My latest bargain from Maplins.

[MasterofHera]

Just received my battery booster £19.99 marked down from £39.99 looks same as the swindleries are selling for £49.99. 17Ah battery...900amps peak...400amps boost starting. In the instructions states connect earth cable to ground NOT to earth terminal on battery. Anyone know why? Have used other batteries connected direct to battery terminals for starting in the past with no ill effects.

 

[Tekkie]

This is to prevent any spark Igniting any Hydrogen gas venting from the Battery. As you usually connect the +ve terminal first followed by the -ve.

 

[mortehoe]

!!!!!!!!!!!!!!!!!!!!!!!

It's the excatly the same as the $4.99 from ....... U know who ....You've not only been ripped off, but have been ripped of because you are a punter!

Think about Axminster ..................

 

[MasterofHera]

Re: !!!!!!!!!!!!!!!!!!!!!!!

Thanks Brian suppose they are just playing safe. Mortehoe having spent most of my life as a "grease monkey" I know a good piece of kit when I see it.
Mike

 

[clyst]

Plus the fact if the reason for using the booster is because the battery is flat the power in the booster will try to "charge" the flat battery ----If you see what i mean .

 

[Strathglass]

One of the reasons for puting the negative lead on the engine block rather than the battery is because it shortens the length of the electrical path between the booster battery and the starter.
It effectively by-passes the voltage drop in the negative lead between. the vehicle/boat battery and the engine block
This gives a higher voltage/current to the starter from the booster battery when trying to start the engine.

Iain

 

[VicS]

[ QUOTE ]
One of the reasons for puting the negative lead on the engine block rather than the battery is because it shortens the length of the electrical path between the booster battery and the starter

[/ QUOTE ] Its a minor reason. The real reason is as already stated to make the last connection well away from the battery to avoid the chance of a spark igniting any hydrogen. That should be the first connection removed when disconnecting for the same reason, in fact there is a much greater risk of creating a spark when disconnecting.

The chances of igniting any hydrogen are small but it does happen and the consequences of a battery exploding in ones face could be very serious. There is little or no trouble involved in making that last connection away from the battery so common sense and a balanced risk assessment says that's the way to do it.

 

[pappaecho]

I was in marina in Spain, when a boat went up after the batteries were charged overnight and gassing ... not much left afterwards ... so take this threat seriously