12voltpower
Submitted: Monday, Feb 24, 2014 at 07:40
ThreadID:
106391
Views:
2212
Replies:
3
FollowUps:
3
This Thread has been Archived
johno59
Can anyone tell me why the voltage in A 12volt DC goes up in the morning after all appliances have been turned off the night
before. Thanks johno
Reply By: Member - John and Val - Monday, Feb 24, 2014 at 09:25
Monday, Feb 24, 2014 at 09:25
Johno,
A 12V battery actually has an internal voltage of about 12.6V, or a bit higher. This voltage is determined by the chemistry of the particular battery.
When current is drawn from the battery, losses occur both within the battery and in the external wiring, so the measured voltage will be lower than the nominal internal voltage. This effect is also present for some time after the current flow ceases. In the morning after the system has had time to equalise with no loading overnight your measurement will be very close to the actual internal battery voltage. So..... you aren't actually seeing a higher voltage in the morning -- it's just that you saw a lower voltage the night before when the system was in use! (Of course if you have some solar panels feeding in, you'll see a higher voltage in daylight than you will at night too, for obvious reasons!)
Cheers
John | J and V
"Not everything that can be counted counts, and not everything that counts can be counted."
- Albert Einstein
Lifetime Member My Profile My Blog Send Message |
AnswerID:
527112
Follow Up By: Allan B (Member, SunCoast) - Monday, Feb 24, 2014 at 09:57
Monday, Feb 24, 2014 at 09:57
In a nutshell
John.
FollowupID:
809511