alcatraz Posted June 7, 2022 Share Posted June 7, 2022 Jikong 极空 1 Quote Link to comment Share on other sites More sharing options...
alcatraz Posted June 7, 2022 Share Posted June 7, 2022 It's also got 0.6A (and versions up to 2A) of balancing current, that doesn't only bleed but distributes charge. If you have only one weak group that will be topped up instead of bleeding the rest. Also you coule balance REALLY shitty packs very fast. Quote Link to comment Share on other sites More sharing options...
power pan Posted June 7, 2022 Share Posted June 7, 2022 (edited) On 6/5/2022 at 6:31 AM, alcatraz said: An intelligent bms is only 50usd retail in China. Wholesale price? Imagine that it's too expensive for the manufacturers. It's got bluetooth and it's configurable to balance at any voltage, monitors internal resistance and voltages of all groups. There are two thermal probes. You can connect a separate display to it where it shows you the details while riding. yes, 50USD for bt BMS boards but it could only provide poor balancing current like less than 1A... it's nothing... the price not wholesale price but retail price. bom is around 20USD. @alcatraz where were you original from ? but really I don't know why they don't make higher balancing current... it's easy and the output current is easy to upgrade... Edited June 7, 2022 by power pan put more detail Quote Link to comment Share on other sites More sharing options...
power pan Posted June 7, 2022 Share Posted June 7, 2022 On 6/5/2022 at 1:34 AM, OneLeg said: I have created a new thread on the ninebot forum where you can post the photos. if you look in the box you reply in on the bottom left there is a drag photos or attach files link. I actually think that we should be asking manufacturers to build battery packs using intellingent BMS where we can get per cell voltage and also be able to trigger balancing at any voltage. I think we should tell vendors to shove their suspension and BS and tell them we are going to boycott all new wheel launches which dont' have a BMS that is going to allow us to extend the life of the pack / wheel. I could only see "insert image from URL" on the bottom right but nothing on the bottom left. or I don't have the privilege ? 1 Quote Link to comment Share on other sites More sharing options...
alcatraz Posted June 7, 2022 Share Posted June 7, 2022 7 hours ago, power pan said: yes, 50USD for bt BMS boards but it could only provide poor balancing current like less than 1A... it's nothing... the price not wholesale price but retail price. bom is around 20USD. @alcatraz where were you original from ? but really I don't know why they don't make higher balancing current... it's easy and the output current is easy to upgrade... 600mA is very good for a bms. For an external balancer it's useless. You're right. It's going to take a really damaged pack or mixed cell pack to overpower 600mA over a long period. For huge packs you can get the 2A ones too. The stock bms' in wheels I'm quite sure have at most 100mA, some much less. They only work with extremely well matched cells. I'm swedish but I live in China for many years. 1 Quote Link to comment Share on other sites More sharing options...
power pan Posted June 8, 2022 Share Posted June 8, 2022 (edited) 14 hours ago, alcatraz said: 600mA is very good for a bms. For an external balancer it's useless. You're right. It's going to take a really damaged pack or mixed cell pack to overpower 600mA over a long period. For huge packs you can get the 2A ones too. The stock bms' in wheels I'm quite sure have at most 100mA, some much less. They only work with extremely well matched cells. I'm swedish but I live in China for many years. heat problem is the major problem in balancing. I'm trying to reduce the heat @ high balance current, but with many cells, it's a little bit hard, but it's doable, and already figured a way out.... I happened to know a Swedish in SZ who's in e-sports industries. now he's in HK setting up his team(he left to HK early 2020). Edited June 8, 2022 by power pan Quote Link to comment Share on other sites More sharing options...
alcatraz Posted June 8, 2022 Share Posted June 8, 2022 1 hour ago, power pan said: heat problem is the major problem in balancing. I'm trying to reduce the heat @ high balance current, but with many cells, it's a little bit hard, but it's doable, and already figured a way out.... I happened to know a Swedish in SZ who's in e-sports industries. now he's in HK setting up his team(he left to HK early 2020). Bleed resistors produce heat. If it's shuffling charge around highest > lowest (capacitor based), then the bms shouldn't get very warm. (I think) Quote Link to comment Share on other sites More sharing options...
power pan Posted June 8, 2022 Share Posted June 8, 2022 2 hours ago, alcatraz said: Bleed resistors produce heat. If it's shuffling charge around highest > lowest (capacitor based), then the bms shouldn't get very warm. (I think) it affects the life of the battery pack, that's the major point. 1 Quote Link to comment Share on other sites More sharing options...
alcatraz Posted June 8, 2022 Share Posted June 8, 2022 The balancing currents are small in comparison to charge/discharge currents. So the cells are not stressed when balancing. Cells that are discharging faster (more deteriorated) are going to experience a bit more cycling because they need to be balanced (with capacitor based balancing). With bleed resistors it's the opposite. All the less deteriorated cells are cycled more than the most deteriorated cell. It's the only quality, despite being the cheapest. 1 Quote Link to comment Share on other sites More sharing options...
OneLeg Posted June 11, 2022 Author Share Posted June 11, 2022 On 6/7/2022 at 12:17 PM, power pan said: yes, 50USD for bt BMS boards but it could only provide poor balancing current like less than 1A... it's nothing... the price not wholesale price but retail price. bom is around 20USD. @alcatraz where were you original from ? but really I don't know why they don't make higher balancing current... it's easy and the output current is easy to upgrade... The issue is cost and size. Capacitors are big and expensive. Balancing boards are already expensive compared to BMS and also if you want the BMS onboard if it can do many A it has to be big..... On 6/8/2022 at 9:53 AM, power pan said: heat problem is the major problem in balancing. I'm trying to reduce the heat @ high balance current, but with many cells, it's a little bit hard, but it's doable, and already figured a way out.... I happened to know a Swedish in SZ who's in e-sports industries. now he's in HK setting up his team(he left to HK early 2020). DM me an introduce me to him... Quote Link to comment Share on other sites More sharing options...
OneLeg Posted June 11, 2022 Author Share Posted June 11, 2022 On 6/8/2022 at 2:26 PM, alcatraz said: The balancing currents are small in comparison to charge/discharge currents. So the cells are not stressed when balancing. Cells that are discharging faster (more deteriorated) are going to experience a bit more cycling because they need to be balanced (with capacitor based balancing). With bleed resistors it's the opposite. All the less deteriorated cells are cycled more than the most deteriorated cell. It's the only quality, despite being the cheapest. I am not sure how they work but from what I can see on those boards that are carpet of capacitors they are probably not very intelligent. I think a balancer could be designed to make the least number of switches of connecting cell to cell possible and involve the least number of the cells in the balancing, and use the least possible number of amp movements. I am sure that would cost a lot. Maybe a single capacitor and time switching. Quote Link to comment Share on other sites More sharing options...
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