Thanks.. can I mitigate the higher floating v by running it down 50 % regularly and checking the water level
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UPS..has anyone built a home made one? If purchased what the best one for a 3ish hour power failure
- Thread starter kenora
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Heyho...
Lead acid batteries are not big fans of semi deep discharge...and 50% is already alot for them...
I would recommedn to see whatt he floating voltage is on yours (multimeter is your friend) and check papers for batteries what they recommend and then adjust UPS accordingly:
Changing the battery constant
Use hyperterminal (or telnet, or whatever) @ 2400 baud with 8-N-1 Xon/Xoff settings, under Advanced make sure FIFO is unchecked. There can not be any network cards in the UPS for this to work.
- Put the UPS in "Smart" mode by typing Shift-Y (capital Y) it should return "SM"
- Now put it in "Program" mode by typing "1", wait 2-3 secs and type "1" again. It should return "Prog"
NOTE: It is very easy to turn your UPS into a nonresponsive brick if you type in the wrong thing while in Program mode, be careful.
- Enter a "0" (numeral 0) and the UPS reports the present value of the battery constant.
- If this value is not correct, press "+" or "-" until the correct value is returned IAW the linked list.
- "R" save your new value and exit program mode, it should come back with "Bye"
External battery bank count
- Put the Smart Program mode (Y, 1-1)
- ">"
- "+" or "-" to change the battery count, every additional 18AH at the system voltage is considered another battery. For example my 48v 270AH battery bank is considered 15 external batteries. Depending on your model you might not be able to go past 10 external batteries.
- "R" to save and exit
Float voltage
Google for your batteries correct float voltage, make sure you use the correct temperature, most float voltages are given at 25 degrees C, most peoples houses/garages are usually less than that. Gel, flooded, and AGM batteries will all work. AGM and especially Gel batteries are sensitive to overcharging. Flooded lead acid batteries require more maintenance (watering, periodic equalization).
What you're actually changing is the UPSs battery gain, you're making the UPS think the battery voltage is higher or lower than it actually is and it adjusts its float voltage accordingly. The voltages the UPS will spit back are irrelevant, you need to have a decent digital voltmeter attached to the batteries. Just .1 volt can make the dif between getting the maximum life out of your batteries or an early battery death. When adjusting, adjust it and then let it stabilize before further adjustments. It can take a LONG time for it to stabilize depending on the size of your bank.
- Smart Program mode (Y, 1-1)
- "B"
- "+" or "-" to adjust, anything other than + or - will drop it out of battery gain adjustment mode
- "R" to save and exit
Other useful commands:
"s" (lowercase) for sensitivity to line conditions
"k" (lowercase) "+"/"-"for alarm (0=5 sec delay, T=30 sec delay, L=Low battery only, N=No alarm)
"r" for calculated runtime
"t" system temperature, this is what it uses to calculate the temperature compensation.
"m" manufacture date
Water level check should be part of your routine anyway...\
Welcome to your own powerwall....
Lead acid batteries are not big fans of semi deep discharge...and 50% is already alot for them...
I would recommedn to see whatt he floating voltage is on yours (multimeter is your friend) and check papers for batteries what they recommend and then adjust UPS accordingly:
Changing the battery constant
Use hyperterminal (or telnet, or whatever) @ 2400 baud with 8-N-1 Xon/Xoff settings, under Advanced make sure FIFO is unchecked. There can not be any network cards in the UPS for this to work.
- Put the UPS in "Smart" mode by typing Shift-Y (capital Y) it should return "SM"
- Now put it in "Program" mode by typing "1", wait 2-3 secs and type "1" again. It should return "Prog"
NOTE: It is very easy to turn your UPS into a nonresponsive brick if you type in the wrong thing while in Program mode, be careful.
- Enter a "0" (numeral 0) and the UPS reports the present value of the battery constant.
- If this value is not correct, press "+" or "-" until the correct value is returned IAW the linked list.
- "R" save your new value and exit program mode, it should come back with "Bye"
External battery bank count
- Put the Smart Program mode (Y, 1-1)
- ">"
- "+" or "-" to change the battery count, every additional 18AH at the system voltage is considered another battery. For example my 48v 270AH battery bank is considered 15 external batteries. Depending on your model you might not be able to go past 10 external batteries.
- "R" to save and exit
Float voltage
Google for your batteries correct float voltage, make sure you use the correct temperature, most float voltages are given at 25 degrees C, most peoples houses/garages are usually less than that. Gel, flooded, and AGM batteries will all work. AGM and especially Gel batteries are sensitive to overcharging. Flooded lead acid batteries require more maintenance (watering, periodic equalization).
What you're actually changing is the UPSs battery gain, you're making the UPS think the battery voltage is higher or lower than it actually is and it adjusts its float voltage accordingly. The voltages the UPS will spit back are irrelevant, you need to have a decent digital voltmeter attached to the batteries. Just .1 volt can make the dif between getting the maximum life out of your batteries or an early battery death. When adjusting, adjust it and then let it stabilize before further adjustments. It can take a LONG time for it to stabilize depending on the size of your bank.
- Smart Program mode (Y, 1-1)
- "B"
- "+" or "-" to adjust, anything other than + or - will drop it out of battery gain adjustment mode
- "R" to save and exit
Other useful commands:
"s" (lowercase) for sensitivity to line conditions
"k" (lowercase) "+"/"-"for alarm (0=5 sec delay, T=30 sec delay, L=Low battery only, N=No alarm)
"r" for calculated runtime
"t" system temperature, this is what it uses to calculate the temperature compensation.
"m" manufacture date
Water level check should be part of your routine anyway...\
Welcome to your own powerwall....
Thanks for the info...I am going to start by monitoring the float voltage..it was sitting at 13.60vdc at 15c this morning. I will log it for the next few weeks before I jump into trying to adjust it..
Nice Job! I actually have an old UPS with the wire ran out of the case to hookup 12 Deep Cycle batteries, but have not done it yet.
Bill
Good plan it was actually reasonably easy....I drilled a couple of 3/4 inch holes in the bottom of the battery holder portion and deburred them before running wire.. then #4 stranded copper from a old set of jumper cables and some connectors
. I made my own by squashing 1/2 copper plumbing pipe and soldered in the wire.. after I crimped it in a 6 inch vise.. it's all overkill butI wanted to be safe and big wire can carry the load...
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. I made my own by squashing 1/2 copper plumbing pipe and soldered in the wire.. after I crimped it in a 6 inch vise.. it's all overkill butI wanted to be safe and big wire can carry the load...
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Make sure you put grommets or wire clamps for going through the metal case. You do not want wire chaffing causing problems later on.
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