Capacity Testing and 20 HR Rating
I'm thinking about doing a capacity test on my four GC2's. They have a 20hr rating of 215Ah. One thing I'm curious about is how the 20hr rating would have been determined. Being 6v, would they h...
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I loaded our RV's 200 amp hours of 8 1/2 year old 12 volt AGM batteries with an inverter powering a small hair dryer set on LOW. I used a ammeter to read about 20 amps coming out of the batteries with the hair dryer running. After 5 hours if this, I removed the inverter and let the battery bank sit for awhile with no load on them. I then used a voltmeter to read about 12.1 volts on the terminals.
I interpreted this as meaning that the batteries where still capable of being recharged to 200 amp hours ... since their half-capacity voltage reading of 12.1 volts occured after having supplied about one-half of their original 200 amp hours of capacity (5 hours times 20 amps equals 100 amp hours worth of capacity consumed by the hair dryer).
This was a simple capacity test, with the toughest part being inclusion of an ammeter to measure what amperage the load was drawing. No other pieces of equipment or special gauges or meters were required to determing the batteies' capacity capability. This type of test can be done as often as you like to keep aware of when it's time to consider fitting new batteries.
To make this kind of testing easy, I permanently installed an ammeter in the main negative lead of the RV's battery bank. Since we always carry a hair dryer and inverter with us, we can even perform this test when camping, anywhere, anytime.
If any of you experts find a hole in this method, please explain the problem .... thanks in advance. :@
I interpreted this as meaning that the batteries where still capable of being recharged to 200 amp hours ... since their half-capacity voltage reading of 12.1 volts occured after having supplied about one-half of their original 200 amp hours of capacity (5 hours times 20 amps equals 100 amp hours worth of capacity consumed by the hair dryer).
This was a simple capacity test, with the toughest part being inclusion of an ammeter to measure what amperage the load was drawing. No other pieces of equipment or special gauges or meters were required to determing the batteies' capacity capability. This type of test can be done as often as you like to keep aware of when it's time to consider fitting new batteries.
To make this kind of testing easy, I permanently installed an ammeter in the main negative lead of the RV's battery bank. Since we always carry a hair dryer and inverter with us, we can even perform this test when camping, anywhere, anytime.
If any of you experts find a hole in this method, please explain the problem .... thanks in advance. :@
