flat battery

[SEACAP]

Stupidly yesterday i was doing something in the car and left the ignition on which ran down the battery. I'm gonna charge it back up tomorrow but just wanna check ...   can i just put the battery charger straight on to the terminals and charge it with out frying or damaging anything ?  or do I haver to remove the battery and then charge it ?  Can i just use the boost and start the engine (then letting it charge) will this cause any problems ?    Just wanted to check....you never know with modern cars.   Thanks

[Phil mcavity]

if i were you, id jump start it with another car, then take it out for an hour drive to recharge it, safest way, good excuse to give it the beans in a high gear on the motorway to recharge it.Regulator in the alternator will give it a good boost as it senses battery level voltage and regulates the ammount of charge to be sent to the battery.

[SEACAP]

Magic....thanks phil. 

[bacillus]

it very much depends on what type of charger you have.

if it's one from somewhere like Halfords then you have to remove the negative terminal before you start charging to avoid damaging the alternator. If you have one of the modern smart chargers like the Carcoon Power and Charge unit or the ctek multi xs 3600 smart charger then just start charging with the terminals still attached.

[Top Cat]

Seacap expect lots fault lights when you start it some one correct me if im wrong but i think they reset themselves after a while.

[Phil mcavity]

yes it may do, but should reset with a minute of restarting. As many rev's as possible to help charge the battery, run in 3rd around town or 4th on the motorway to help regulater boost battery faster. I wouldnt disconnect battery or you may need to recode radio etc. quicker and easier to jump it with another car without risking getting your hands dirty.

use this method if you dont know which end of a spanner to use, or simply use a 10mm socket or 13mm socket (not sure which one) to undo battery base clamps, then remove negative terminal 1st so you do risk arking your spanner with the cars bodywork (ie lots of sparks).

Remove battery to charge, charge for around 2 hours, replace battery putting positive terminal on 1st so you dont spark yourself out incase you touch + and - .

much easier to do first method without getting your hands dirty.

[Greenouse]

Surely the safest way is to remove the battery and charge it?? Will only take a few minutes after all to take off, but a big risk if you don't! 

[2007GTI]

you wont need to recode the radio as the ECU remembers the radio once installed the first time, if its OEM.

[RedRobin]

if i were you, id jump start it with another car,

....No! No! No!! According to VW Assist / RAC VW specialist roadside mechanics, you should NEVER jump start the Mk5 Golf! There is a risk of damage. Don't ask me why, but I was surprised and have remembered it.

[Phil mcavity]

odd, but would be interesting to know why a mk5 engine is different to any other engine???