Flat battery - OK to jump start?

[yeti]

As above, hadn't driven it in a while and then it was olny nipping to work and back. Net result is that the battery is utterly dead, not even an alarm, interior light or window movement. Properly dead

I can take it to Bucks with me tonight for a decent run so am preparing to jump start it this evening. Firstly, can I jump start it? Jumping my DB7 caused the gearbox ECU to blow a few years back so I'm wary now.

It's an 06 DB9 with the battery terminal under the bonnet. Anywhere I need to avoid putting the earth lead on?

[yeti]

Just had a call from Rick, all sorted

I would not have known to press the battery reset switch whilst the two batteries were connected up, so Rick has saved me a visit from the RAC, a probably tow on a low loader and all for no reason. DMS come up trumps again

Edited by yeti on Wednesday 31st August 15:23

[Shmee]

It's really weird, I actually want my car to get older so that I can take it to Rick for things!

[SoCalBrit]

What did the reset button do? When the battery died on my DB9 the portable jump-battery carried by AAA wasn't man enough to turn over the engine, so I had to flatbed it anyway.

[yeti]

SoCalBrit said:

What did the reset button do? When the battery died on my DB9 the portable jump-battery carried by AAA wasn't man enough to turn over the engine, so I had to flatbed it anyway.

Haven't done it yet! Rick says the battery cut-off comes in automatically when the battery gets low so it won't be completely dead - obviously need to reconnect the battery via the cut off or none of the power is getting to the battery! Hoping the Alfa's battery will be up to the job, it's the 3.2 V6 and car will be running so should have the crank amps. If not, then will try the Land Rover!

[SoCalBrit]

Ha, good luck. You might need both...

[brakedwell]

I suggest you read the Owner's Manual before you try the jump start. The DB9 manual says once started run the engine for 15-20 minutes, shut it down, re-start and take the car for a charging run (30 miles).

[watchrabbit]

I can tell you that a BMW 520d was not up to starting the 12 cyl. Good luck, I would try with the Range first, but as someone said, you might need both of them :-). I heard people saying that even the Range is sometimes not powerful enough for that...

[Jockman]

yeti said:

Haven't done it yet! Rick says the battery cut-off comes in automatically when the battery gets low so it won't be completely dead - obviously need to reconnect the battery via the cut off or none of the power is getting to the battery! Hoping the Alfa's battery will be up to the job, it's the 3.2 V6 and car will be running so should have the crank amps. If not, then will try the Land Rover!

So the BDS activates itself before it runs out. Thereafter, if you don't switch it back then recharging is ineffective?

Thanks for the heads up Yeti

[yeti]

Jockman said:

So the BDS activates itself before it runs out. Thereafter, if you don't switch it back then recharging is ineffective?

Thanks for the heads up Yeti

That was Ricks's info... makes sense!

Alfa not up to job so spent the day in that instead and missed the lovely weather today. Will be trying again with the Landy in the morning and get it to Nicholas Mee's for some interior bits and bobs. I'll leave it with them for the day and hopefully get a trickle charge from them while they have it.

[yeti]

brakedwell said:

I suggest you read the Owner's Manual before you try the jump start. The DB9 manual says once started run the engine for 15-20 minutes, shut it down, re-start and take the car for a charging run (30 miles).

Would this be the onwers manual in the elctronically controlled glovebox? It might be in the boot actually, but either way, I can't get at it.

Thanks for the info on the sequence, appreciated! Any info why that is required?

[brakedwell]

It doesn't say, but my guess is that it resets some of the systems that were shut down to protect the battery from damage when the voltage dropped below a certain level.

[Jockman]

yeti said:

Would this be the onwers manual in the elctronically controlled glovebox? It might be in the boot actually, but either way, I can't get at it.

Thanks for the info on the sequence, appreciated! Any info why that is required?

No, the Manual does not say why, but it assumes that after 20 mins of charging from a suitable 'donor vehicle' that there is sufficient charge to start the engine without assistance.

That is what my Manual says...you know...the one that I always keep outside the glovebox.

I would venture that it would be a brave man that turned off the engine shortly after retaining a charge, and especially before doing the 30 mile drive

[mikey k]

Jockman said:

So the BDS activates itself before it runs out. Thereafter, if you don't switch it back then recharging is ineffective?

Thanks for the heads up Yeti

Not quite, you can charge it with the BDS in either from the points under the bonnet or direct on the battery.

[rick-derby-]

the jump point under the bonnet when the bds has been activated is disconnected from the battery

voltage before pressing bds switch



after bds pressed



for charging purposes best to use the dedicated charge point in the boot,

[mikey k]

Doh!
Got it the wrong way round, should have remembered that from when I had electrical gremlins.

[yeti]

watchrabbit said:

I can tell you that a BMW 520d was not up to starting the 12 cyl. Good luck, I would try with the Range first, but as someone said, you might need both of them :-). I heard people saying that even the Range is sometimes not powerful enough for that...

Woohoo, Land Rover did the trick, there's a reason they're the best Car been running almost 15mins now, almost time for the switch off and restart. *gulp*

Fingers crossed...

Edited to add - all sorted now, many thanks to Rick without whom the car would still be say there in the dark covered in cat hair (from a moggy living on borrowed time).

Edited by yeti on Friday 2nd September 11:57

[rick-derby-]

this is why people can have problems with jump starting,as you are only useing the power from the donor car,

The way i would do it,

1.connect all leads first, positive to the jump point and the earth to a suitable bracket such as the alternator mounting
2.if the car has a reconnect switch( db9 yellow button under rear seat base, vanquish v8 vantage in a small hole in vertical panel behind drivers seat) press the button, if your car does not have the reconnect switch depends on year turn the ignition on and then off again,
3,have the donor vehicle running and preferably increase the revs to around 1500,and leave it like this for at least 10 minutes keeping an eye on the donor vehicles temperature
4, at this point try starting the car and once running just let it tick over but do not disconnect the jump leads yet leave these on for a further 5 to 10 minutes
5. disconnect the leads earth first and take her for a good run preferably with as little electrical load as possible, where practical keeping such as wipers and lights off

Also do not forget if carrying out this procedure in an enclosed space exhaust fumes can be deadly, also charging the battery from the point in the boot is much more preferable to jump starting as there is a small risk of damaging ecu's

[mikey k]

And don't forget to use the trickle charger

[GerryS]

I just had the same thing happen to my DB9.

Pressed BDS before departure for a 3 and a half week holiday
Battery totally dead on my return, not so

Called RAC, booster pack used to turn engine over after pressing the reset switch under the rear seat cover, no joy. Spoke to my local dealer who thought the fuel shut-off switch might have kicked in and might need resetting; locked and unlocked the car twice, tried again, engine turning over but nothing else

So, decided to leave it on charge for the rest of the afternoon/evening via the points in the engine bay and then called Aston Assistance who sent someone out the next day. Started up without any hesitation (just threw up and an emission error code which was later cancelled). The “AA” chap (who actually seemed very knowledgeable) checked the battery and also hooked up his laptop up to confirm all OK. Appears to be the tracker drawing power even when then BDS is active. I do have the battery conditioner but just didn't want to leave it plugged in unattended for that long
Driving beautifully at the moment

HAGWE

Gerry