October 13, 20196 yr I would like to swap my rear fat bike 250 hub motor for 500w for a bit more power going up hill. Can I get away with just swapping the motor? Or do I need to swap any other parts at the same time, like the controller and LCD display Im told the current kit is Bafang! Has anyone else done this before?
October 13, 20196 yr it's a expensive upgrade. The 500W version of the Bafang G06 runs on 48V. You need a new motor, LCD, controller and battery.
October 13, 20196 yr Author it's a expensive upgrade. The 500W version of the Bafang G06 runs on 48V. You need a new motor, LCD, controller and battery. Thanks for the response, why do I need to swap the battery
October 13, 20196 yr Thanks for the response, why do I need to swap the battery that is often the case. You need 48V 12AH minimum to run the 500W G06, better with 48V 15AH. What capacity / voltage battery do you have at the moment?
October 13, 20196 yr Simply getting a 500w hub won't give you any more power as you will still be using the same controller current, your best option is to show us a pic of your controller. A new controller with more current will give you more watts at the wheel ( if the battery is capable ) and you can still keep your existing hub, again show us a pic of your battery and tell us which cells are used.
October 13, 20196 yr Author Simply getting a 500w hub won't give you any more power as you will still be using the same controller current, your best option is to show us a pic of your controller. A new controller with more current will give you more watts at the wheel ( if the battery is capable ) and you can still keep your existing hub, again show us a pic of your battery and tell us which cells are used.
October 13, 20196 yr Ah yes, I now remember your bike was in a thread the other day. Can you post a link again to the bike then we might be able to see what the battery cell specs might be. Your controller is a Bafang compatible one that works with 961 lcd, at 15 amps max is should put out about 430w at the wheel. If the battery was capable you could use a 17- 22a controller for more current but it does need to be Bafang compatible. Until you know the battery specs it could be a waste of time and money.
October 13, 20196 yr Author Specifications 1. Frame: Alloy 6061,Suspension frame 2. Fork: Alloy suspension 3. Handle/Stem: Alloy PROMAX 4. Rim: Alloy 6061# double wall rims 5. Tire:20*4.25inch fat tire, KENDA K1032 6. Battery:36V10.4Ah lithium battery, Removable battery 7. Motor:brushless,DC motor,rear drive 36V250W 8. Display:LCD display, 5 level PAS speed 9. Controller:36V, brushless hall controller 10. Brake:F/R disc brake, ZOOM 11. Derailleur Shimano 12. Hubs: Shaft Hubs + Quick release 13. Front round light included 14. Fenders included 15. Luggage Rack 16. Black wheels
October 13, 20196 yr Author https://www.redrocketlifestyle.com/product-page/copy-of-the-rocket-88-black-with-tan-trim-black-wheels
October 13, 20196 yr Very little spec to the battery except it is 10.4ah which probably suggests it is a 10s4p config and likely uses something like Samsung 26F or J cells in which case the they are maxed out with the current controller.
October 13, 20196 yr Author Very little spec to the battery except it is 10.4ah which probably suggests it is a 10s4p config and likely uses something like Samsung 26F or J cells in which case the they are maxed out with the current controller. Thanks, so would I need a better battery if I upgrade the hub motor ?
October 13, 20196 yr You could probably go to 18 amps OK. In the old days when batteries were crappy - long before we had nice Samsung and Panasonic cells, I often increased the current to 18 or 19 amps without any problems. The increase in current has a proportional affect on torque and power. The good news is that the cost to increase current is zero. You only need to add a blob of solder to the shunt, assuming that you have a wire one. The shunt is normally a wire hoop, like a staple, and it often sits behind the end-plate of the controller, so is easy to access. The idea is to put a blob of solder on 20% of its total length. Sometimes they already have a blob from the factory, so you need to lengthen it to reduce the clear length by approx 20%. Don't overdo it. 30% is about as high as you should go. Here's a picture of one. You can see two blobs, one on each leg, totalling about 40%. If you have a solid state one, you have to solder another one with 1/5 of its value over the top of it. Say you have 05 written on it, you get another one of the same size with 01 written on it. https://www.ebay.co.uk/itm/10-X-SMD-Current-Sense-Resistor-0-001-ohm-2-W-2512-6432-Metric-1-LRMA/391793958859?_trkparms=aid%3D555018%26algo%3DPL.SIM%26ao%3D1%26asc%3D40733%26meid%3D7f32316ae2504f058a30d908d3240752%26pid%3D100005%26rk%3D2%26rkt%3D12%26mehot%3Dsb%26sd%3D352066907374%26itm%3D391793958859%26pmt%3D1%26noa%3D0%26pg%3D2047675&_trksid=p2047675.c100005.m1851
October 13, 20196 yr As I mentioned you don't have to change the hub motor, if you want more power you need more current.
October 14, 20196 yr Listen to these guys, you do not need a new motor. The 'power rating' of a motor is misleading B.S. The power consumed by a motor is determined by what the controller gives it, it's a bit like a tap, you need a bigger tap to get more flow. What vfr400 is suggesting is a freeby workaround, you just need a soldering iron. Nealh is suggesting a new controller that has a bigger tap in it (though this can come with connection complications). However, a bigger tap can only give more flow if the supply capacity is there. This is why the battery is mentioned. Not all battery cells are equal. Some cells are high capacity (bit like a marathon runner), others are high flow ability (bit like a sprinter), but the two don't come together in the same cell. Hence trying to ascertain what cells are in your battery to see if it's capable of giving the higher flow your bigger tap can deliver. Bit of a laboured metaphor, hope it helps.
October 14, 20196 yr 6. Battery:36V10.4Ah lithium battery, Removable battery there is no way you can get the best out of the 36V 250W G06 with this battery leave alone using it with the 500W G06. You can also damage the battery easily when using a low capacity battery. The Chinese grade their motors on the basis of continuous power. If it says 250W on the label, you can pump 250W into it all day, the mass of the motor will dissipate the heat without burning the coils or the sensors. 350W motors have thicker wires, lower stalling resistance. 48V 500W motors have thicker wires and usually have more turns in each coil so gives higher torque at low speed and better acceleration. Typically, when the motor is labelled as 250W, the maximum peak power is double that. Your controller and battery need to be paired to the motor so that they work well together. For example, 250W motor can peak at 500W, the controller should be 14A-15A 36V. 350W motor peaks at 700W, controller should be 18A 36V. This is a popular choice for manufacturers, they simply ask for 350W grade motors for use as 250W. 500W motors are suitable for offroading where you would expect high, short gradient, high acceleration. The controller would be 48V 20A. If you have a 36V 15A controller, then choose a battery which does not get damaged at that current continuously. That's belt and braces. As a rule of thumb, 1.5C. If C is 10AH for the battery, then 1.5C is 15A for the controller. If your motor is 250W then 36V 10AH is the minimum required. If you want 500W motor then you'd need 48V 14AH.
October 14, 20196 yr there is no way you can get the best out of the 36V 250W G06 with this battery leave alone using it with the 500W G06. You can also damage the battery easily when using a low capacity battery. The Chinese grade their motors on the basis of continuous power. If it says 250W on the label, you can pump 250W into it all day, the mass of the motor will dissipate the heat without burning the coils or the sensors. 350W motors have thicker wires, lower stalling resistance. 48V 500W motors have thicker wires and usually have more turns in each coil so gives higher torque at low speed and better acceleration. Typically, when the motor is labelled as 250W, the maximum peak power is double that. Your controller and battery need to be paired to the motor so that they work well together. For example, 250W motor can peak at 500W, the controller should be 14A-15A 36V. 350W motor peaks at 700W, controller should be 18A 36V. This is a popular choice for manufacturers, they simply ask for 350W grade motors for use as 250W. 500W motors are suitable for offroading where you would expect high, short gradient, high acceleration. The controller would be 48V 20A. If you have a 36V 15A controller, then choose a battery which does not get damaged at that current continuously. That's belt and braces. As a rule of thumb, 1.5C. If C is 10AH for the battery, then 1.5C is 15A for the controller. If your motor is 250W then 36V 10AH is the minimum required. If you want 500W motor then you'd need 48V 14AH. In principle, that's right, but we know from actual experience gained over many years that there wouldn't be any detrimental affect from soldering his shunt a bit. I've personally run 250w ebike motors that came with 24v 12A controllers at 48v and 18 amps without anything burning or going bang. That's 3 times as much power! Here, we're talking about 20% more. It's similar with batteries. It's true that the lower the current you use, the better it is for the battery, but the battery won't die if you run it with higher current. In the worst case, you'd exceed the rating of the BMS, which would be something like 20 or 25amps, then it would self-protect and cut out. I think in OP's case he wouldn't care if his battery life is reduced from 3 years to 2 years and 10 months for the sake of a bit of extra power. That's his decision.
October 14, 20196 yr Controllers don't have loop wire shunt for many years. They are all SMD now. When did you see one of them last time?
October 14, 20196 yr In the worst case, you'd exceed the rating of the BMS, which would be something like 20 or 25amps, then it would self-protect and cut out. I think in OP's case he wouldn't care if his battery life is reduced from 3 years to 2 years and 10 months for the sake of a bit of extra power. That's his decision. batteries often die of accidental deaths. It's the law of small probabilities. He'd be lucky to get away with just a blown fuse but more often than not, a blown fuse will end up as a dead battery.
October 14, 20196 yr Controllers don't have loop wire shunt for many years. They are all SMD now. When did you see one of them last time? Why are you being so contrary? Loads of controllers have wire shunts. Just because yours have changed doesn't mean everyone else has. Even so, I told OP how to deal with solid state shunts, which give more accurate results than soldering wire ones and is just as easy, though cost a couple of quid for the shunt. Edited October 14, 20196 yr by vfr400
October 14, 20196 yr Author You could probably go to 18 amps OK. In the old days when batteries were crappy - long before we had nice Samsung and Panasonic cells, I often increased the current to 18 or 19 amps without any problems. The increase in current has a proportional affect on torque and power. The good news is that the cost to increase current is zero. You only need to add a blob of solder to the shunt, assuming that you have a wire one. The shunt is normally a wire hoop, like a staple, and it often sits behind the end-plate of the controller, so is easy to access. The idea is to put a blob of solder on 20% of its total length. Sometimes they already have a blob from the factory, so you need to lengthen it to reduce the clear length by approx 20%. Don't overdo it. 30% is about as high as you should go. Here's a picture of one. You can see two blobs, one on each leg, totalling about 40%. If you have a solid state one, you have to solder another one with 1/5 of its value over the top of it. Say you have 05 written on it, you get another one of the same size with 01 written on it. https://www.ebay.co.uk/itm/10-X-SMD-Current-Sense-Resistor-0-001-ohm-2-W-2512-6432-Metric-1-LRMA/391793958859?_trkparms=aid%3D555018%26algo%3DPL.SIM%26ao%3D1%26asc%3D40733%26meid%3D7f32316ae2504f058a30d908d3240752%26pid%3D100005%26rk%3D2%26rkt%3D12%26mehot%3Dsb%26sd%3D352066907374%26itm%3D391793958859%26pmt%3D1%26noa%3D0%26pg%3D2047675&_trksid=p2047675.c100005.m1851 Thanks for this, I will take the controller apart and have a look. Is there a better controller I can buy? I live at the top of a big hill and the bike really struggles to get up
October 14, 20196 yr Take the end-plate off (4 screws) and have a look inside. There's no need to open the whole thing until you've checked that. In most cases, the shunt is sitting there grinning at you, just waiting to be fed with a blob of solder. Edited October 14, 20196 yr by vfr400
October 14, 20196 yr Why are you being so contrary? I don't think I am, at least consciously. Lishui for example will always refuse to push their controllers as far as KT. They won't let me have more than 18A from their 6-FET controllers for example, albeit than KT will let me have up to 20A. When I looked at his spec list, his battery is the weakest link. The cells weren't specified suggesting that they should not be pushed too much. Even Samsung 29E cells should not be pushed to 2C, Panasonic even a bit less. It's clear that his 36V 10AH battery is the weakest link. If he pushes on the current, it will just sag more and risk oherheating.
October 14, 20196 yr I don't think I am, at least consciously. Lishui for example will always refuse to push their controllers as far as KT. They won't let me have more than 18A from their 6-FET controllers for example, albeit than KT will let me have up to 20A. When I looked at his spec list, his battery is the weakest link. The cells weren't specified suggesting that they should not be pushed too much. Even Samsung 29E cells should not be pushed to 2C, Panasonic even a bit less. It's clear that his 36V 10AH battery is the weakest link. If he pushes on the current, it will just sag more and risk oherheating. It'll be absolutely fine at 18 amps.
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