Page 1 of 2 12 LastLast
Results 1 to 25 of 30

Thread: New Battery Time - Options have changed

  1. #1
    Join Date
    May 2008
    Location
    New Jersey, USA
    Posts
    699
    My Cars
    Dinan 8

    New Battery Time - Options have changed

    So its seems that the Dinan 8's battery or probably both batteries need replacing. I originally installed a set of Interstate MTP-93 monsters back in 2010 but they are no longer being manufactured, so I need to use something else now.

    I know my decisions come down to 1 or 2 batteries... lead acid or AGM/sealed. I believe that H6's (750CCA) and H8's (900CCA) should both fit correctly.

    What is everyone doing in 2018? Best place to purchase? Costco, Walmart, Advance Auto, Autozone, etc?

    Thanks,

    -JRW

    Glacier Blue 1991 Dinan 8 | Chasis CB73392 | 1 of 50 Produced
    Built for PGA Pro Mark Calcavecchia
    Twin Turbo 5.0L V12 w/ Air-to-Air Intercoolers
    525hp - 589ft/lbs tq

  2. #2
    Join Date
    Jan 2016
    Location
    Ca
    Posts
    6,981
    My Cars
    2001 525it
    We installed 2 agms in a Customers car along with 2 battery tenders because the car sits so much

  3. #3
    Join Date
    Sep 2011
    Location
    Vancouver Canada
    Posts
    419
    My Cars
    '91 850i, E39 & E46 Cars
    Just checking the Interstate website, they show for a 1991 850i to use their MTP-93/T8 battery. These fit a large range of newer cars, so I am sure you could find this battery available from a local Interstate dealer. / Henry

  4. #4
    Join Date
    Nov 2010
    Location
    Central, MO, USA
    Posts
    415
    My Cars
    1993 BMW 850Ci
    The interstate option still fits... but the vent hole has been moved from center (like the OEM batteries) to the end. You will need the adapters (that are sometimes supplied with the battery) to get a connection to the stock ventilation tubes.

    Mark in mid-MO
    1993 BMW 850Ci 6-speed
    2011 Cadi CTS coupe 6-speed

  5. #5
    Join Date
    Feb 2016
    Location
    Brooklyn, NY
    Posts
    294
    My Cars
    1995 840Ci, 2013 X5

  6. #6
    Join Date
    Feb 2016
    Location
    Brooklyn, NY
    Posts
    294
    My Cars
    1995 840Ci, 2013 X5
    Quote Originally Posted by jclausen View Post
    We installed 2 agms in a Customers car along with 2 battery tenders because the car sits so much
    Maybe your post glossed over something, but it sounds like you just put two battery tenders on the same circuit, as the batteries are wired in parallel. So neither will work properly.




  7. #7
    Join Date
    Jun 2009
    Location
    Canada
    Posts
    475
    My Cars
    95 BMW 850
    Quote Originally Posted by jclausen View Post
    We installed 2 agms in a Customers car along with 2 battery tenders because the car sits so much
    I guess you can hook up 2 chargers to the 2 batteries. I always separate the batteries by undoing the negative cable but I don't believe that is necessary.

    - - - Updated - - -

    Quote Originally Posted by ltbrett View Post
    Maybe your post glossed over something, but it sounds like you just put two battery tenders on the same circuit, as the batteries are wired in parallel. So neither will work properly.


    But the chargers are working in parallel as well. They are both supplying the same voltage. They just supply more amps.

  8. #8
    Join Date
    Feb 2016
    Location
    Brooklyn, NY
    Posts
    294
    My Cars
    1995 840Ci, 2013 X5
    Quote Originally Posted by llcarlos View Post
    I guess you can hook up 2 chargers to the 2 batteries. I always separate the batteries by undoing the negative cable but I don't believe that is necessary.

    - - - Updated - - -



    But the chargers are working in parallel as well. They are both supplying the same voltage. They just supply more amps.
    Battery tenders are voltage sensing. With two in parallel, when one is putting out charging voltage, the other senses an overvoltage and stops charging. At best, only 1 battery tender will be working. At worst, their voltage sensing logic will get confused so neither will charge.

  9. #9
    Join Date
    Oct 2008
    Location
    Seattle
    Posts
    1,823
    My Cars
    E31 E38 E65
    AGM only..Lead Acid is trash

    I'm currently running 3 Odyssey 31M-PC2150 Batteries..
    *~*Yamaguchi-gumi Syndicate Member #59,005 *~*
    [ Bippu Couture ] ( D_G ) [ FALKEN Tires]

  10. #10
    Join Date
    Jul 2007
    Location
    Cave Creek, AZ
    Posts
    1,117
    My Cars
    1993 850ci 2001 M5 / Z3M
    Single H8 AGM - never look back
    Regards,

    Brian
    Cave Creek, AZ

  11. #11
    Join Date
    May 2008
    Location
    New Jersey, USA
    Posts
    699
    My Cars
    Dinan 8
    Thanks for all of the replies. I ended up going with a single H8 AGM battery from Advance Auto. With a 25% coupon and the core, it was about $150. Not too bad. I might get a second one at some point. She started right up afterwards.

    -JRW

    Glacier Blue 1991 Dinan 8 | Chasis CB73392 | 1 of 50 Produced
    Built for PGA Pro Mark Calcavecchia
    Twin Turbo 5.0L V12 w/ Air-to-Air Intercoolers
    525hp - 589ft/lbs tq

  12. #12
    Join Date
    Nov 2013
    Location
    Whitney, TX
    Posts
    1,238
    My Cars
    97 850CI
    Quote Originally Posted by bdiefAZ View Post
    Single H8 AGM - never look back
    This is next on my list. The empty battery spot will become audio equipment storage.
    Desecrator of all things Sacred

  13. #13
    Join Date
    Jul 2007
    Location
    Cave Creek, AZ
    Posts
    1,117
    My Cars
    1993 850ci 2001 M5 / Z3M
    I will be using my empty battery chamber for road trip tool storage, 15 inch tool bags work great for this. The extra trunk space will be welcome on long trips.

    Remember - disconnect the battery cross cable during this conversion, it is a necessary step. This cable can be confirmed with a multi-meter.
    Regards,

    Brian
    Cave Creek, AZ

  14. #14
    Join Date
    Nov 2015
    Location
    Ger
    Posts
    29
    My Cars
    E31 850iA 1992
    one battery is enough.
    I have only on the right side a 85ah battery. (the +cable from the right to the left in on the right side removed from the +terminal)
    From the trunk to the starter there is only one +calbe. So its equal if there are one or two battereys on this cable.

    The E32 M70 is delivered with 75ah or 85ah. So, this must also be fine for the E31.

    The two batterys have a problem. They are every time loading each other.

    If one has 12,31V and the other 12,30V - there is a current.
    If one has 12,305V an the other has 12,299 - there is a current.
    ..and so on.

    The E31 was equipted with 2*65Ah. The compete capcity is not 130ah.

    If someone will goes down to one battery, look to the battery place - there are positosn to handle 3 lengths of battery.

  15. #15
    Join Date
    Jun 2009
    Location
    Canada
    Posts
    475
    My Cars
    95 BMW 850
    The 65ah AGMs were starting to fail too often and the car wouldn't start with only the driver side battery hooked up so I switched them around and I left the positive cable on the left battery but took the short negative cable off completely. Now the car can sit for 2 weeks and still start. The charger shows both batteries are fully charged. I'm not sure of the point of dragging a spare battery around but you never know.

  16. #16
    Join Date
    Nov 2008
    Location
    Maryland
    Posts
    3,193
    My Cars
    not enough
    https://www.bimmerforums.com/forum/s...ght=battery+h8

    both 8ers have H8's from Wally world. Cheap, readily available and reliable. No complaints here.
    CB42366 - 1991 850i 6-speed. Brilliantrot & Black Nappa Leather
    CD00144 - 1994 850CSi. Hellrot & Black Nappa Leather


    My other projects:
    Supercharged Tbirds, V8 Tbirds, V8 Mustang Convertible, Audi V8 Quattro & Audi S8

  17. #17
    Join Date
    Dec 2006
    Location
    Sunny Cali,
    Posts
    8,730
    My Cars
    6.5 second 69 Camaro
    After 12 years my Yellow Top Optimas are dead, They're so bad when i open the trunk the window drops every 20 seconds,) New Optimas in order this weekend.

  18. #18
    Join Date
    Jan 2011
    Location
    Oro Valley, AZ - USA
    Posts
    1,706
    My Cars
    see my signature
    Quote Originally Posted by DriftGirl View Post
    AGM only..Lead Acid is trash
    Hate to tell you, but AGM is still lead-acid technology

    That said, I'm a single H8 AGM convert myself. I'd only have two batteries in an E31 if it was a concours grade show car and had to be 100% OEM original. I think there are way too many drawbacks to two batteries in these cars, which typically only get driven sporadically.

    - - - Updated - - -

    Quote Originally Posted by E31 850i View Post
    If someone will goes down to one battery, look to the battery place - there are positosn to handle 3 lengths of battery.
    Note that not all 8 series have the threaded nut insert in all 3 positions. My 840 only has one. The holes are there for the inserts, but no threaded nut.

  19. #19
    Join Date
    Jun 2012
    Location
    Mundelein, IL
    Posts
    837
    My Cars
    840Ci/6 528iT Europa TCS
    I have been with a single AGM for a couple of years now and have never looked backed back. No vent tube and 20 less lbs.

  20. #20
    Join Date
    Jul 2007
    Location
    Cave Creek, AZ
    Posts
    1,117
    My Cars
    1993 850ci 2001 M5 / Z3M
    Out of curiosity, those that have converted to single battery, how many of you have removed the connecting cable for the driver's side battery?
    Regards,

    Brian
    Cave Creek, AZ

  21. #21
    Join Date
    Jan 2011
    Location
    Oro Valley, AZ - USA
    Posts
    1,706
    My Cars
    see my signature
    Quote Originally Posted by bdiefAZ View Post
    Out of curiosity, those that have converted to single battery, how many of you have removed the connecting cable for the driver's side battery?
    Just left it in, bagged both ends with latex gloves (to give the next guy pause) and tucked both ends up above the wheel wells. Did not see any reason to remove it altogether.
    2006 R53 JCW (British Racing Green) - 1994 E31 840Ci 6spd (AVUS Blue)
    2021 F56 JCW (Rebel Green) - 2000 E38 740i Sport (Titanium Silver)
    2017 F26 X4 M40i (Carbon Black) - 2007 E91 328iT (Deep Green)
    2012 E82 135i M Sport (Marrakesh Brown) - 2015 E84 X1 (Cashmere Silver)
    2005 E53 X5 3.0i Sport (Kalahari Beige) - 2000 E36/7 M Roadster (Oxford Green)
    2000 E38 740i Sport (Oxford Green) - 1999 E36 M3 Coupe (Fern Green)
    1995 E31 840Ci Canadian (Oxford Green) - 2000 E36/8 M Coupe (Oxford Green)
    2004 E46 330Ci (Oxford Green) - 2001 E36/8 Z3 3.0i Coupe (Oxford Green)
    2002 E39 525i Sport (Oxford Green) - 2002 E36/7 M Roadster (Oxford Green)
    2001 E53 X5 3.0i Sport (Oxford Green) - 2007 E63 M6 (Silver Grey)
    1995 E31 840Ci (Oxford Green) - 2006 E86 M Coupe (Sepang Bronze)
    2001 E39 530i Sport (Aspen Silver) - 2009 E92 M3 (Space Grey)
    2001 E38 740i Sport (Sahara Beige) - 2008 E92 M3 (Melbourne Red)
    2000 E38 740i Sport Canadian (Sahara Beige) - 1997 E31 850Ci (Jet Black)

  22. #22
    Join Date
    Sep 2010
    Location
    Finland
    Posts
    202
    My Cars
    bmw 850i M-tech
    For cars like E31, which are often driven irregularly, its better to use only one battery. One good 85-100Ah agm battery is enough for everything and gets charged to it's full capacity more often than two batteries, which are also often uneven. I don't know why bmw used two batteries but it's completely pointless.
    Last edited by mikae31; 09-02-2018 at 06:52 AM.

  23. #23
    Join Date
    Jun 2012
    Location
    Mundelein, IL
    Posts
    837
    My Cars
    840Ci/6 528iT Europa TCS
    I removed the cable to the other side. I also added a subwoofer and mono block amp. The amp is wired directly to the single battery and still no issues.
    In winter, or anytime the car is not used for a week or 10 days, I connect a little float charger/maintainer under the hood. I usually leave it for a day or two every other weekend and I always have a charge to start the car.

  24. #24
    Join Date
    Jan 2011
    Location
    Oro Valley, AZ - USA
    Posts
    1,706
    My Cars
    see my signature
    BTW like Rick, I ended up removing the L-R jumper cable from mine a few weekends ago too (although I hadn't originally planned to). I got neck deep in a really crappy phone removal, so I was in the 'remove all unnecessary crap' mode!

    This is just some of the wires that came out along with the phone.
    Last edited by Chamberlin; 10-02-2018 at 10:16 PM.
    2006 R53 JCW (British Racing Green) - 1994 E31 840Ci 6spd (AVUS Blue)
    2021 F56 JCW (Rebel Green) - 2000 E38 740i Sport (Titanium Silver)
    2017 F26 X4 M40i (Carbon Black) - 2007 E91 328iT (Deep Green)
    2012 E82 135i M Sport (Marrakesh Brown) - 2015 E84 X1 (Cashmere Silver)
    2005 E53 X5 3.0i Sport (Kalahari Beige) - 2000 E36/7 M Roadster (Oxford Green)
    2000 E38 740i Sport (Oxford Green) - 1999 E36 M3 Coupe (Fern Green)
    1995 E31 840Ci Canadian (Oxford Green) - 2000 E36/8 M Coupe (Oxford Green)
    2004 E46 330Ci (Oxford Green) - 2001 E36/8 Z3 3.0i Coupe (Oxford Green)
    2002 E39 525i Sport (Oxford Green) - 2002 E36/7 M Roadster (Oxford Green)
    2001 E53 X5 3.0i Sport (Oxford Green) - 2007 E63 M6 (Silver Grey)
    1995 E31 840Ci (Oxford Green) - 2006 E86 M Coupe (Sepang Bronze)
    2001 E39 530i Sport (Aspen Silver) - 2009 E92 M3 (Space Grey)
    2001 E38 740i Sport (Sahara Beige) - 2008 E92 M3 (Melbourne Red)
    2000 E38 740i Sport Canadian (Sahara Beige) - 1997 E31 850Ci (Jet Black)

  25. #25
    Join Date
    Jun 2012
    Location
    Mundelein, IL
    Posts
    837
    My Cars
    840Ci/6 528iT Europa TCS
    That's a lot of copper. Your car should be even faster now with all that extra weight removed. It was fairly easy to do and I bet now it looks even cleaner. I cut a piece of wood to place over the battery tray on the LHS so I would have a flat surface to store stuff.

Page 1 of 2 12 LastLast

Similar Threads

  1. New Battery Time
    By daka in forum 1996 - 2002 Z3 (E36/7, E36/8)
    Replies: 7
    Last Post: 11-11-2013, 01:36 PM
  2. New battery time for MZ4 Coupe
    By The HACK in forum 2002 - 2008 Z4 (E85, E86)
    Replies: 15
    Last Post: 02-11-2011, 02:08 PM
  3. New Battery Time
    By yeewiz in forum 1999 - 2006 (E46)
    Replies: 8
    Last Post: 10-29-2008, 08:04 PM
  4. time for new battery?
    By sickbeema in forum 1975 - 1983 (E21)
    Replies: 11
    Last Post: 01-22-2008, 10:53 AM
  5. Time for a change...considering new wheels.
    By vinnymac in forum 1992 - 1999 M3 (E36)
    Replies: 0
    Last Post: 06-10-2004, 02:34 AM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •