Popular Post Chronic Posted February 29, 2020 Popular Post Share Posted February 29, 2020 (edited) I ran a simple test drive. I can feel the power of the motor. The Msp will certainly give you pleasure riding I'll be working on a battery expansion soon (24S1P) Expect an increase in battery capacity (About 2178Wh(25Ah)) I have checked the BMS loadspace and arrangement I think up to 24S2P is possible. but it would make the work process very difficult I will try the easy direction first. I'll share some of the battery addition expansion work reviews later see you later guys wish me luck Edited February 29, 2020 by Chronic 16 Quote Link to comment Share on other sites More sharing options...
mrelwood Posted March 5, 2020 Share Posted March 5, 2020 Be sure to take account the cell connecting strips, cabling and wrapping. The way you have them right now won’t fit when the pack is complete. I installed an extra pack on my MSX, and the thickness really does build up fast if you want to make the pack resilient and waterproof. 2 Quote Link to comment Share on other sites More sharing options...
alcatraz Posted March 8, 2020 Share Posted March 8, 2020 Will you buy a gotway 24s bms for the extra pack? Does the original pack use 18650 or 21700 cells? Quote Link to comment Share on other sites More sharing options...
Popular Post alcatraz Posted March 8, 2020 Popular Post Share Posted March 8, 2020 This is what the chinese do to their euc's when they want to have long range and make them near indestructable. This ks-18s has a 3400Wh pack. Haven't seen a gotway yet though. 12 Quote Link to comment Share on other sites More sharing options...
Meserias Posted March 8, 2020 Share Posted March 8, 2020 this is insane... but also very unique Quote Link to comment Share on other sites More sharing options...
alcatraz Posted March 11, 2020 Share Posted March 11, 2020 In china it's not unique. I've seen dozens of these on the market. They look basically the same and are 99% made from a KS-18S. They were 3000+Wh quite a few years ago. I believe today they could be made over 4000Wh. People take them on long travels out to nowhere. Every once in a while you see pictures of nomads on these. 2 Quote Link to comment Share on other sites More sharing options...
Chronic Posted March 23, 2020 Author Share Posted March 23, 2020 (edited) On 3/6/2020 at 4:32 AM, mrelwood said: Be sure to take account the cell connecting strips, cabling and wrapping. The way you have them right now won’t fit when the pack is complete. I installed an extra pack on my MSX, and the thickness really does build up fast if you want to make the pack resilient and waterproof. Thank you for your advice. I'm almost at the end of the work Edited March 23, 2020 by Chronic 3 Quote Link to comment Share on other sites More sharing options...
Chronic Posted March 23, 2020 Author Share Posted March 23, 2020 (edited) On 3/8/2020 at 3:27 PM, alcatraz said: Will you buy a gotway 24s bms for the extra pack? Does the original pack use 18650 or 21700 cells? The battery cell was the same as the original LG M50T 21700 5000mAh, BMS 24S 50A Edited March 23, 2020 by Chronic Quote Link to comment Share on other sites More sharing options...
someguy152 Posted March 24, 2020 Share Posted March 24, 2020 On 3/8/2020 at 1:37 AM, alcatraz said: this is amazing Quote Link to comment Share on other sites More sharing options...
Han Vo Posted March 29, 2020 Share Posted March 29, 2020 On 3/22/2020 at 5:19 PM, Chronic said: Thank you for your advice. I'm almost at the end of the work How much andis it hard to install Quote Link to comment Share on other sites More sharing options...
alcatraz Posted April 8, 2020 Share Posted April 8, 2020 Wow. 4 bms in one wheel. If the original packs weren't too nice to break apart you could piggyback the additional packs off of the bms' in the bigger packs. Are they also communicating with the control board these additional bms? Quote Link to comment Share on other sites More sharing options...
Planemo Posted April 8, 2020 Share Posted April 8, 2020 On 3/23/2020 at 12:19 AM, Chronic said: So it looks like you have made 3 complete kits? So 2 other lucky people are getting battery upgrades for their MSP too? 2 Quote Link to comment Share on other sites More sharing options...
Popular Post Chronic Posted April 9, 2020 Author Popular Post Share Posted April 9, 2020 (edited) 17 hours ago, Planemo said: So it looks like you have made 3 complete kits? So 2 other lucky people are getting battery upgrades for their MSP too? Yes, that's right. The battery works perfectly, and we're riding test drive Edited April 9, 2020 by Chronic 6 Quote Link to comment Share on other sites More sharing options...
Planemo Posted April 9, 2020 Share Posted April 9, 2020 That's awesome! The LED charge indicators for each string are a really nice touch as well. Do you mind sharing where you purchased the BMS'? Cheers Quote Link to comment Share on other sites More sharing options...
Chronic Posted April 14, 2020 Author Share Posted April 14, 2020 (edited) On 4/9/2020 at 4:55 PM, Planemo said: That's awesome! The LED charge indicators for each string are a really nice touch as well. Do you mind sharing where you purchased the BMS'? Cheers Of course ₩ 32,410 11％ Off | 24S 86V 72V 50A 40A 30A 18650 lithium battery protection board BMS Li-ion lifepo4 20S 22S 16S 48V 60V W LED balance indicatorhttps://a.aliexpress.com/_dSHFnZE Edited April 14, 2020 by Chronic Quote Link to comment Share on other sites More sharing options...
alcatraz Posted April 14, 2020 Share Posted April 14, 2020 (edited) 20-30mA balancing current is low. Also the bms doesn't communicate with the control board to stop charging if a cell group goes over the maximum voltage. It's good if you check voltages after charging once every few months. For others considering this mod you can either get a gotway bms (about the same price ~30usd last I checked) or you can open an existing pack, solder balance wires and piggy back your added pack onto the original bms. Then you get charge protection and probably a little more than 20-30mA balancing current. Edited April 14, 2020 by alcatraz Quote Link to comment Share on other sites More sharing options...
Planemo Posted April 14, 2020 Share Posted April 14, 2020 Does the Gotway BMS communicate with the control board then? I thought the charge circuit was totally independent of the mother board. As you say it does make sense to just use a genuine GW bms as they are proven although the last time I looked they were about £80. Not a deal breaker at all though. I just wondered if the bms used by the OP offered anything over and above the GW bms. The charge lights looked handy for the occasional check but I did have concerns over the max 50A rating. Quote Link to comment Share on other sites More sharing options...
Chriull Posted April 14, 2020 Share Posted April 14, 2020 3 minutes ago, Planemo said: Does the Gotway BMS communicate with the control board then? I thought the charge circuit was totally independent of the mother board. The cell overvoltage protection at the charge side gets voided by the paralleling at the discharge side. I'd guess the "syncronisation lines" used by GW/KS "just" syncronize the charge input protections of all BMS - if one cuts the input the others follow. So there is no real reason to involve the motherboard - maybe just to connect the syncronisation wires? Quote Link to comment Share on other sites More sharing options...
alcatraz Posted April 14, 2020 Share Posted April 14, 2020 How can the BMS cut the charge input? Gotway wheels charge through the output wires. There must be a charge relay somewhere that can be controlled with the control wires. Then there's overheat protection to trigger some kind of tiltback. There must also be overcharge protection that triggers tiltback when trying to descend with a full battery. I guess that last one can be done by the control board but if individual groups go over 4.2v without the pack going over 84V (or 100.6V) then the bms must kick in with tiltback and beeps reporting a battery error. Quote Link to comment Share on other sites More sharing options...
Chriull Posted April 14, 2020 Share Posted April 14, 2020 2 hours ago, alcatraz said: How can the BMS cut the charge input? Gotway wheels charge through the output wires. If so, then they changed this with the newer models (since i've seen GW BMS). From ecodrifts teardown of the nikola they still have the charge input and the discharge output seperate. Also the gw monster bms he sells has definitely different input and output. 2 hours ago, alcatraz said: There must be a charge relay somewhere that can be controlled with the control wires. The "typical" BMS i know has the charge input, after this the input protection circuitry (for GW a MOSFET which cuts the connection in case of cell overvoltage). 2 hours ago, alcatraz said: Then there's overheat protection to trigger some kind of tiltback. That's done solely by the mainboard. 2 hours ago, alcatraz said: There must also be overcharge protection that triggers tiltback when trying to descend with a full battery. Same here. The mainboard measures the battery voltage and triggers the tiltback if too high. 2 hours ago, alcatraz said: I guess that last one can be done by the control board but if individual groups go over 4.2v without the pack going over 84V (or 100.6V) then the bms must kick in with tiltback and beeps reporting a battery error. The control board measures the overall pack battery and issues an tiltback in case of overvoltage. Cell voltage (4.2V) is only checked by the BMS and not reported to the control board. It just cuts charging... No intervention while driving... 2 Quote Link to comment Share on other sites More sharing options...
alcatraz Posted April 14, 2020 Share Posted April 14, 2020 (edited) If the bms can't trigger a tiltback we're in trouble. Conventional bms have charge terminals. Euc bms don't. How do they cut charging? It must be done by communicating to a charge circuit somewhere else. I was talking about battery temperature. On inmotion there are temp sensors inside the middle of the battery pack. If a cell shorts and causes 150 degrees C in the pack it's probably a good idea to stop riding before other people are waving to you your euc is smoking. I guess it's also possible to turn off charging if the battery temp goes over a certain level. With 1.5A chargers no problem but I saw some try to charge with 10A. The mod in this thread has likely no overcharge protection. Lets say corrosion kills a cell group. He'd charge the other cells to 4.4v and ride it oblivious, repeatedly until there's a fire. That's why he should open it up every few months to see it's all level. Or use a gotway bms and hook it up to the communication harness. If it were for himself alone it's fine. He's aware there is some maintenance and he can clearly perform it. If he makes packs for someone else then he ought to inform them that it's not zero maintenance. My packs have several flaws, and it's fine as long as you're aware of them and take some measures. I didn't mean to kill the enthusiasm. Sorry if I did. Edited April 15, 2020 by alcatraz Quote Link to comment Share on other sites More sharing options...
Arbolest Posted April 15, 2020 Share Posted April 15, 2020 Correct me if I'm misunderstanding something, but I'm having trouble following the logic in your last post, @alcatraz. 1 hour ago, alcatraz said: If the bms can't trigger a tiltback we're in trouble. Why is this? As far as I know this has never been the case for any wheel. It's ALWAYS the control board that triggers a tiltback. Can you give an example of any wheel where the BMS triggers a tiltback? 59 minutes ago, alcatraz said: Conventional bms have charge terminals. Euc bms don't. ... Not sure what you're talking about here. EUC bms (at least the Gotway ones) ABSOLUTELY have specific charging terminals that are electrically distinct from the main power outputs. 1 hour ago, alcatraz said: How do they cut charging? It must be done by communicating to a charge circuit somewhere else. I don't believe so. I'm pretty sure that the BMS will continue to charge the entire pack even as some cell groups go into their balancing mode. The balancing mode is very simple and activates at a specific voltage threshold. It just allows current to leak (discharge) at a low rate and prevents the cell group from over-charging and reaching a voltage that is dangerously high. This effectively "cuts charging". There may or may not be additional pack-level behavior when all cell groups are actively in this mode, but as far as I am aware that is the extent of it. There is no "charge circuit" anywhere else. The BMSs in Gotway wheels are only connected to each other. There is no communication with either the main control board of the wheel, nor with the charger. 1 hour ago, alcatraz said: .... Lets say corrosion kills a cells group. He'd charge the other cells to 4.4v and ride it oblivious, repeatedly until there's a fire. ... Even given the total maximum voltage of the charger, a battery pack with a damaged/nonfunctional cell group would never reach the total voltage of the charger. The other working cell groups would reach their balancing mode voltage thresholds and would simply stop charging. 3 Quote Link to comment Share on other sites More sharing options...
mrelwood Posted April 15, 2020 Share Posted April 15, 2020 1 hour ago, alcatraz said: If the bms can't trigger a tiltback we're in trouble. Excluding the Z10, it can’t. Tilt-back is purely a controller software feature, and for it to be able to tiltback on individual cell group behaviour, there should be a communication channel between the bms and the main board. There isn’t, except on the Z10. @Arbolest beat me to the other points of my reply... 2 Quote Link to comment Share on other sites More sharing options...
alcatraz Posted April 15, 2020 Share Posted April 15, 2020 (edited) If they have charge terminals then thats ok. I don't see any on planemo's mod though so that pack isn't protected. What my followup question is then, when a wheel has multiple packs connected in parallell where one has reached it's balancing voltage below the end voltage of the other packs (imagine it is unbalanced or damaged) and it cuts charging. It will then continue to charge from the parallell connection to the other packs through the output wires regardless if it has cut it's own charge terminal or not. That's what leads me to think there must be a charge circuit that cuts charging to all the packs. Edited April 15, 2020 by alcatraz Quote Link to comment Share on other sites More sharing options...
alcatraz Posted April 15, 2020 Share Posted April 15, 2020 11 minutes ago, mrelwood said: Excluding the Z10, it can’t. Tilt-back is purely a controller software feature, and for it to be able to tiltback on individual cell group behaviour, there should be a communication channel between the bms and the main board. There isn’t, except on the Z10. @Arbolest beat me to the other points of my reply... The bms should signal battery malfunction to the control board and the control board turns on the fans and stops the wheel. Quote Link to comment Share on other sites More sharing options...
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