Eugene's DIY Den Posted yesterday at 20:39 Posted yesterday at 20:39 (edited) I’m after putting a new 12 V, 7 AH lead acid battery into my alarm panel. Off load voltage was 12.9 V at the battery terminals before fitting. A fully charged 12 V battery should read around 12.8 V. When I did a load test, with the panel and sensors pulling 0.55 A, the voltage eventually dropped to 12.0 V before I stopped the test after a few minutes (the voltage fell faster at first). Float charge voltage for a lead acid battery (and from a panel) is typically 13.8 V. So just wondering since the battery isn't charged in a three state mode by a panel like a normal charger would charge it (constant current, constant voltage and then trickle maintenance charge), how long typically does it take a new battery to fully charge? I've seen figures of 24 to 48 hours mentioned. Edited yesterday at 20:39 by Eugene's DIY Den Quote Talking Tools, a Facebook group for discussing anything tool/DIY related.
Eugene's DIY Den Posted yesterday at 20:41 Author Posted yesterday at 20:41 (edited) I'll see if I can find some charge/discharge curves. Presumably if the battery was sitting on a shelf in a store, it may have self-discharged somewhat. Not sure what the self-discharge rate is for lead acid, but 12.9 V would have indicated that it was fully charged, but maybe not. I guess there's some variability. The panel is trickle charging it at 22 mA. That figure was 38 mA for the 6 year old battery (which I thought was a Yuasa, but it was an Interlogix. I presume these are just badged and there are a limited number of battery manufacturers) Edited yesterday at 20:44 by Eugene's DIY Den Quote Talking Tools, a Facebook group for discussing anything tool/DIY related.
ian.cant Posted yesterday at 21:13 Posted yesterday at 21:13 Two things of note here, if your panel is pulling over half an amp quiescent that seems quite high to me and also if your new battery is dropping to 12v under load I would suggest its not a good battery. 1 Quote
PeterJames Posted 10 hours ago Posted 10 hours ago 13 hours ago, ian.cant said: Two things of note here, if your panel is pulling over half an amp quiescent that seems quite high to me and also if your new battery is dropping to 12v under load I would suggest its not a good battery. He said 55mA not 550mA Quote
ian.cant Posted 1 hour ago Posted 1 hour ago 9 hours ago, PeterJames said: He said 55mA not 550mA 23 hours ago, Eugene's DIY Den said: with the panel and sensors pulling 0.55 A, Thats half an amp in my book 1 Quote
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