BMS amp rating

S

starbits

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I am building a 14s28p battery (3.7v 4.4ah 16.28wh cells). It will be connected to a Reliable 3000 watt inverter. So 3000 watts at 120v is 25 amps and 3000 watts at 48v is 62.5 amps and I saw one comment that the Daly BMS should be derated 50% for real world applications. Charging source will be solar panels. It is being built to be portable not for a specific item so the power draw could be anywhere from a refrigerator to microwave to small AC. I am seeing BMS amp ratings from 25 to 250 and I have no idea what I should be looking at and why.
 
3000w at 48v is more like ;80-90A with losses. The n dont forget surge rating. Look at the inverters manual what fusing is needed.

14s28p is to small IF you use laptop cells. Should be more like 14s100p or even 200p. What cell type? IF they are 18650 then you have fake cells because 4.4ah doesnt exist.

The bms is protection so dont skimp out on that.
 
Oki. That can work then. :)
 
So if 80-90 with losses and a surge rating double to 6k you would need 160-180 amp rating?
 
Depends on the inverter. What does it say? Note that a fuse can take alot higher load short burst of times. So you should not double the fuse but perhaps that inverter should be fused with 100A?

Note that every point need to be stronger than 100A then including the battery bank.
 
Unfortunately - a Reliable 3000 is cheap/high-frequency andwill not tolerate surge. I burned up a 3000 Reliable trying to start a 12,000BTU AC unit (120v @ 12a moninal). So I wouldn't worry about trying to accommodate2x or 3x surge for this inverter.Based on @Daromer's advice - I'd shoot for 100-150a rangeBMS.
 
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