Dead battery
 

Hey guys, I've not used my car for 1 week. The battery is dead. I will only use it for this sunday...

Should I disconnect the positive terminal of my battery?

What are you hoping to accomplish by disconnecting it? I've left mine for a week before with no ill effects.

If it's dead, you better charge it before it stays dead. The longer you wait, the less chance it can be revived.

Disconnect it and recharge it while it is unhooked.

Jumping a car with a dead battery then letting the alternator charge it back up from dead is a sure fire way to kill a prefectly good alternator (assuming it was good to start with).

If you have the smart key/push button ignition, there is a lot more draw on the battery while parked than without. Mine went dead after sitting for about 8 days a week ago. Charged up and started without issue fortunately. If you know you won't use the car for some time, disconnecting or using a battery tender is probably a good idea.

shenanigans. there is not enough of a draw on the battery to drain it dead. there is no need to disconnect a battery for a small time like 8 days. maybe over a month, yes.

if your going to disconnect your battery like this^ then you should get a memory saver to plug in to save your settings, otherwise once you disconnect the neg cable you will reset all your settings to factory.

Or ditch the crappy battery that comes with the MT version of our cars and buy something with enough CCA's that you won't be left stranded. I ditched the crappy factory 390 CCA battery for a NAPA 640 CCA unit and life is much better.

Seriously.. A high compression engine and the stock batter is only 390 CCAs.. That's some BS right there. The AT version of our car I think got at least 500 CCAs (correct me if I'm wrong).

Not sure about that. From what I can tell my battery (Panasonic 55D23L) is only 390 or 400 CCA. Can someone with MT chime in on their battery number?

And fwiw my battery crapped out totally after about 30 months of daily driving.

Just disconnect both cables and charge it with a 2 amp charger, a lower amp charging is better than like a 6 amp. Keep it on charge the whole week it wont harm anything, if any cell plates are sulfated they will desulfate with a charge for a week. Unless batteries are damaged they won't go bad, batteries go dead from sulfation. You can snap a battery back to life if you do like a week or 2 on a six amp charge topping with distilled water every once in a while. Also look for anything that may be staying on when the car is off. Something is draining the battery, on a new car I'd get a multimeter and make sure you are putting out 13+ volts at 2000 rpm consistently from the alternator with lights and a/c on for a load. No drops at a steady 2000 rpm and the alternator is good. :party0030:

Thank you all for your inputs, just to let you know. Reason I disconnected it is due for the battery to not drain more power. I am not trying to accomplish anything, I will call Road Assistance to come jump start it. Since its nose in inside my garage.

How many time can I call scion road assistance (Canada) :D?

or you can take out battery and charge it inside home.
i've done it because of same reason my car's nose is at corner.
I left my car for 2 weeks in below 20 degree and it went dead. bought battery charger and charged inside garage then started the car right back up after one day

I agree that this usually wouldn't be the case, but this has been happening fairly often lately to people with the stock battery in the cold. There have been 4 similar threads in the last month.

http://www.ft86club.com/forums/searc...archid=8573373

I read in on of those threads that someone tested a new car on the lot and it was drawing 150mah while off (havent checked mine). From what ive found, the stock battery is 60ah. If these are both true, then the battery would go dead in just over 16 days in perfect conditions. The cold and the quality of the battery are both going decrease this time. This battery really doesnt seem to like the cold. For me it was getting below 0F while I was gone, never above freezing.

I agree. In fact a 60Ah battery discharging at .150A will reach 40% state of charge (60% depth of discharge) in 10 days.
At 40% SOC the voltage would only be 12 volts, and when you crank it would drop to below 11 volts.

My 2013 MT has the original battery and I find that I am low on charge if I make just a few short trips around town.
It seems that this car has a higher than average current draw under normal operating conditions than other cars.
Now I try to shut of all electrical systems before shutting the car off so that I have less load when I go to start it again.

I'm 100% positively sure about the Panasonic battery is 390 CCA on the MT FRS. It said it right on the top of it.

I meant about the AT being higher CCA. I know the MT is 390 like you said and wondered what battery the mt had and if it was the same one or different

I have a battery charger from Stanley 450 AMP.......


How do I use that... If I clip positive to positive and negative to negative.. wait 5 min and start the car... it does the clicking sound.

bat charger is full....

lol

What you have is likely a Jump starter that is intended for just starting the car, not charging the battery. If common batteries could be fully charged that fast we could have a lot more electric cars. If it is fully charged (and the switch to ON of course), you should be able to hook it to the terminals and start it up. No waiting 5 minutes. I would check the terminals of the jumper and see what kind of voltage you have. If the voltage looks good, and you are still not cranking, you could have something other than the battery keeping you from starting.

Yes exactly. It's a 12V, 450 AMP. It should just help start the car not charge the battery.

I have an extra security installed, I think it might be refusing the car to start. Though, I don't think it's the main reason. Since putting the key in overwrites the security.

So I really don't know. Am I suppose to try starting the car 5 times in a row for a period of 3 seconds?

Hey @Mikeez , is your car in a garage that is above freezing? If not you may have a bigger issue if you have had temperatures like ours the last couple of weeks. A dead battery can freeze. Anybody that has ever tried to boost a frozen battery can support me in the fact that the results can not be pretty. If your car is outside or in an unheated garage you may very well be frozen by now.

I have a automatic transmission and the battery is 390 cca Panasonic and had to replace it a week ago.

I got to start the car with a 1500 amp power pack

My garage is not heated, but it is always around the freezing point.

How old is the batter?

For all of you using these high cranking jump systems to start your car with a dead battery: IF you "quick jump" a dead car then leave the car to charge the battery all by itself, get ready to buy a new alternator.

Alternators are not designed to charge a dead battery.
You might get away with it once or twice, but it is definitely something you are told to NOT do by the alternator manufacturer.

If you have a completely dead battery, you should disconnect it from the car (make sure it is NOT frozen) and trickle charge it at a low amp rate (2amps) for 30 hours before hooking it back up.
60 Amp-hour battery => 2 Amps * 30 hours = 60 Amp-hours

I bought the car in June when they first came out so it's a 2013 model

Why do you want to get it to the 60 Ah? You're saying we should not jump the car with high cranking amps systems?

You've not changed the battery since then? Check battery acid level, =p

I don't have the old battery anymore, turned it in for a $12 core refund but it looked good when I checked the level though.

You dont HAVE to, but since youve gone through all the trouble, why not?

If the battery is just a little too dead too start the car, then a jump is ok.
Even being the source for the jumpstart can stress an alternator if the car being jumped is totally dead.

If the battery is completely dead, (nothing even clicks) then it should be charged by something other than the car.

ANd IF you have a monster alternator that can output a kajillion amps, then it would stress the battery to charge it from completely dead.

Haha alright my friend, good for you. Good luck with future projects :D

Alright, I get what you were trying to say. Thanks for the information buddy.

My car sat for about three weeks outside before the battery died - as in dead dead, couldn't even unlock the doors from the remote - and there were days where we didn't get above 20*F and nights that were near 0, so I'm not terribly surprised. I swapped in an older Odyssey PC680 last night (not ideal, only 170CCA) as a temporary measure until I pick up a Shorai LFX36L3-BS12 (540cca). This car isn't a daily and will be connected to a maintainer, so the LiFEPO battery should be up to the task.

hmm this dead battery issue happened to me too. The battery was flat out super dead after 3 days sitting around. Everything is stock and there are not installs to the electrical in anyway. All I did was plug in the ODBII reader to check out the reader works, unplugged the reader, then left the car sitting for the 3 days. No signs that the interior lights were left on.

dead battery?

Its totaled. Better find a new ride OP.

I accidentally left on my cabin light, and it drained the battery overnight. The battery was reading about 9 volts the next day; electric doors and lights were not functional.

I thought it was odd that running a small cabin light overnight would kill the battery, and I did drive the car that day (it wasn't just sitting for days). I ended up replacing it with a Duralast Gold battery from Autozone, figuring that it would be more reliable than recharging the factory battery.

Replace your inside light bulb by a led one !

The other thing i found out is that most of these modern switch-mode fancy computerized battery chargers wont start charging a completely flattened battery . Even one's that say they will charge flat battery's seem to fail to detect a dead flat battery connected to them ie terminal volts close to zero.

On two occasions I have had to revert to my trusty old transformer type battery charger I built in college to charge peoples completely flat battery's. Once they get a bit of charge in the battery the new fangled fancy ones will work .

I'm sure this results in people throwing away batterys that could be revived.

modern battery's often go completely open circuit when they fail, jump starting a car with an open circuit battery may cause issues as a working battery acts as a large capacitor smoothing transient voltages in the vehicle.

I just witnessed this yesterday.
I plugged in a cheap transformer based charger (NOT a maintenance trickle charger) to my granddaughter's car that had been sitting for almost a year with a dead battery.
The charger said "OK" when you first plugged it in and it didn't appear to be charging at all.
I left it on a 2 amp manual charge and will see if it ever began charging after 24 hours.


If that doesn't work, another trick is to hook up the charger, then jump another charged battery to the dead battery.
The charger will see this and begin charging.
Then you can disconnect the good battery and most of the time the charger will continue charging the dead battery.
PITA, but it usually works.