Car Battery/Car Alarm/Capacitor Question

[computer-joe]

Hello, I'm not sure if i should be posting this in a car forum, but since this forum deals with electronics and it's a battery question/capacitor i thought maybe i would try here


My car alarm is using taking too much power from my car battery(12V) Since it's a 2-way car alarm the amount of electric draw is normal. Usually, at 8pm the battery is at 12.66V, but when i test it in the morning the battery is at about 12.39V(which is enough to start the car. During summer i have no problem.

But when temperatures reach -20 to -30 in winter, and i test the battery in those super cold mornings the battery is at 12.16. Since it's very cold, usually the first crank won't start the car and by the second crank it usually starts, but if it is even colder, i might need a third crank and by then the battery is about 10V and no enough power to crank. If it's -30 or more, forget it. the battery is not at 100% so might as well not try it.

If i disconnect my battery overnight, and connect it back in the morning the car will start with no problem because the battery is at 100% so it has enough cranking power to start it at the first crank. Since my car is small i can't fit a bigger and more powerful battery in the car. So really i am out of luck. My only choice is to just get rid of the alarm system.

Anyways, Someone suggested a capacitor(might work) the ones they use in car audio systems. They explained to me it works but i have forgotten and i can't find anything reliable online.

How exactly does a car capacitor work. I know my car's alternator charges the 12V battery and then my car alarm system takes power from the 12V battery.

But with a capacitor, where exactly does it fit in.

As far as i know, the alternator charges both the 12V Battery & the Capacitor.

Afterwards, would the alarm system take power from the capacitor first, then after it is drained would move on to the 12 battery? But i'm doubting the capacitor would be fully drained by the time i wake up in the morning(8 hours later), and since the capacitor is not taking power from my battery, my battery would be at 100% every morning, then its sounds like a solution.

Is that how a capacitor works? Does it supply power directly to the car alarm, or

do capacitors charge the 12V battery when it starts to get low, I am guessing not because capacitors probably do not have enough power to charge a 12V battery, or do they?

I don't really understand what a capacitor is, Does anyone here know how capacitors work?

 

[Rayregula]

Afterwards, would the alarm system take power from the capacitor first, then after it is drained would move on to the 12 battery? But i'm doubting the capacitor would be fully drained by the time i wake up in the morning(8 hours later), and since the capacitor is not taking power from my battery, my battery would be at 100% every morning, then its sounds like a solution.

After the capacitor has been drained (it would not take very long) it would recharge itself from your battery and you would be back where you started.

 

[(*steve*)]

An alarm that discharges the battery that quickly does not sound right.

However, a simple solution might be to connect a charger overnight. A bit of a pain in the bum though.

 

[duke37]

Surely your trouble is the temperature of the battery. One crank will warm the battery for the second crank.
Use thin viscostatic engine oil.

An auxilliary warm battery will do better than a capacitor with very limited energy.

Park your car over a volcano.

 

[KTW]

Check the current draw from the alarm and compare it to the specs.

 

[davenn]

My car alarm is using taking too much power from my car battery(12V) Since it's a 2-way car alarm the amount of electric draw is normal. Usually, at 8pm the battery is at 12.66V, but when i test it in the morning the battery is at about 12.39V(which is enough to start the car. During summer i have no problem.

An alarm that discharges the battery that quickly does not sound right.

you either have a faulty alarm unit or a failing car battery

Afterwards, would the alarm system take power from the capacitor first, then after it is drained would move on to the 12 battery? But i'm doubting the capacitor would be fully drained by the time i wake up in the morning(8 hours later), and since the capacitor is not taking power from my battery, my battery would be at 100% every morning, then its sounds like a solution.

Is that how a capacitor works? Does it supply power directly to the car alarm, or.....

no, no, no and no it doesn't work anything like that

the capacitors people install in cars for use with high power sound systems just stop the brief sags in voltage during the large current peaks drawn by the amplifier


Dave

 

[computer-joe]

An alarm that discharges the battery that quickly does not sound right.[

However, a simple solution might be to connect a charger overnight. A bit of a pain in the bum though.

I think so too but the alarm technician said it is normal for a 2 way alarm system, He said he had the same problem and since my battery is small it would make a difference,

I always connect the block heater and battery blanket when it reaches -15 or lower, and my car starts fine

Surely your trouble is the temperature of the battery. One crank will warm the battery for the second crank.
Use thin viscostatic engine oil.

An auxilliary warm battery will do better than a capacitor with very limited energy.

I have always use synthetic oil for many years now, it has helped a lot. In -20 -30 my car always started. But when i first used normal oil, it would start but i could always hear the engine struggling to turn

This was before i installed the car alarm.

Check the current draw from the alarm and compare it to the specs.

The technician said it was pulling a normal draw for a 1 way system

you either have a faulty alarm unit or a failing car battery

I think it might be the battery, but its only a year old




Heres some more i forgot to add, Last year I was away for 3 weeks and when i came back my battery was drained, i forget to disconnect the battery, i had to boost it,

I got it checked and the technician said there was 1 cell not good,


Last month i was away for 1 month, and i disconnected the battery completely(just the negetive) and when i came back i plugged it back in and my car started fine, it was even cold that day,


I read online about many people having problems with 2 way car alarm systems, they cant leave their car for more than 2 weeks or it drains the battery.


The point is, i shouldn't have to plug my car, or anything as when i first bought the car it didn't have a car alarm and i never had any problems, as far as i remember... it an old car

I believe its the car alarm system but im not able to confirm it 100% which is driving me nuts!!

My next step is to buy a new battery and keep testing it with a multimeter,

Im not sure if its because i let the battery drain completely once, you would think if it drains once, it would still be ok,

I cant remember how it was with the other battery, i just remember i always let it drained, when i went away for long trips, i never disconnected the battery,

Starting from last year i always disconnected the battery if im going away for a long time,

If my new battery has the same problem, then my next step is to disconnect temporary the car alarm completely , and see if i still have the same problem,

Advice to everyone, dont buy 2 way alarm systems for small cars, the technician said 1 way systems don't pull as much power as 2 ways, But really all i use is the remote starter in the winter, so i don't need an alarm system.

i will keep updating this, might take a year or two to solve this as winter is almost over and my battery works fine in summer

 

[duke37]

See KTW #5.

You cannot test the capacity in a battery with a voltmeter. You need to find the drain current and see how much of the battery capacity has been used up.

Why does Greenland have a red flag?

 

[KTW]

I think it might be the battery, but its only a year old

Get a load test done on the battery.

 

[Gryd3]

I think so too but the alarm technician said it is normal for a 2 way alarm system, He said he had the same problem and since my battery is small it would make a difference,

The installer is full of crap. I have a 2-way alarm installed in an old '93 Honda Civic. They use pretty small batteries.
I can leave the car sitting easily for a month without incurring any battery level issues... That said, that is only after I bought a new battery... as I had a habit of leaving my lights on when I walk away from the car. It would drain and damage the battery every time I ran it flat forgetting the head-lights on.

The only way I can see the installer being correct, is if you have formed an unhealthy habit of checking the temperature and voltage of your car numerous times a day remotely with your key-fob... Every time I do this, my corner lights flash and the current draw goes up.

 

[Rayregula]

Why does Greenland have a red flag?

And Greenland is partially covered in ice!

 

[mayank tanwar]

I think your battery is very weak, if any cell of a battery is dead then battery creates problem like that

 

[computer-joe]

update!

It seems when i let the old battery die once, it wreaked a cell inside. I put a special tester to it.
Finally my battery completely died. Had to call uber to give me a boost. I was hoping it would last before winter.

Aways i bought myself a brand new one, and guess what! same thing..

12.70v in the evening, and by morning 12.40v

But today.. i fixed the problem..

i bought a dash cam,and i was installing it but the car alarm receiver responder antenna was in the way. I disconnected temporary, and left it disconnected.

I've tested my battery again and guess what.. this morning 12.80v!

no battery drainage!

for years i've had this problem, and i've finally found the problem!

The stupid car alarm 2 way system was the culprit. The receiver antenna is always sending out a signal to tell the remote if it's been broken into or not.

I can turn this off, but it turns it off from the remote only, and not the receiver antenna. So the antenna is still sending out signals, but the remote is not listening to it.

By disconnecting the 2 way receiver antenna the car alarm system is no longer able to send or receive signals.

Therefore, not draining my battery.

I can't remote start my vehicle, or lock/unlock my vehicle from the remote.

But that's not a problem, since i haven't used the remote key/alarm in years.

I've always been using the key to unlock my car. I found the remote too bulky.

I do use the alarm system sometimes, if i go in bad neighborhoods, which is like once a year.

When i do, i can simply just plug the responder/receiver antenna back in. It takes a quick second.



I can't believe the technician was unable to tell me this simple solution, he has no idea...and it seems people have this problem often online and no one has thought about disconnecting the receiver antenna

this battery drain that i've been having for years, solved! simply by disconnecting the receiver antenna

unbelievable! 12 years having this problem!
unbelievable! 12 years no one was able to tell me this simple solution!



I will never again get a 2-way car alarm system. 1 way would be fine.



For anyone that's wondering what the receiver antenna looks like here it is:



it usually goes on the windshield
it sends and receives signal constantly
drains my battery from 12.80 to 12.40 over night,
car alarm system: Viper 791XV

which is not a lot, but in the winter, in -20, i need that extra .40v

lesson: never get a 2-way car alarm system,


its an old car.. so i'm not too worried about anyone stealing it.
but
i wonder if they sell 1 way antenna's..
i wonder if i opened the antenna, if there would be a way to block the 2 way and keep 1 way,

i really wish i knew more about hacking electronics..


anyhoo...

mission solved!

 

[Gryd3]

update!

It seems when i let the old battery die once, it wreaked a cell inside. I put a special tester to it.
Finally my battery completely died. Had to call uber to give me a boost. I was hoping it would last before winter.

Aways i bought myself a brand new one, and guess what! same thing..

12.70v in the evening, and by morning 12.40v

But today.. i fixed the problem..

i bought a dash cam,and i was installing it but the car alarm receiver responder antenna was in the way. I disconnected temporary, and left it disconnected.

I've tested my battery again and guess what.. this morning 12.80v!

no battery drainage!

for years i've had this problem, and i've finally found the problem!

The stupid car alarm 2 way system was the culprit. The receiver antenna is always sending out a signal to tell the remote if it's been broken into or not.

I can turn this off, but it turns it off from the remote only, and not the receiver antenna. So the antenna is still sending out signals, but the remote is not listening to it.

By disconnecting the 2 way receiver antenna the car alarm system is no longer able to send or receive signals.

Therefore, not draining my battery.

I can't remote start my vehicle, or lock/unlock my vehicle from the remote.

But that's not a problem, since i haven't used the remote key/alarm in years.

I've always been using the key to unlock my car. I found the remote too bulky.

I do use the alarm system sometimes, if i go in bad neighborhoods, which is like once a year.

When i do, i can simply just plug the responder/receiver antenna back in. It takes a quick second.



I can't believe the technician was unable to tell me this simple solution, he has no idea...and it seems people have this problem often online and no one has thought about disconnecting the receiver antenna

this battery drain that i've been having for years, solved! simply by disconnecting the receiver antenna

unbelievable! 12 years having this problem!
unbelievable! 12 years no one was able to tell me this simple solution!



I will never again get a 2-way car alarm system. 1 way would be fine.



For anyone that's wondering what the receiver antenna looks like here it is:


View attachment 34618
it usually goes on the windshield
it sends and receives signal constantly
drains my battery from 12.80 to 12.40 over night,
car alarm system: Viper 791XV

which is not a lot, but in the winter, in -20, i need that extra .40v

lesson: never get a 2-way car alarm system,


its an old car.. so i'm not too worried about anyone stealing it.
but
i wonder if they sell 1 way antenna's..
i wonder if i opened the antenna, if there would be a way to block the 2 way and keep 1 way,

i really wish i knew more about hacking electronics..


anyhoo...

mission solved!

Glad you found the culprit!
I've got a CompuStar 2-way alarm, but it does not send a heartbeat to the remote. It's radio silent until a message needs to be sent. I guess inbound signals could be waking the device up to process. Hard to tell without documentation or cracking it apart.

 

[computer-joe]

update 2!!!!!!!!!!!!!!!


i found out the exact reason why my battery was being drained so much, it was a parasitic drain
and i found exactly where it was happening,

remember how i disconnected the receiver antenna?


well when i took a closer look at the wiring, i noticed some bare wire
since the receiver antenna is attached to the windshield, it is exposed everyday to the sun
It was then that i realized that the sun over the years had destroyed the outer later of the wiring
it had left almost all of the wires exposed

when i looked more carefully, i noticed the blue and red wires were touching, im going to assume this is where the parasitic drain was happening,

I carefully took a pin, and separated the wires that were touching

After almost one month of testing the battery with the receiver antenna plugged in, the problem seems to of have disappeared, my battery is at 100% every morning,

the alarm system is barely sucking any power from the battery
i thought i would notice a little bit of power being sucked from the battery because it was a 2-way
but nope! the battery is 100% every time,

people were right, the alarm system should barely be taking any power from the battery

i thought it was normal for a 2-way alarm system, but
it was those 2 wires, the blue and red that were touching, it was causing a parasitic drain



here is 2 pictures of the receiver antenna




as you can see the cladding(not sure if that's what its called), on the wires has melted from the sun throughout the years
They were touching before but i separated them

since the wires are not touching, my battery is always at 100%

does anyone know what i could pour on those exposed wires to cover them up?
I was thinking of taking a glue gun, and pouring glue on them, so they are not exposed,

it's too small for electric tape, although i could do it, if i really tried hard

or i can just leave it this way, i dont think the sun can destroy copper can it?

 

[Gryd3]

I'd certainly give liquid tape a try, but the hot-glue option would work just fine.
Glad you found the culprit. I found it strange that the alarm would drain a battery like that.

 

[ChosunOne]

Thanks for the update, Computer-Joe. That was really puzzling me before you found the exposed wires touching. I'm not expert in car alarms, but it didn't sound right that _any_ alarm designed for cars would put that much drain on a battery.

For what it's worth, I agree with Gyrd3: The technician you spoke to was full of crap when s/he said it was normal. It's possible s/he is an installer rather than a service tech. Installers can put equipment into cars without really understanding how it works. Service techs have to understand it to fix it. It's a not-so-subtle distinction that a lot of people are not aware of.

 

[computer-joe]

I ended up going with liquid electrical tape, it was harder to apply then i thought it would be

it turned out bad, but at least the wires aren't touching anymore,

i really hate working on cars, i taped it up, put it back, now everything is working fine

i hope that lasts for another 5 years, then i'm ditching my 12 year old car and getting myself a new one

so sick of cars



my car is too old for anyone to steal it now, so there is no need for an alarm system,
and i rarely go into bad areas,
the only thing i use it for is to remote start it during the winter months