Lithium-ion multiple batteries on parallel - same challenge as Lead Acid or not?
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hitting so many. This will be a very low production day, I had better read the inverters before they
get shut down.
What not many realize, the transistor had advantages over tubes, but it was the integrated circuit
(1957) that revolutionized electronics. The first ICs at work half a century ago had 4 transistors,
the one I did a couple decades later had 175,000, and they are at some power of billions last I heard.
Tubes are still around, there is a 1940 style magnetron in every microwave oven. Bruce RoeComment
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MSEE, PEComment
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Been away a few days - 2 pages of off-topic - Can we get back on track?
"Lithium-ion multiple batteries on parallel - same challenge as Lead Acid or not?
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Norwegian off grid cabin owner
Panels facing south
- Kyocera panels 135W
- Tristar 60A MPPT
- Victron 3000w/12V / 120AComment
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Not it is not the same challenge because they are done differently. Pb batteries are paralleled at the String Level and self equalize given enough time when needed, and Li is paralleled at the Cell level and require either Vampire Boards (passive autonomous) used at the DIY level which is pretty much guaranteed to kill your batteries, or Active integrated with the charger.
Rather than go through every method Davide Andrea a very good friend of mine wrote the book on BMS. He has one of the best websites on the internet. Considered working for him several years ago, but had no interest in living in Boulder. Check out his site and you can learn everything there is to know about lithium batteries and BMS. Check out the tutorials, white papers and why you parallel at the Cell level and not on the String level. You will also find just about every BMS, Lithium Ion Battery, Battery Pack, and Integrated Circuit made for Li batteries. It will take you a long time to go through it all, but when done you will have a really good idea of what is going on.
Again my apologies. Davide also makes one good BMS from his own Integrated Circuit design made just for his company BMS product. Another good one for DIY is Orion. Use one of the Selector tools to find a BMS that will work for you. Just remember one thing. A BMS cannot balance an out of Balance Lithium Battery. They can only keep a Balanced pack Balanced with very minor tiny corrections.Last edited by Sunking; 11-26-2018, 09:10 PM.MSEE, PEComment
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Not it is not the same challenge because they are done differently. Pb batteries are paralleled at the String Level and self equalize given enough time when needed, and Li is paralleled at the Cell level and require either Vampire Boards (passive autonomous) used at the DIY level which is pretty much guaranteed to kill your batteries, or Active integrated with the charger.
Rather than go through every method Davide Andrea a very good friend of mine wrote the book on BMS. He has one of the best websites on the internet.
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Norwegian off grid cabin owner
Panels facing south
- Kyocera panels 135W
- Tristar 60A MPPT
- Victron 3000w/12V / 120AComment
-
Davide's written material on the disadvantages of paralleling strings is mostly misinformed or misleading, although its overall suggestion is true: it is often better to parallel first, then place in serial.
But there are times when it is better (or even necessary) to place multiple serial strings in parallel, and it is perfectly doable. It usually costs more, but it comes with advantages.
Please be careful heeding Sunking's regurgitated advice in this area. He does not have hands-on experience with the topology. And be skeptical of any material put out by BMS-producing companies. They are often great engineers, but they have to feed their families, and in my experience they are prone to overstating the concerns in their marketing material.
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MSEE, PEComment
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