Battery always at 11.4 V; Static current draw 0.25 A... Normal? | Page 2 | FerrariChat

Battery always at 11.4 V; Static current draw 0.25 A... Normal?

Discussion in 'Technical Q&A' started by Mike328, Jan 21, 2004.

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  1. ChrisfromRI

    ChrisfromRI Karting

    Jan 28, 2003
    230
    Foster, RI
    Full Name:
    Chris F
    #26 ChrisfromRI, Jan 22, 2004
    The battery itself will pull down the charging voltage if measured at the battery terminals, so I don't think this is an accurate place to measure the charging voltage.

    My trusty '88 Saab draws a fair amount of current all the time, and has done this since the day it was new. This happens to be normal for that car and it is absolutely no problem if the car is driven regularly, since the battery gets topped up each time the car is driven (its charging circuit works right). However, two to three weeks of non-driving, and leaving the car sit, has always resulted in a dead battery, over all of the 16 years I've owned the car. Brand new batteries might last a little longer. The cure has been simply to drive the car. I think I'm on maybe my fifth or sixth battery over the 16 years, which seems reasonable.

    IMO batteries designed for high cold cranking amps (e.g.: your red top) do not like a constant draw, and never being brought back up to a full charge. OTOH, they should be able to sustain the occasional very short duration mishaps that you have incurred, because of the plate structure of a high CCA battery.

    I happen to use a blue top in my 308, and it is normally trickle charged whenever parked, since my 308 is not regularly driven. I installed a battery charger connector behind my front license plate, so I just pull in and plug in. My understanding is that a blue top is better for my application (mine is the Exide/Champion version of the sealed spiral cell six-pack cased battery, equivalent to an Optima). My application happens to be similar to boats as they are also not regularly driven, have doodads running all the time (like alarms), and are frequently placed on a charger. BTW, it cranks fine.

    One easy place to look for the low charging problem is a bad electrical connection in the charging circuit. Ohm's law: extra resistance from a bad electrical connection = voltage drop as current is drawn. I had this very problem with my pickup truck, and had already replaced the alternator and the battery before finding a corroded connection within a black plastic corrogated cable conduit, two feet away from the alternator.

    Kind Regards, Chris
     
  2. Mike328

    Mike328 F1 Rookie
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    Oct 19, 2002
    2,655
    Boulder, CO
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    Mike
    #27 Mike328, Jan 23, 2004
    GREAT NEWS!

    I pullled the Optima and brought it in to Pep Boys. Before they take it back, they run a formal test.

    WOOHOO! I called, and they said it was indeed bad. Basically, free new Optima Red Top. EXCELLENT! I was sooo worried they were going to say that it was FINE :) Nope, definitely bad. Which means hopefully it's not an alternator problem (which was just rebuilt!).

    Any idea what could have caused it to go bad? I'll find out soon (tonight) what the problem was exactly... Bad cell?

    --Mike
     
  3. Mitch Alsup

    Mitch Alsup F1 Veteran

    Nov 4, 2003
    9,267
    #28 Mitch Alsup, Jan 23, 2004
    The web sites indicate the biggest reason the battery and or cells in batteries go bad is: sulfation.

    The biggest cause of sulfation: insufficient charging voltage or duration.
     
  4. Mike328

    Mike328 F1 Rookie
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    Mike
    #29 Mike328, Jan 23, 2004
    Is there an updated Voltage Regulator that would up the charging voltage for these particular batteries?
     
  5. ChrisfromRI

    ChrisfromRI Karting

    Jan 28, 2003
    230
    Foster, RI
    Full Name:
    Chris F
    #30 ChrisfromRI, Jan 23, 2004
    Great news!

    -- but plan on going back next year for another one if you don't figure out the reason why you are not sufficiently charging the battery.

    Kind Regards, Chris
     
  6. Mike328

    Mike328 F1 Rookie
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    Oct 19, 2002
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    #31 Mike328, Jan 23, 2004
    I agree, gotta trace it down. One possibility is frequent discharges of the battery by the 250ma load over a week or so of sitting (labor day / thanksgiving etc). Red tops don't like this, and they say not to use red tops if you have an alarm or other constant-draw accessory (like my keyless entry system).

    From the Optima web site:
    In any vehicle or equipment that will use the battery only for Starting, Lighting, & Ignition requirements and has a properly working alternator, the OPTIMA Red Top™ Starting Battery will perform extremely well, often providing up to two times longer life than conventional batteries. If the vehicle has few or no after-market accessories and uses a stock or upgraded alternator, the OPTIMA Red Top Starting Battery is the appropriate choice.
    Remember, it is possible for the customer to have a completely discharged Red Top OPTIMA that will not start their engine; the advantages of the Red Top are that it can accept a rapid recharge and it will recover from discharge many more times.

    To provide the customer the best OPTIMA solution, it is, necessary to consider both the application and the charging system before recommending the correct OPTIMA. For example, if your customer has a Ford Expedition with an after-market alarm system, which OPTIMA would you recommend? If the customer drives the car every day, the Red Top would be the correct choice, since the amperage drain will be nominal and the battery would be recharged on a daily basis. However, if the customer stores the vehicle for a long period of time with the alarm system engaged, you should recommend the OPTIMA Yellow Top, since the amperage drain over several weeks would damage a Red Top and reduce its life.


    Optima Yellow Top Information:

    The OPTIMA Yellow Top™ Deep Cycle Battery should be used in the following cases:

    Starting applications in high-accessory vehicles/High Cycling Applications. Vehicles with computers, extra radios, electronic components, lights, winches, etc. will create excessive amperage drain that can damage a starting battery. Recommend the OPTIMA Yellow Top to provide fast recharging and longer life due to its' ability to cycle over 300 times.


    Starting applications with low amperage draws. If your customer has a vehicle that sits unused for long periods of time, either OPTIMA will provide longer life due to reduced corrosion and sulfation. However, if the vehicle has an alarm, computer, or other low amperage drain, the Yellow Top will guard against deep cycling damage that can occur over long periods of time.


    To increase Reserve Capacity or Run Time. You must first identify how long the customer needs to use the battery to run a vehicle, accessory, or motor before without recharging. Each OPTIMA Yellow Top Deep Cycle Battery is rated at 120 minutes of Reserve Capacity at a 25 Amp draw. If your customer is planning on using their OTPIMA in a trolling motor that pulls 50 Amps, they will only get 60 minutes of run time. If they require more run time you need to install multiple batteries in parallel. It is important to understand what the customer expects in order to provide them with the correct OPTIMA solution.


    This information was taken from here:
    http://www.optimabatteries.com/usingOptima/index.asp
     
  7. Verell

    Verell F1 Veteran
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    May 5, 2001
    7,017
    Groton, MA
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    Verell Boaen
    #32 Verell, Jan 23, 2004
    Hi Mike,
    What alternator do you have? Is it the 65A one that the Carb'd 3x8s use? If so, send me the alternator part#, or the part# off of the regulator & I'll see if I can find an adjustable one.

    If you've moved up to the 80A BOSCH alternator that the QVs came with, then Transpo Electronics sells an adjustable replacement regulator. It's Transpo #IB372A. Transpo makes an exact replacement for the BOSCH regulator. It's Transpo #IB354. Both replace the Ferrrari# 121840 regulator, along with a whole raft of similar BOSCH regulators.

    http://www.transpo.de/catalog/US_cat.html

    You have to have a commercial account with a Transpo distributor to buy one tho. My Unobtainium Supply has an account. If you really want one send me eMAIL & I'll find out how much one costs.

    Try trickle charging the battery for 3-4 days, then see what the voltage measures. It takes a long time for a trickle charger to bring a high capacity battery up to full charge. Also, a long trickle charge often dissipates sulfation & recovers a damaged battery.

    Then see if you can track down that pesky 250ma load. Sure sounds like a small light bulb somewhere. Try looking the car over thoroughly some evening in a garage with the lights out. Something ought to be glowing.

    Also pulling fuses until a lot of it goes away should work also.
     
  8. thecarreaper

    thecarreaper F1 World Champ
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    Sep 30, 2003
    17,583
    Savannah
    #33 thecarreaper, Jan 23, 2004
    ok, i dont have a ferrari ( yet) but i have had many many cars. 1) as stated anything other than 12.5 volts is discharged. 2) shorting a spanner, wrench, screwdriver ect WILL DAMAGE A BATTERY !!!! BIG TIME!!!! it will also DAMAGE THE DIODES IN THE ALTERNATOR, i know this from many many hours of training and working on recip aircraft using both lead acid and Ni cadium batteries. 3) Mike i have specifically had "self exciting" voltage regulators put in my cars i keep. older cars with elderly wiring systems seem to love this and work great. it will be a simple test to see if tou have bad or damaged diodes, any decent starter/alternator shop should be able to put in a 1 wire self exciting voltage regulator. the problem i see is why when the stock system should be doing its job properly in the first place. i have shorted a battery/alternator with a wrench before and actually damaged the starter solonoid in the process. let me tell you that one took me awhile to diagnose! with the noted problems with the fuse blocks perhaps there is another problem preventing the charging circuit from doing its job under all loads and conditions. temperature and vibration are a very real issue in an older machine, car or aircraft. i love the 3x8 series and i wish you the best of luck, please keep us posted as i love any opportunity to learn more! michael
     
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