Martin, Hi. 28 mA is 28 thousandths of an amp i.e. 0.028 Amp. Flowing each hour for a week is 24x7= 168 hours. So you have 0.028 x 168 = 4.704 Amp Hours used up by that item for your battery. Around 10 to 15% of a usual battery charge depending on battery size.
A battery sitting there doing nothing can be expected to loose around 10% charge in a month. So a week is fine from that point of view also. My Q battery is 40 Amp Hours, so going by that if fully charged even a poor battery should be OK. Is that the only drain on the battery? If so, don't worry - just don't leave the lights on.............. Regards Derek On 5 Aug 2009, at 19:36, Susan and Martin Scott wrote: > > I was thinking in terms of battery drain when unable to charge eg if > I leave > the car for week at the airport whilst on holiday. > How long would it take for 28mA to drain the battery down to 50% or > 12.2V > for instance? Sorry but whilst I'm able to understand simple > circuits I'm > not an 'eleectronics' man. > > > > ----- Original Message ----- > From: "Derek Clews" <[email protected]> > To: <[email protected]> > Sent: Wednesday, August 05, 2009 3:10 PM > Subject: [Quantum Owners] Re: Battery Drain > > > > My handy text on batteries quotes: > > 12V batteries > 100% Charge 12.6V > 75% 12.4V > 50% 12.2V > 25% 12.0V > 0% Flat 11.7V > > This is Voltage across the terminals at rest (not under and load or 2 > seconds after charging, so disconnect for a while if in doubt) with a > multimeter. i.e. the kind of test we can all do. I have found it to > be a good rule of thumb in practice. Of course, as they get older > batteries fail to hold charge so well and need replacing in time. But > a well used battery can last many times the life of a miss-used > battery. > > I use a multistage regulated charger for permanent attachment during > storage. I have a Ctec 3600 that has worked well for me for years and > is totally switch on and forget. There are bigger and smaller ones. > > Demon Tweeks does them with 10% discount for members: > http://www.demon-tweeks.co.uk/products/search.asp?keyword=battery+charger&classCode=MSPORT&brandCode=all&x=23&y=15&page=4&filterBrandCode=B131&OrderBy= > > Either that or run the car for half an hour plus every week, if you > don't want to say 'bye bye battery'. > > Derek > > > > > On 5 Aug 2009, at 14:35, Jim Hearne wrote: > >> >> That was the answer, it depends how quickly and easily the car >> starts. >> >> I'd guess, if the battery is reading below about 9 volts before you >> try >> to start the car it's not going to make it. >> >> Jim >> >> Susan and Martin Scott wrote: >>> My very question - how much is almost flat! >> >> >>> > > > > > > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Quantum Owners Group" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/quantumowners?hl=en IMPORTANT NOTE: All information presented herewith is provided on an "As Is" basis, without warranty or the implication thereof. Neither the Quantum Owners Club nor the individuals associated with the Quantum Owners Club or in the preparation of the above information shall have any liability to any person or entity with respect to liability, loss, or damage caused or alleged to be caused directly or indirectly by the instructions contained within this or related message(s). -~----------~----~----~----~------~----~------~--~---
