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sporkman427 OP t1_j89vabs wrote

Reply to comment by brock_lee in diy LifePo4 power station by sporkman427

I understand it wouldn't power it for long, but I never use it all day or I'd bring the bigger gas generator with me. Maybe what I was really asking was if one battery can handle the surge of a table saw (3k or 4k surge watts) or use 2 batteries to spread the load out. I'll keep in mind the cheap charge controller.

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Jabberwocky918 t1_j8akz9k wrote

You should double up the LiFePo4 batteries. They are usually rated to 1C discharge rates or 1 times its capacity. In this case, you're limited to 100 amps, or 1,200 watts, continuously.

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Diligent_Nature t1_j8ao3go wrote

> if one battery can handle the surge of a table saw

That depends on how much current the battery can provide. The Ah rating is not a measure of power or energy. Ah times volts is energy in watt-hours. You need a high enough Continuous Discharge Rating (CDR) for the peak load. 15A @120VAC is the same power as 150A at 12VDC (ignoring conversion losses). The Ah rating can be used to estimate run time, but the Ah rating is not specified at maximum discharge rate. A 2000mAh cell can deliver 2A for an hour, but if you draw 20 A from it, the Ah rating will go down. It won't run a 20A load for 0.1 hour.

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sporkman427 OP t1_j8avphj wrote

I like the one guy who commented and made a cart for his batteries in another thread. And the more I think about it, having 2 would be better overall for lots of reasons for wear and tear and extended time. Maybe 30 minutes might not be enough but an hour would. Now I'm if a single bank charger is ok for 2 batteries in parallel or get a 2 bank charger.

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Diligent_Nature t1_j8awr1c wrote

I would charge them together. Two chargers mean you have to disconnect/charge/reconnect the 2 packs each time. And the 2 packs must be at the same state of charge when paralleled.

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sporkman427 OP t1_j8aydev wrote

Didn't know I could do that. I'm pretty rubbed in with residential electric in houses since I've remodeled homes for 20 years. But this dc/battery stuff throws me off. Can I leave the inverter hooked to along with the charger or should I buy 1 or 2 disconnects?

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Diligent_Nature t1_j8b0n8k wrote

As long as the inverter has an ON/OFF switch, you can leave it connected. Make sure you fuse the battery output.

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