sunny Posted May 12, 2015 Author Share Posted May 12, 2015 If you want to modify wheels to sell them then I would get someone on board who knows what they're doing in terms of electronics. Link to comment Share on other sites More sharing options...
CloudMG Posted May 12, 2015 Share Posted May 12, 2015 its funy i actualy have an electricionner whaterver u call it diploma from school but i forgot almost everything exept the wiring part more or less, and the world evolved and stuff so, question dose it mater how many cells the battery has ? becouse i saw on hobyking the zippy batterys and i was douthing about the mather cuz there cheaper whit less cells Link to comment Share on other sites More sharing options...
Gimlet Posted May 12, 2015 Share Posted May 12, 2015 its funy i actualy have an electricionner whaterver u call it diploma from school but i forgot almost everything exept the wiring part more or less, and the world evolved and stuff so, question dose it mater how many cells the battery has ? becouse i saw on hobyking the zippy batterys and i was douthing about the mather cuz there cheaper whit less cells The number of batteries in each pack is critical to the voltage output. You can add additional packs and wire them in parallel which will give higher power delivery capabilities but only if the control board and all other components/connections can deal with the higher amps. Link to comment Share on other sites More sharing options...
Azzie Posted May 27, 2015 Share Posted May 27, 2015 Hello RockWheel fans,I apologize in advance for my bad English.I had one question for a little modding Rockwheel GR12 unocycle. What do u think ? Is possible to replace both of current battery packs which contains (14x ? )Pansonic NCR18650PF [ http://eu.nkon.nl/rechargeable/18650-size/panasonic-ncr18650pf-3-7v-2900mah.html ] with a new battery packs which contains (14x ) Pansonic NCR18650B [ http://eu.nkon.nl/rechargeable/18650-size/panasonic-ncr18650b.html ] ? In this case a nominal Voltage will be a little increased, but a rly little bit. Might it work with this alteration ? Or is this modification too risky for inner segaway systems ?Thank you very much for your response and your opinion.*Azzie* Link to comment Share on other sites More sharing options...
MetricUSA Posted May 27, 2015 Share Posted May 27, 2015 Oooh, buy 540 and get good discount.... For only $2537.07! Link to comment Share on other sites More sharing options...
Chriull Posted May 27, 2015 Share Posted May 27, 2015 .... What do u think ? Is possible to replace both of current battery packs which contains (14x ? )Pansonic NCR18650PF [ http://eu.nkon.nl/rechargeable/18650-size/panasonic-ncr18650pf-3-7v-2900mah.html ] with a new battery packs which contains (14x ) Pansonic NCR18650B [ http://eu.nkon.nl/rechargeable/18650-size/panasonic-ncr18650b.html ] ? In this case a nominal Voltage will be a little increased, but a rly little bit. Might it work with this alteration ? Or is this modification too risky for inner segaway systems ?... According to your links the PF is a "High drain LiNiMnCoO2 battery - Maximum 10A constant discharge current". Type B misses that note. According to another data sheet, B has an inner resistance of 66 milli Ohm instead of only 22 milli Ohm of the PF.So this does not really sound recommendable. 3 times the inner resistance means three times the power "burned" inside the battery -> could maybee lead to a temperature problem. The other question is, if type B can deliver the necessary current for the wheel to operate reasonable. I did not find a data sheet of type B with the maximum (constant) discharge current. Discharging a Li Ion Akku with currents above the specification however leads to loss of capacity. Link to comment Share on other sites More sharing options...
OleTC Posted May 28, 2015 Share Posted May 28, 2015 According to your links the PF is a "High drain LiNiMnCoO2 battery - Maximum 10A constant discharge current". Type B misses that note. According to another data sheet, B has an inner resistance of 66 milli Ohm instead of only 22 milli Ohm of the PF.So this does not really sound recommendable. 3 times the inner resistance means three times the power "burned" inside the battery -> could maybee lead to a temperature problem. The other question is, if type B can deliver the necessary current for the wheel to operate reasonable. I did not find a data sheet of type B with the maximum (constant) discharge current. Discharging a Li Ion Akku with currents above the specification however leads to loss of capacity. As for the inner resistance, a value that is 3 times higher sounds bad but the actual problem can't be really noticable.Consider a resistance of 66 mill Ohm = 0,00066 Ohm. If the engine draws 5 Ampere, the effect that is lost in the cell is 0,066 x 5 x 5 = 1,65 Watt. Don't know how much this will heat the cell?As for the max. discharge current, I have seen it quoted as 6500 mA. That could be an issue and 2 or 3 parallel packs could be needed to stay out of problems for the more extreme Wheels. Link to comment Share on other sites More sharing options...
esaj Posted May 28, 2015 Share Posted May 28, 2015 66 milliohms is actually 0.066 ohms (milli = 1/1000th). Maybe you're confusing it with micro ohms (µOhm / µΩ)? Refer to http://en.wikipedia.org/wiki/International_System_of_Units#Prefixes Link to comment Share on other sites More sharing options...
OleTC Posted May 28, 2015 Share Posted May 28, 2015 66 milliohms is actually 0.066 ohms (milli = 1/1000th). Maybe you're confusing it with micro ohms (µOhm / µΩ)? Refer to http://en.wikipedia.org/wiki/International_System_of_Units#Prefixes You're right, Esaj. I'm home with the flu and my head is feeling inflated like a balloon. Will rewrite the post. Link to comment Share on other sites More sharing options...
esaj Posted May 28, 2015 Share Posted May 28, 2015 You're right, Esaj. I'm home with the flu and my head is feeling inflated like a balloon. Will rewrite the post.Yeah, no problem... I don't know that much about electronics, but thought that an error by a multiple of 100 could be somewhat meaningful Also, isn't the internal resistance the sum of all cells in series, if 66mOhms is the internal resistance of a single cell? Link to comment Share on other sites More sharing options...
Chriull Posted May 28, 2015 Share Posted May 28, 2015 As for the inner resistance, a value that is 3 times higher sounds bad but the actual problem can't be really noticable.Consider a resistance of 66 mill Ohm = 0,00066 Ohm. If the engine draws 5 Ampere, the effect that is lost in the cell is 0,066 x 5 x 5 = 1,65 Watt. Don't know how much this will heat the cell?As for the max. discharge current, I have seen it quoted as 6500 mA. That could be an issue and 2 or 3 parallel packs could be needed to stay out of problems for the more extreme Wheels.The Rockwheel GR12 has a motor power of 500W. With an efficiency factor of 1 (i do not have any idea how much this could be in reality ) the battery pack would need to deliver 9A. So at least 2 packs are needed in parallel for the current at full load.The open question is, if and how the battery pack can handle peak currents - and in which magnitude they occur while accerlerating/startup/etc. Link to comment Share on other sites More sharing options...
OleTC Posted May 28, 2015 Share Posted May 28, 2015 Yeah, no problem... I don't know that much about electronics, but thought that an error by a multiple of 100 could be somewhat meaningful Also, isn't the internal resistance the sum of all cells in series, if 66mOhms is the internal resistance of a single cellYes it is. So each cell would take a heating of 1,65 W and with 16 cells in a pack, it would sum up to 26,4 W, distributed over all cells. I'm not sure this is a big problem. Link to comment Share on other sites More sharing options...
Azzie Posted June 4, 2015 Share Posted June 4, 2015 So,Does anyone have an idea, how to build battery repack with longer range ?Is it already possible or can I use only Pansonic NCR18650PF ? Link to comment Share on other sites More sharing options...
JLG Paris Posted June 5, 2015 Share Posted June 5, 2015 So,Does anyone have an idea, how to build battery repack with longer range ?Is it already possible or can I use only Pansonic NCR18650PF ? Hello,I'm new in the Unicycle world. Just to introduce myself : Just got one fiew weeks ago, With a fake battery capacity. (At this time they are no affordable 5000mAh 18650, this does not exist) you can find it in some places like the 13500mAh of ClousMG but it's fake. It's like a 1 litre bottle of water, you can write 2 litres but it won't have more than one litre. Azzie do you know how much power your unycicle need ?What are the good Rockwheel battery made of ? And what is the brand of your battery cells right now ?Are you going to keep the electronic board of your battery and change only the cells ? Are you sure that you have 14 cells and not 16 ?I have test my unicycle seated on a chair (on a chair not to fall) pressing the unicycle against a wall with a mulimeter . It goes at 10Ampa instead of 6A ( i have a 350w). In my case when the unicycle reach more than 5amps for a fiew sec the battery switch will cut the power ( witch is very dangerous when you are on the road). There is a switch in the battery electronics to protect the cells. In my case i have fake cells so it's normal that they can't handle the needs.What you need is a battery that as a good C rate first and that match to your electronic battery board. Many unicycle are using samsung, look at Rockwhell or other brands like Solowheel or Airwheel to see whitch kind of battery are used. Samsung ICR18650-22P or 25R they are both good and works better than the 5000mAh fake one that are 1000mAh most of the times.Personnaly i think that you can't use the B one. I won't use the B one because, the C rate is 2. As i'm not a professional i would recommand you to ask you resseler (nlkon) first. The B cell can only support 6Amp wich is not enought for your unicycle, (450w / 60v = 7.5A) you should take a safety in case so look for at least 10 to 12Amps the samsung 25R is great for that.thank you for reading and sorry for my poor English.Jean-Luc Link to comment Share on other sites More sharing options...
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