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Discussion Starter · #1 ·
Hi folks

I am setting up a small UPS system at home, what i got is a 100Ah 12V Vented Lead Acid Battery, 1000W inverter, and a 15 amp battery charger (it's just an variable transformer and a rectifier)

My question is, since i have very limited experience with battery's how should i control the charging, should i just set the charger to 12.3VDC and keep it at all time set to that ?

I am thinking of installing a PLC to control the charging, but i don't have any idea of what i should program it to do
 

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Most battery chargers already have the correct voltage setpoints, and charging cycles. Chargers go through bulk, absorb, and float. Float alone is 13.7volts for most lead acid batteries. You would benefit most from buying an off the shelf unit to charge the batteries, and just let it do its thing.
 

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Discussion Starter · #3 ·
Most battery chargers already have the correct voltage setpoints, and charging cycles. Chargers go through bulk, absorb, and float. Float alone is 13.7volts for most lead acid batteries. You would benefit most from buying an off the shelf unit to charge the batteries, and just let it do its thing.
Well this is all i got at the mean time. will keeping the charger voltage at 13.7 ruin the battery ?
 

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Well this is all i got at the mean time. will keeping the charger voltage at 13.7 ruin the battery ?
That depends, batteries vary between type & manufacturer as to the optimum float voltage. Sometimes you can get this info from the manufacturer. The other issue you need to be aware of with float or trickle charging is "mossing" which is a buildup of dendrites on the plates which happens on all LA cells during charging. On most LA batteries the dendrites get burned off every time the battery is loaded to a certain level, like a starter motor for instance. If the battery does not see enough of a load on a regular basis the dendrites will grow until they contact adjacent plates and then you will have a shorted cell.

If you want to learn more about batteries go to: http://batteryuniversity.com/


There is also a forum of guys that are waaaaay intelligent about batteries and home made stuff, they would love to see your project and offer advice. Many of them are engineers, and they make all their own stuff. It takes a day or so to join, you need to "apply" and then be accepted, well worth it though.

http://leadacidbatterydesulfation.yuku.com/
 

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Also if your battery is a deep cycle the float voltage will be lower than for a starting battery and if you put a typical starting battery float voltage on it chances are you will cook it to death.
 

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quanchai said:
Hi folks I am setting up a small UPS system at home, what i got is a 100Ah 12V Vented Lead Acid Battery, 1000W inverter, and a 15 amp battery charger (it's just an variable transformer and a rectifier) My question is, since i have very limited experience with battery's how should i control the charging, should i just set the charger to 12.3VDC and keep it at all time set to that ? I am thinking of installing a PLC to control the charging, but i don't have any idea of what i should program it to do
What kind of battery? It makes a difference. A deep cycle like a golf cart battery will fail if you leave it on a trickle charger all the time. They do better if you charge them, let them sit and recharge when they dropped 20%. If it's a UPS battery, then set the charger and forget it. That's what their made for. But the charger needs to be correct for it. Battery manufactures are you go to for info on that.
 

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Hi folks

I am setting up a small UPS system at home, what i got is a 100Ah 12V Vented Lead Acid Battery, 1000W inverter, and a 15 amp battery charger (it's just an variable transformer and a rectifier)

My question is, since i have very limited experience with battery's how should i control the charging, should i just set the charger to 12.3VDC and keep it at all time set to that ?

I am thinking of installing a PLC to control the charging, but i don't have any idea of what i should program it to do
What is the application for this UPS?
Is it just for a back up or are you going to use it for a certain time each day?
 
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