverdicky Senior Member

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    Your Mercedes:
    MB
    Found mine exactly the same and after a few weeks little use.
    Went to buy one last week but after a jump from the booster it was fine.
    Until today.
    So decided to unscrew the bottle tops and check the water.
    A bit slap dash pourin it in, but given the conditions...
    I still reckon a good pint and a bit went in :shock:

    We'll see how it goes ;)
    But perhaps yours is the same ??
     
  8. OP
    mark999

    mark999 Senior Member

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    I'm pretty sure the battery is ok itself as it isn't particularly discharged when i put it on the charger. Its actually a Toyota 55ah battery that is fitted, the replacemeny ones I have looked up seem to have a min of 70ah.

    Mark.
     
  9. television

    television Always remembered RIP

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    Your Mercedes:
    2002 SL500, 216 CL500, all fully loaded
    55 amp is just too small
     
  10. cleverdicky

    cleverdicky Senior Member

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    MB
    I nearly asked then if yours was a diesel :shock:

    ha, ha, ha, ha, ha, ha, ha, ha, ha, ha, ha, ha, ha, ha, ha, ha, :D
     
    Last edited: Jan 24, 2013
  11. jay63

    jay63 New Member

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    Your Mercedes:
    SLK 2000 230
    hi,just had same issue with my slk. battery flat as a you know what even though it was a brand new AA one only fit last october. when checked it had totally drained itself and this they stated was due to me not having run it for about 4 weeks.thankfully the weather is a bit better now so i can take it out a more,
     
  12. television

    television Always remembered RIP

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    Your Mercedes:
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    Batteries are not what they used to be,,,you could leave the older ones for months and they would recharge and be perfectly OK,,, with many modern types if the are left flat for just one day that is the end of the battery.


    All made worse by the cars modern circuitry where they need to go to sleep and pull quite high currents when doing so
     
  13. Still Learning

    Still Learning Senior Member

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    Newport Pagnell
    Your Mercedes:
    SL350 2007 gone. Porsche Boxster 2011
    Most car batteries are a lead-acid configuration and there are two important factors when choosing the right one.

    1. Capacity (as already stated), measured in amp-hours. If a battery can supply 1-amp for 50-hours it is defined as a 50 amp-hour battery.

    2. Internal resistance, also known as 'cold cranking current'. This is the ability of the battery to supply a burst of current without a significant drop in voltage. It is measured in amps, and the higher the better.

    It is possible for a battery with a low capacity to exhibit a higher cold cranking current than a battery with a higher capacity. For this reason a battery should not be chosen on capacity alone.

    Large diesel engines require a cold start current in the order of 200-300 amps and may require the battery to sustain this for 5-10 seconds over multiple attempts before the alternator begins to supply a recharge current.

    The science does start to get complex when temperature and diminished AH capacity ratings due to higher discharge currents are taken into account.

    If the weight isn't important to you, find the biggest AH capacity battery that will fit into the space, compare the cold cranking current with a few similar ones, and buy the one with the highest figure (and a good guarantee).
     
  14. brick10

    brick10 Guest

    Hi, i charge mine about twice a week using a c-tek battery
    charger as it does not get used that much.
     
  15. Still Learning

    Still Learning Senior Member

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    The C-Tek charger type can be particularly beneficial since it provides current pulses which help to dislodge deposits on the lead plates within the battery.

    If these deposits build up (they are promoted when a battery is left in a discharged state), they reduce the surface area of the lead, thus increasing the internal resistance. This directly affects the cranking capacity.
     
    Last edited: Feb 20, 2013
  16. moosehead

    moosehead Senior Member

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    Your Mercedes:
    C230/2005/2.5L Avantgarde SE Sport Pack Estate, SLK230/1999 and Volvo XC60/2017 AWD
    I had to fit a new battery to the wife's SLK a few years ago. Looking at the invoice it was an 096 Varta (the original MB battery was also made by Varta). The 096 fitting should be common to all manufacturers. I wouldn't be surprised if Bosch, Varta, etc. are all made by the same company. I bought mine from a company called Tayna. Excellent service and prices (at the time).
     
  17. television

    television Always remembered RIP

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    Your Mercedes:
    2002 SL500, 216 CL500, all fully loaded
    Yes Badge engineering is more common than we think :D
     
  18. brandwooddixon

    brandwooddixon Senior Member

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    Your Mercedes:
    CL500 Bluefficency 2012
    Never discount asking at your local dealer.
    The only time that I've replaced a battery (on my old E430) the MB dealership was the cheapest, by quite a margin.
    They also disposed of my old one as well (I changed it on their forecourt!).
     

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