quick question ; should a fully charged battery sat indoors not connected to anything hold its charge and for how long , i know it depends on age and condition , but i have a a bosch s3 004 bought this time last year and twice now it has been flat , i took it back to euro parts where they charged and tested it saying it was ok , since 16.00 hrs yesterday it has dropped by 0.12 volts so i will keep it indoors and to check it , What do you think ?
It should hold its charge well if not connected - for months. It is normal for the Voltage to drop off a bit shortly after charging though. My experience with batteries is that they can show 'strong' on a charger, but still be poor at holding charge / working properly. Did they actually load test the battery when you took it back? Anything else is meaningless.
They connected it to a gizmo and the display read. "good battery " with an charge display that showed full
All batteries "self -discharge" over time, but I'm not sure how much a daily voltage drop you should expect. Somewhere on here there's a reference to batteries self-discharging at a faster rate if left on a concrete floor. No idea if this is true though, or why.
Self discharge rate: very reliant on the age of the battery, sediments across the bottom of the cells or the chemical state of the electrolyte. ..0.2% to 1% of the battery Ah capacity per day. Depending on the age of the battery. Not that I've ever tried to work it out ) Concrete floor insulating from: low temperature can reduce a batteries capacity for work by up to 40% @ 0'C so I guess if the air temp is marginaly higher than that of the surface of a concrete floor then a little bit of insulation might help a little. One little thing I came across the other day...as the temp falls the S.G rises which means a hydrometer test can give the reading of a fully charged cell whereas if the figure was corrected for temperature it would really be discharged. A good reason for load testing if a battery is suspected of being faulty.
i wonder whether alot of these batterys have been kicking around for years and arnt exactly tip top when you get um ,steps back and waits to be shot down . Its definately cold weather syndrome at the mo and we do tend to expect probably too much ,especially if we dont use them as a daily. Trubs with our batterys and leisure batterys is they only probably get used to capacity once in a blue moon unless you do blackpool illuminations with it in the cold alot.Normally if im on longer trip i have hook up anyway :-. This weather is really weird sunny no snow here ,20 miles down road in sandwich its snowing hard :-
An interesting point Barney as its usual practice to buy a battery already filled and charged. At a guess the ready to roll system came in when low maintenance semi sealed batteries became common. I used to buy Oldham from the local undertaker who filled them up at point of purchase. Of course it was a bit of a pain not being able to use them straight away but they did have a long life.
