Hi there. I am working on a basic 12V SLA battery "float" charger for an emergency power backup application. Works fine and everything, except for one little thing that's bugging me (yet it's probably very simple, but can't for the life of me come up with a solution).
I need a small "add-on" circuit that will warn me (perhaps with an LED) when/if the battery is disconnected from the charger. Possible scenarios:- Battery connection becomes loose; the fuse blows due to a short or incorrect polarity; or the 'Battery On/Off' switch is "Off") - otherwise there is no way of telling that the battery is connected or not.
I have thought about using the battery's internal resistance as a detection method, but I'm not sure how I would go about this, and its reliability.
What needs to be taken into consideration is that the battery may or may not be drawing current from the battery. Therefore, a 'current flow detector' may not work in this case.
I have attached a diagram explaining how the switch, fuse and diode are connected to the battery at the moment.
Voltage applied to battery = 13.5-13.8V
Current supplied to battery = <0.39A.
Battery = 12V SLA, 1.3Ah.
Any help on this matter will be much appreciated.![Smile :) :)](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
Jason.
I need a small "add-on" circuit that will warn me (perhaps with an LED) when/if the battery is disconnected from the charger. Possible scenarios:- Battery connection becomes loose; the fuse blows due to a short or incorrect polarity; or the 'Battery On/Off' switch is "Off") - otherwise there is no way of telling that the battery is connected or not.
I have thought about using the battery's internal resistance as a detection method, but I'm not sure how I would go about this, and its reliability.
What needs to be taken into consideration is that the battery may or may not be drawing current from the battery. Therefore, a 'current flow detector' may not work in this case.
I have attached a diagram explaining how the switch, fuse and diode are connected to the battery at the moment.
Voltage applied to battery = 13.5-13.8V
Current supplied to battery = <0.39A.
Battery = 12V SLA, 1.3Ah.
Any help on this matter will be much appreciated.
Jason.
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