new 8v gti problems. helo needed asap

[dan_thevdub_man]

hi guys.  I recently bought a 1996 mk3 gti 8v 2.0. had various work done to it.  piccs to follow shortly. im having trouble starting it of it has been stood for a day.  as if the batery wont hold its charge.  once its jumped, driven forkabit...if I turn engine off ot starts first time, could this be  battery issue. if so...wht battery shud I go for. and how would i install it without Interrptingnf immobiliser etc.
 thanks in advance
dan

[Gavv8]

I'd start by replacing the battery, the cold weather puts extra strain on it anyway.

[itavaltalainen]

before buying a new battery test that the alternator chucks out 14v with lights etc off and engine running. no point in buying a new battery if you don't test that first, as if alternator regulator is done a new battery won't be much joy for long.

got a varta battery for sale if need be (will go cheap)... it's a spare that is just sitting in my shelf, about 1.5 yrs old.

[dan_thevdub_man]

thanks for your help. im going test alternator later.
if it is the battery. are the difficult to replace? I have an aftermarket cobra immobiliser

[itavaltalainen]

battery is easy swap. you need a 10mm for terminals and i think 13mm socket for bracket.
might have to turn the bracket upside down since the base of new batteries is different and would otherwise wobble about when you turn...