Flat Battery-Safely jumpstart your Euro

[Monty77]

This has probably already been covered in the 'interesting bits inside your Euro' thread, but I can confirm that after approx. 1.5 hours of leaving your MY06 HID's on; yes they do automatically switch off due to lack of voltage!!! For some reason my wife did not hear the chime:confused: and went shopping with our toddler. The central locking wouldn't even work!!! I contacted our dealer service advisor with the question of jump-starting with an 'all ok', and the usual 'turn on the flat battery car's lights to prevent surges' response....It obviously had to be done to get the car home, but I'm just wondering if anyone has had any problems to look out for after the fact ie. ecu/idling/running etc, with a jump start or (roll start in a MT)?

[Chris_F]

I recently roll started my car after i left the keys in the ignition with the accessories running for too long. The car came back to life and theres been no problems since. Tho I'm looking into a new battery because i think mine has had better days being over 2 years old.

[aaronng]

They actually turned off because of insufficient voltage....
If the battery was run down flat, it will never be able to hold the same amount of charge again. Capacity is diminished everytime you run the battery to below 40% (I think that was the number) I recommend you get a new battery.

[yfin]

They actually turned off because of insufficient voltage....
If the battery was run down flat, it will never be able to hold the same amount of charge again. Capacity is diminished everytime you run the battery to below 40% (I think that was the number) I recommend you get a new battery.

My original battery is still cranking the same after 3 years (including an out of ordinary incident of being left completely flat for 4 weeks)!

The RSM shows the voltage as a-ok too (with the car turned off). I am surprised how durable the stock battery is. It might be too small for the vehicle but it will last.

[Monty77]

They actually turned off because of insufficient voltage....
If the battery was run down flat, it will never be able to hold the same amount of charge again. Capacity is diminished everytime you run the battery to below 40% (I think that was the number) I recommend you get a new battery.
Sorry...that's what I meant...insufficient voltage :o . The opti-tron (is that what it's called?) dash lights were flickering as well. :eek: ...and if they're only LED's, the batt voltage must have been pretty low! The HID's work fine again, I'm just hoping there is an under-voltage cut out circuit in them and no long term damage caused. (You would think the Honda Engineers have catered for all of this anyway;)

Cheers for your help...

[aaronng]

My original battery is still cranking the same after 3 years (including an out of ordinary incident of being left completely flat for 4 weeks)!

The RSM shows the voltage as a-ok too (with the car turned off). I am surprised how durable the stock battery is. It might be too small for the vehicle but it will last.

You have to measure the change in voltage when a load is put on it. Can the RSM show voltage, before and during the starting of your car? Dying batteries actually drop in voltage when a load is put on it.

[aaronng]

Sorry...that's what I meant...insufficient voltage :o . The opti-tron (is that what it's called?) dash lights were flickering as well. :eek: ...and if they're only LED's, the batt voltage must have been pretty low! The HID's work fine again, I'm just hoping there is an under-voltage cut out circuit in them and no long term damage caused. (You would think the Honda Engineers have catered for all of this anyway;)

Cheers for your help...
LEDs are finicky actually. If the voltage is even slightly too low, they won't work. Normal bulbs on the other hand work even with 10V eventhough they are spec'd for 12V.

Anyway, keep a lookout on your battery performance. If you notice that the battery doesn't hold charge anymore (difficult to start in the morning), then change the battery. Nothing is worse than having your wife stranded somewhere with a flat battery (ok, you wife with a flat tyre is a little worse).

[yfin]

You have to measure the change in voltage when a load is put on it. Can the RSM show voltage, before and during the starting of your car? Dying batteries actually drop in voltage when a load is put on it.

Nah, not quite - you need to connect directly with a multimeter etc to the battery to test the cranking load. The best I can do is read the volts when the car is not started for 24 hours (engine off). That gives me some indication as to whether the battery is fully charged. Not a guarantee of course but it is better than nothing.

[Tobster]

I recently roll started my car after i left the keys in the ignition with the accessories running for too long.

Maybe I'm just confused but I'd always been led to believe that you couldn't (or maybe it was shouldn't) roll start a fuel injected car? Unless it depends on how flat the battery is: what's going to power the engine management and injectors?

Something about stuffing injectors?

Anybody?

[Chris_F]

well the battery still ahd enough charge to roll down the windows and unluck the car it just didnt have enough charge to display the dash properly (flickering as the OP said)... it started up ok and ran perfectly fine after being roll started (in reverse i might ad lol)

[aaronng]

Nah, not quite - you need to connect directly with a multimeter etc to the battery to test the cranking load. The best I can do is read the volts when the car is not started for 24 hours (engine off). That gives me some indication as to whether the battery is fully charged. Not a guarantee of course but it is better than nothing.

Since I like sparks, I think I'll hold the multimeter to my battery and get someone to start the car. LOL :p

[aday]

Maybe I'm just confused but I'd always been led to believe that you couldn't (or maybe it was shouldn't) roll start a fuel injected car? Unless it depends on how flat the battery is: what's going to power the engine management and injectors?...

I believe the problem lies with push-starting cars with catalytic converters.

From http://www.tribuneindia.com/2005/20050917/saturday/motoring.htm:

"If you bump-start or push-start a car, the fuel pump will be activated before any of the systems begin to function. If the fuel pump is working, fuel which has not been fired up will flow into the exhaust system and into the catalytic converter. When the engine fires up, the excess fuel will catch fire and cause extensive damage to the catalytic converter."

[Chris_F]

ahhh crap....

hope that didnt happen to mine :P

[aday]

ahhh crap....

hope that didnt happen to mine :P

Don't stress. I think you would have noticed the bang and resultant flames. :p

[Chris_F]

lol that i would

[Monty77]

...Well, that could be one cheap (and nasty) way to get a higher flow out of your cat i guess... :cool: If you timed it right!!! hehehe. Thanks for the info guys!

[aaronng]

I believe the problem lies with push-starting cars with catalytic converters.

From http://www.tribuneindia.com/2005/20050917/saturday/motoring.htm:

"If you bump-start or push-start a car, the fuel pump will be activated before any of the systems begin to function. If the fuel pump is working, fuel which has not been fired up will flow into the exhaust system and into the catalytic converter. When the engine fires up, the excess fuel will catch fire and cause extensive damage to the catalytic converter."

In your car with a fully charged battery, when you turn your key to "ON", the fuel pump runs, but you don't get a bang in the cat. Why? Fuel injectors require electricity to spray and if you don't have power to your injectors, you don't get fuel in the cylinders.

Anyway, when your car is in gear and rolling, the engine will be turning and the alternator will be providing enough juice to run your car even with a flat battery.

[aaronng]

Maybe I'm just confused but I'd always been led to believe that you couldn't (or maybe it was shouldn't) roll start a fuel injected car? Unless it depends on how flat the battery is: what's going to power the engine management and injectors?

Something about stuffing injectors?

Anybody?
When in gear and rolling, your alternator provides the power to run everything. How do you think that your car is able to idle as well as charge the battery at the same time? The alternator provides for everything. Just make sure you turn off your A/C when push starting. If the compressor kicks in, the spike in the current draw can wear out your alternator.