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  1. G

    12 volt battery in later i3s--watch out

    I just had a visit from a friend who is a power systems engineer with our National Grid. So he certainly has more electrical knowledge than I have even if it is a kVa level. He is currently driving a hybrid Ford Kuga I believe. This has been having , in the forums, a number of issues with...
  2. G

    Charging 80 or 100%

    I have some Tesla charts that claim to show, from users, that those who only ever used supercharging had lower capacity loss over time. Data was collected by a Belgian user groups so has been somewhat challenged but I don’t see as we have an excellent heat management system (better than Tesla?)...
  3. G

    Charging 80 or 100%

    I agree 100% with the 100%. JTylee is 100% correct too. The manual was changed in February 22 to contain the ‘generic’ newer i series advice. The critical thing is that the i3 does passive top end cell balancing when charge is complete and we have no stop percentage. I.e. charge it to...
  4. G

    12 volt battery in later i3s--watch out

    Is this also because you have very moderate temperatures? We have below zero centigrade frequently in winter and folks routinely get a failure if they have left the car for a week at Christmas/end of year holidays. If the 12v is already weak I guess that can kill it off more frequently. I...
  5. G

    12 volt battery in later i3s--watch out

    Pretty sure it isn’t activating the DC-DC charger unless the car is ‘on’. Easy to leave it in that state but opening the door makes it go to off - of course it stays on if you clip the seatbelt in (behind you) as it still thinks you are safely in the car. So with it ‘off’ but the rear open...
  6. G

    12 volt battery in later i3s--watch out

    I had this message come up once with my 60Ah - I was moving house and was packing the last things into the back with seats down. Car doors were open but car was switched off. State of charge was not recorded but must have been high as we were about to drive to the new location (170 miles)...
  7. G

    Charging 80 or 100%

    I disagree. There is no BMW technical data that supports anything other than plug the car in. This is for an i3. i4 is different as are all the other i models none of whom use the refrigerant cooling. Even the Mini SE has same drive but different glycol based cooling. There is evidence to...
  8. G

    Charging 80 or 100%

    Worth reading what aloha has said about the accuracy of the capacity reporting of the various apps.
  9. G

    Charging 80 or 100%

    I think like all these discussion disagreement requires proof. Battery university has all that and unfortunately it all related to single cell with no thermal management and no BMW safe guarding deep discharge etc etc etc. I leave the reader to Google.
  10. G

    2014 i3 REX with 11.7 Batt Kappa Max

    Yes I believe BMW told us at that meeting that it was around 85% indicated. They didn’t want to impact range on the very small battery below that level. We have used that ever since although I have never found that identified in any workshop manuals.
  11. G

    Charging 80 or 100%

    I agree on a lot of this but the practicalities are not quite how asserted. Again it is battery university, single naked cell, no deep discharge protection, no overcharge management, no thermal management, 1C charge and discharge. We don’t have that. - Calendar degradation - yes nothing...
  12. G

    Charging 80 or 100%

    First - I like the logic but the 10% buffer was at the top in the early models. So that negates most of what is calculated from there on. Current models are different I agree. Second - if you don’t charge higher there will not be cell balancing. I can’t see how that fits with the argument...
  13. G

    2014 i3 REX with 11.7 Batt Kappa Max

    We think the level at which cell balancing doesn’t happen is 85%. Yes I did meet with engineers in UK - we had a mega meet at Farnborough BMW HQ. Was very informative. Pictures I took at that session are in David Bricknell’s excellent book. I suspect as we have had only 1 or 2 documented...
  14. G

    Charging 80 or 100%

    Cell balancing also is passive top end. That only happens on completion of charging when the level is above 85%. Indicated. If you only charge to 80% indicated the cells will become unbalanced and a reduction in charge capacity and therefore range will occur.
  15. G

    Charging 80 or 100%

    Calendar degradation occurs irrespective of charge level. Thinking that a low level of charge which save on degradation is naive at best and misleading at worst. Calendar degradation is what it says. 1-2% per annum irrespective of charge level. Also BMW engineered a refrigerating cooling...
  16. G

    Charging 80 or 100%

    This ignores the fact that there is a top end ‘reserve’ not available which prevents charging above 85% actual? So unless one qualifies the remarks about ‘100%’ that advice in itself is worthless. The manual used to state leave it plugged in and there was no system iDrive mechanism to ‘stop’...
  17. G

    Electric problem

    I remember that. They have a guy who does it but it’s only economic in batches. So they wait until they have 20 and then send them off for resoldering. It’s about 10:17 into this video under the ‘Internal’ section. Doesn’t show repair just explains that the LEDs need replacing as they are...
  18. G

    12V battery step by step and preventing errors

    The 12v is charged when the HV is being charged. Could be why the poor things are dying if they are not left plugged in at least some of the time and mileage is relatively low?
  19. G

    2014 i3 REX with 11.7 Batt Kappa Max

    Did the 60ah get charged to 100% to enable cell balancing? This is what happened to mine 2014 when I only charged it to 80%
  20. G

    Help no heat

    Just as a matter of info. In the UK Wisley just published their prices. What is interesting is the range of items and what a fix should cost. Main not translate to USA.
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