Jump Starting

[minky9717]

Ahhhhhhh!!!!!!!

I jump started successfully last night. Ran for Half an hour.

Went out to see this morning and battery flat again.

Must be a drain somewhere. Any ideas or general drains people know of?

[wonkanoby]

some radios by aldi

how olds the battery

[minky9717]

The Battery looks fairly new (ish) very clean Bosh.

After market radio is a JVC that doesnt appear to be on

[Bob]

If the battery was completely flat it may be fubared, even if brand new.

[cmm303]

Ahhhhhhh!!!!!!!

I jump started successfully last night. Ran for Half an hour.

Went out to see this morning and battery flat again.

Must be a drain somewhere. Any ideas or general drains people know of?

Next time, disconnect battery before going to bed. If flat again in the morning it is time to treat Bongo to a new one.

A completely flat battery will take longer than 1/2 hour to fully recharge but probably enough at this warmer time of year for a morning start with a decent battery. Before condemning the battery best check that it is actually being charged when the engine is running - voltage should be well over 13v quite quickly.

[wonkanoby]

can you measure the milli amp drain on battery when ignition is off

adso just of late dab powered ariels have also been to blame

[minky9717]

I have just attached a multimeter to Neg Post on Battery and Neg lead on Battery (disconnected) and getting a reading of 2.35 MA

[Simon Jones]

That's nothing to worry about. Check the voltage across the battery now with it disconnected and then again in the morning. If its dropped by more than a few tens of mV then it's probably knackered. The Bosch S4 range of batteries have a 4 year warranty so as long as you have proof of purchase you ought to be able to get it replaced.

[minky9717]

Thanks for all the help. I currently have it charging via mains. Going to get it full and then see what happens.

If it drops, then so does the bank account for a new battery

Thanks again all

[nth]

Hi NTH,

I was always taught never to go direct to battery for fear of sparking etc.

I was taught the same, however I the real world the best connection is directly on the terminal, I jump start cars almost every day of the week (with a spike protected jump pack most of the time to be fair) I have never been blown up yet or had any problems doing it this way, never heard of anyone else being blown up either. Cars with battery monitoring systems however should never be jump started using the negative terminal as it can cause smart charging systems to operate incorrectly. Most cars with BMS normally have a specific jump start points. Some types of cars (eg modern Mercedes) have very specific procedures for jump starting them, not doing it correctly can damage the (very expensive) SAM unit.

[cmm303]

Hi NTH,

I was always taught never to go direct to battery for fear of sparking etc.

I was taught the same, however I the real world the best connection is directly on the terminal, I jump start cars almost every day of the week (with a spike protected jump pack most of the time to be fair) I have never been blown up yet or had any problems doing it this way, never heard of anyone else being blown up either. Cars with battery monitoring systems however should never be jump started using the negative terminal as it can cause smart charging systems to operate incorrectly. Most cars with BMS normally have a specific jump start points. Some types of cars (eg modern Mercedes) have very specific procedures for jump starting them, not doing it correctly can damage the (very expensive) SAM unit.

i would not know a BMS if it hit me in the face. Do cars with these have clear warnings under the bonnet or is this down to expertise? Also do the same rules apply to the donor vehicle?

[nth]

i would not know a BMS if it hit me in the face. Do cars with these have clear warnings under the bonnet or is this down to expertise? Also do the same rules apply to the donor vehicle?

BMS systems are normally identified by a little sensor module on the negative terminal like in the pics below

Some manufacturers like Vauxhall have a separate sensor clipped round the negative cable like this one

You may find warning stickers on the terminal cover on some cars with a pic of a jump lead croc clip with a cross through it. BMS systems have been around for a good few years now and if the car is fitted with stop/start it will almost certainly have a BMS system.
It shouldn't matter if the neg terminal is used on the donor car as the battery is charged & the charging system is working.

[cmm303]

i would not know a BMS if it hit me in the face. Do cars with these have clear warnings under the bonnet or is this down to expertise? Also do the same rules apply to the donor vehicle?

BMS systems are normally identified by a little sensor module on the negative terminal like in the pics below
...
It shouldn't matter if the neg terminal is used on the donor car as the battery is charged & the charging system is working.

Excellent. Thanks. Useful to know.
Always wondered what the gubbins was doing on the neg terminal on my car! Good thing the only jump start it has had was from a professional at Heathrow Airport! (yeh yeh, I left the courtesy light on after digging out the passports)

[mikeonb4c]

Here's a tip. Fit a beefy lb capable of coping with high discharges and carry some jump leads. If sb flat, give it 5 mins from lb, disconnect from lb then turn key. Got me out of trouble twice

[mikeWalsall]

I have one of these .. at less than a pound in weight it starts my 3.0 V6 Alphard up OK ..

http://www.ebay.co.uk/itm/251929575661? ... EBIDX%3AIT