smart fails to cold start

[24-42]

Originally Posted by jwight

Good news - about an hour on the charger and it fired right up; my guess is it was just below the trigger voltage needed to start everything up. Took it out for a longish run to the store and it started fine again, so it's getting another night outside.

Donald, this battery is about a year old (01/08 build date) and with any other car that wouldn't call for changing the battery. Surely they don't have to replace the battery after a year in Canada, Sweden or Norway?

We'll see what happens tomorrow.

jwight;

When the car wouldn't start, did the engine turn over (albeit slowly) or would it not even do that ?

If the engine turned over, THERE WAS NOT ENOUGH AMPERES AVAILABLE. The starter will take ALL that it needs and the ignition gets what is left over(IF ANY). (simplified explanation).

Donald LaFavor

[jetfuel]

[quote=24-42;187257(It is serrated and has a larger surface for electrical conductivity. Scratching away the paint on the floor away from an area around the
[/quote]

...if this is the way of the OEM then I will suggest to inspect the ground for security and remove all traces of paint to provide the best grounding possible...

jetfuel

[chieftmc]

Originally Posted by 24-42

I found that the posts are reversed from OEM, however Mercedes provides for either post pattern.

PLUS post: Long enough to reach.

NEGATIVE post: There is a stud protruding from the floor at each end of the battery box. For the 34/78, just move the NEG cable from the stud (10mm nut) to the protruding stud on the floor at the other end of the battery box. Be sure to place the wider flat side of the nut down (It is serrated and has a larger surface for electrical conductivity. Scratching away the paint on the floor away from an area around the post (the size of the terminal) will also assure a good electrical connection.

Batt Hold down: No modification necessary.

Batt Vent: No Batt vent necessary ( You may plug hole in the bottom of the battery box) The Optima is COMPLETELY sealed. NO GASSING !

QUESTIONS ?

Donald LaFavor

Thanks Don,
Exactly the info I was looking for

[24-42]

Originally Posted by jetfuel

...if this is the way of the OEM then I will suggest to inspect the ground for security and remove all traces of paint to provide the best grounding possible...

jetfuel

Can't hurt...... Can help.

Many, many, many Mfgs have had this problem going a long way back.

Toyotas were painted by bath. A small loose leaf shape stickem was put on every grounding post or screw hole(we hoped) and after painting it was removed when attaching ground wire.

Donald LaFavor

[jwight]

Originally Posted by 24-42

jwight;

When the car wouldn't start, did the engine turn over (albeit slowly) or would it not even do that ?

If the engine turned over, THERE WAS NOT ENOUGH AMPERES AVAILABLE. The starter will take ALL that it needs and the ignition gets what is left over(IF ANY). (simplified explanation).

Donald LaFavor

In the video, the engine turned over and almost caught once; other times there was some clicking and then the car shut down (computer turned it off is my guess.)

[jetfuel]

...big Q here...does the fuel pump runs 'til it pressurizes the rails or starts to run when it sees crank rotation?....

jetfuel

[jefferios]

jw, can we expect a video of tomorrow's test?!?

I'm pretty confident that it'll start tomorrow, if it doesn't something may be fishy with the battery.

[Godfather]

Actually, the car heard somewhere it was going to be traded in on a hybrid. Then it got left out in the cold. Does anyone really wonder why it didn't start? Would you? (LOL)

[24-42]

Originally Posted by jwight

In the video, the engine turned over and almost caught once; other times there was some clicking and then the car shut down (computer turned it off is my guess.)

The first time the engine 'Clicks', GIVE UP ! There is not enough current to rotate the starter motor.

IMO: the stock battery does NOT have enough reserve for a really cold winter.

Ampere-hours (A·h) is the product of the time that a battery can deliver a certain amount of current (in hours) times that current (in amperes), for a particular discharge period. This is one indication of the total amount of charge a battery is able to store and deliver at its rated voltage. This rating is rarely stated for automotive batteries.

Cranking amperes (CA), also sometimes referred to as marine cranking amperes (MCA), is the amount of current a battery can provide at 32 °F (0 °C). The rating is defined as the number of amperes a lead-acid battery at that temperature can deliver for 30 seconds and maintain at least 1.2 volts per cell (7.2 volts for a 12 volt battery).

Cold cranking amperes (CCA) is the amount of current a battery can provide at 0 °F (−18 °C). The rating is defined as the current a lead-acid battery at that temperature can deliver for 30 seconds and maintain at least 1.2 volts per cell (7.2 volts for a 12-volt battery). It is a more demanding test than those at higher temperatures.

Ask yourself, how close (at the present) is my battery to 100% at 70deg ?

I know of many repair shops in Detroit that sold new batteries with exchange in the winter and then sell the trade-in as a used battery the following summer.

Donald LaFavor

[jetfuel]

...Donald...do you know the answer to my fuel pump question?

jetfuel