I got a replacement Yuasa battery under guarantee after about 4 years, from Halfords, after a bit of a fight (not much, after the initial refusal, I just logged the voltage over a few days, charged it, and did the same again, to show how quickly it lost its charge - even when disconnected from the car).
But the replacement is now playing up after less than a year. It loses a fair bit of charge almost instantly, and then more gradually until it’s well below 12 volts. I’ve been monitoring it for about 4 weeks (connected and not) over 4 or 5 charges, so I’ll take the spreadsheet and graph back to Halfords next week.
On my first visit to Halfords, they tested the voltage, said it was 12 volts (after the drive into Grantham) and so hit was OK. I since checked on line about battery voltages - it’s not a linear relationship, but 12 volts is only 25% charged, 12.2 volts is 50%, 12.4 volts is 75% and over 12.7 is 100%. Anything below 12 volts is classed as ‘discharged’, but my car will start below this.
(Source: batterystuff.com)
So, you’ve only really got the range 12-13 volts or there abouts, to play with.
My alternator is charging at 14.2 volts, so I think that’s OK.
I’ll let you know how I get on.
__________________
2002 Final Edition S8. Ebony black with Silver Grey leather and myrtle wood trim. Current mods: solar sun roof, 20mm rear spacers, 15 mm on front, red brembo callipers, 6k headlights, rear view camera, engine remap, alloy dash dial rings, alloy navi rings, tt/phaeton pedal upgrade, (and custom matching foot rest) dension ipod interface & parrot hands free kit (both fully hidden), av input, tv in motion switched thro' PF switch in blanking plug right of steering column, Audi 'quattro' sill covers, repositioned centre console switches, radio clock, .
Planned mods: auto-dimming rear view mirror, dash cam (as steamship's), fit the ski hatch, refit philips drl's (or maybe not - nope, definitely not - horrible botch!).
|