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electrical:12v:drop-in_lifepo4 [2025/11/22 00:15] frater_secessus [BMS features and specs] added caveats of active balancing |
electrical:12v:drop-in_lifepo4 [2026/01/31 17:42] (current) frater_secessus [Brands and specs] |
| **Capacitive balancing** wastes less power since most of the excess is transferred to the low cell[s]. There are efficiency losses involved (~50%((https://www.ti.com/download/trng/docs/seminar/Topic%202%20-%20Battery%20Cell%20Balancing%20-%20What%20to%20Balance%20and%20How.pdf))) but it's far less than the 100% loss of passive balancing. The main drawbak of capacitive balancers is the current spec (like 5A) only occur at huge deltas; the rest of the time the balancing current is much lower. | **Capacitive balancing** wastes less power since most of the excess is transferred to the low cell[s]. There are efficiency losses involved (~50%((https://www.ti.com/download/trng/docs/seminar/Topic%202%20-%20Battery%20Cell%20Balancing%20-%20What%20to%20Balance%20and%20How.pdf))) but it's far less than the 100% loss of passive balancing. The main drawbak of capacitive balancers is the current spec (like 5A) only occur at huge deltas; the rest of the time the balancing current is much lower. |
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| Heads up: because active balancers are just shuffling voltage between cells they can theoretically overdischarge the cells. To avoid this: | Heads up: because active balancers are just shuffling voltage between cells they can overdischarge the cells if left alone without adult supervision. To avoid this: |
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| * use [[electrical:12v:lvd|an LVD]] to cut the circuit to the balancer's single NEG lead when pack voltage is <13.0v or some other value of your choosing. Or, | * use [[electrical:12v:lvd|an LVD]] to cut the circuit to the balancer's single NEG lead when pack voltage is <13.0v or some other value of your choosing. Or, |
| The most popular drop-ins at various price points appear to be: | The most popular drop-ins at various price points appear to be: |
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| * premium - [[https://amzn.to/3LV85DI|Battle Born]], Lithionics | * premium - [[https://amzn.to/3LV85DI|Battle Born]]((but see Will Prowse's [[https://www.youtube.com/watch?v=DUtbnbLpvFk|recent series on failures]])), Lithionics |
| * midrange - [[https://amzn.to/3YxGPTh|SOK]], Epoch. And there are companies like SunFunKits that will [[https://www.sunfunkits.com/category/3/pre-built-batteries|build LFP batteries with the customer's choices of options]]. | * midrange - [[https://amzn.to/3YxGPTh|SOK]], Epoch. And there are companies like SunFunKits that will [[https://www.sunfunkits.com/category/3/pre-built-batteries|build LFP batteries with the customer's choices of options]]. |
| * inexpensive - [[https://amzn.to/4cfU5Pm|Li Time]] (was Ampere Time), [[https://amzn.to/4dwItZr|Weize]], [[https://amzn.to/4fwJhiQ|Power Queen]], [[https://amzn.to/4cgSKIj|Roypow / Power Urus]], etc | * inexpensive - [[https://amzn.to/4cfU5Pm|Li Time]] (was Ampere Time), [[https://amzn.to/4dwItZr|Weize]], [[https://amzn.to/4fwJhiQ|Power Queen]], [[https://amzn.to/4cgSKIj|Roypow / Power Urus]], etc |