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Discussion Starter #1
Hi guys-

So a few months back I installed a Braille battery in my car - the smallest AGM battery they make. I usually drive the car several times a week, so I thought that would be enough to keep it charged.

Well, I soon found out that any more than 2 or 3 days without driving the car and the battery would not start it. Not wanting to go back to a bigger battery, I got a Battery Tender Jr. and wired it up, which works wonderful when I don't plan on driving it every day.

Problem is, yesterday I drove it in the morning, parked it, and this morning it didn't have enough charge to start it. It had sat for only a day. This is unusual. I'm now wondering if it just has a massive current drain, or if the alarm is really pulling that much current.

I'd really rather not dig into the wiring and remove the alarm system altogether (even though I don't think it would matter if I had it or not) but is there a fuse I can pull to turn off the alarm, or will that kill the immobilizer and thus keep me from starting the car?

I was thinking maybe a switched fuse that I would wire in to disable the alarm when I was parked, thus killing the big current draw on the battery, but still keep the ECU alive.

I really don't want to go back to a big heavy battery but I also don't want to use a full cutoff as I have a short commute and the ECU re-learning every two days doesn't sound like a good thing for the ECU, engine, or my fuel mileage.



Any ideas on how to help this situation?
 

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Knowthatfeelbro.jpeg

I had this exact same problem with my B106, went with Chimera battery. Worth every penny.
 

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Gamera The Atomic Turtle
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do you have your immobiliser switched to "active arming" so that it doesn't draw any current until you alarm your car? So that the pesky blinking red light doesn't blink everytime you get out of the car or switch the motor off? That will fix your problem i think - i have an Odyssey pc-625 battery installed for my clam hinge installation,, and a cteck battery tender, but i can last a week with the immobilizer's passive arming feature switched off. Do you know how to program your Cobra alarm to do this?
 

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He's on fire!
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sounds like you've drawn the battery down so low that you're not getting a full charge on it anymore
 

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Gamera The Atomic Turtle
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my thought also - still - you gotta kill the immobilzer auto arming stuff. That will kill the poor little battery. And it's easy to do, and cheaper than that very expensive battery. Don't get me wrong, I'd love a Chimera.
 

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Absolute power does what?
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do you have your immobiliser switched to "active arming" so that it doesn't draw any current until you alarm your car? So that the pesky blinking red light doesn't blink everytime you get out of the car or switch the motor off? That will fix your problem i think - i have an Odyssey pc-625 battery installed for my clam hinge installation,, and a cteck battery tender, but i can last a week with the immobilizer's passive arming feature switched off. Do you know how to program your Cobra alarm to do this?
Same problem here, whats the procedure?
 

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do you have your immobiliser switched to "active arming" so that it doesn't draw any current until you alarm your car? So that the pesky blinking red light doesn't blink everytime you get out of the car or switch the motor off? That will fix your problem i think - i have an Odyssey pc-625 battery installed for my clam hinge installation,, and a cteck battery tender, but i can last a week with the immobilizer's passive arming feature switched off. Do you know how to program your Cobra alarm to do this?
I also lock / unlock with the key and avoid arming the alarm.
 

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Gamera The Atomic Turtle
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absolutely. I don't even lock mine actually, but I live in NH.
 

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Gamera The Atomic Turtle
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What is the point in having a small capacity (AH) battery to save weight if it will not start the car. When a lead acid battery discharges substantially, it seldom recovers enough to retain a full charge. The alarm system "on" draws 42.5ma, system "off" 20.5ma. Instruction to program for "active" arming of the immobilizer are here ;http://www.lotustalk.com/forums/f320/remote-key-fob-immobilizer-misc-alarm-programming-70940/
Michael
that's a good point. In my case the PC-625 is to save space, not weight. BOE relocates the battery to the firewall during a typical clam hinge install, and that is the largest footprint they can sqeeze in under the fuel filler.
 

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Discussion Starter #13
Your signature ways Automotive Engineer.

One could bust out the volt-ohm (amp) meter and pull fuses and figure out the current drains?

Yes, I am. Three degrees worth, and I work for a well known sports car manufacturer these days after a tenure doing composite research for an F1 team.

I am also 6'2" and have a tiny garage where I can barely open the doors, let alone crawl under the dash of the car with an volt meter and pull one fuse at a time while reading current draws.

I didn't know about the immobilizer arming options. Mine always flashes the red light after about a minute of me turning off the car/not starting it after getting in. So looking into that first is a good start.

See... that's why this forum is great.
 

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my thought also - still - you gotta kill the immobilzer auto arming stuff. That will kill the poor little battery. And it's easy to do, and cheaper than that very expensive battery. Don't get me wrong, I'd love a Chimera.
Normally I'd agree with you, but you take into account the battery, NCI tie down, cutoff switch or tender and you're not too far from the Chimera RBS. except with the RBS you get to use the immobilizer/alarm like it was meant to be used with no hassles of turning power back on, unplugging the tender or not knowing if it will start.

I know it sounds like excuses for spending such a large amount of money, but I think i paid for the convenience of a standard lead acid and performance of an AGM.
 

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Gamera The Atomic Turtle
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sure - my only arguement would be is that the immobilizer is not supposed to be used that way at all. Why? Because it's a pain in th a$$ to have to push that freakin' button EVERYTIME you get in the car. Really annoying. Do love the Chimera for it's technical excellence though. It's a sweet piece of gear. Unless you just LOVE running your battery down, switch that immobiliser off "passive arming" via the programming options!!!
 

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Gamera The Atomic Turtle
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hmmmm...would this be as simple as switching the 12vdc supply to the alarm module off? Wouldn't we still want to program immobilizer for active arming too? Aren't they seperate systems in that respect? Or am I completely wrong? (the most likely choice:))
 

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hmmmm...would this be as simple as switching the 12vdc supply to the alarm module off? Wouldn't we still want to program immobilizer for active arming too? Aren't they seperate systems in that respect? Or am I completely wrong? (the most likely choice:))
Even with it off it still draws 20.5ma
 

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Gamera The Atomic Turtle
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ok - so if we switch the 12vdc to the alarm, there is zero draw - regardless of the status of the immobilzer's settings? Because the immobilizer will not function if the alarm is turned off in this manner? Sorry to be so ....uneducated.
 

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ok - so if we switch the 12vdc to the alarm, there is zero draw - regardless of the status of the immobilzer's settings? Because the immobilizer will not function if the alarm is turned off in this manner? Sorry to be so ....uneducated.
That's correct, except there will still be a draw from the engine ECU and radio.
Michael
 
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