See also charging electronic devices.|
Charging 12 V backup batteries:
Most Gell Cell battery experts would probably tell you 13.6 V is about optimum for float charging a Lead Acid gell cell. Going to 14V or higher tends to shorten their lifespan by warming them excessively so that they "dry out" more quickly.
The charging current does not exceed 5-10% of the rated battery capacity (eg 10AH would be 1 Amp charge). (Deep Cycle Battery FAQ says max. of C/20 = 5% for gel cells) Leave on the supply until the current goes to .010 amp. or so...
A cheap way to measure current (Amps).
From a 13.8 V supply place a 10 -30 ohm 10 Watt resistor in series with the supply and battery. Do make sure with a voltmeter across the resistor (remember I = E/R) that . Also, do fuse the line between the battery and the supply (try a fuse equal to the battery capacity (10AH = 10 amps).
Batteries in Home & Garden.
Batteries in the products page Charging at Deep Cycle FAQ
LC1-12-1A - Leoch 12V / 1A SLA Battery Charger
Charging the lead-acid battery - Battery University
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The charge of the mobile phone brigade by Graeme Philipson
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Uninterruptible power supply
CTEK Multi US 3300 12V Smart Battery Charger Review
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