1000W Ebike Battery Build DIY & 3D printed case, fits Bafang — Transcript

Full transcript

1. 0:00what's going on YouTube hope you've all
2. 0:02been well I know it's been a while since
3. 0:04I posted my last upload but that's
4. 0:06because this video has taken so damn
5. 0:08long to make so I hope you guys enjoy
6. 0:10this this is how to build your own ebike
7. 0:13battery so we're starting from scratch
8. 0:15here we're going to talk to you about
9. 0:16sourcing batteries um spot welding
10. 0:20soldering wiring up a BMS um about uh
11. 0:24batteries battery testing um we're even
12. 0:27going to uh design and print a case for
13. 0:30these batteries here the the files will
14. 0:32be in the description um and this is
15. 0:34going to fit right into our high long
16. 0:35battery bracket and that's the one that
17. 0:37comes with your buang conversions that's
18. 0:39what we did in the last video is we made
19. 0:41this uh DIY ebike this is the buang
20. 0:45bbs02b um so we walk you through the
21. 0:47full guide of how to build it so please
22. 0:49check that out like And subscribe and
23. 0:52I'm excited for this video because this
24. 0:53one took a long time to make so let's
25. 0:56jump right into it without further Ado
26. 0:58step one sourcing batteries
27. 1:00now honestly half the battle is finding
28. 1:0218650 batteries I mean there can be a
29. 1:05lot of fakes online or uh you know
30. 1:08Customs clearances you have to worry
31. 1:09about um it's not the easiest thing but
32. 1:12I I went the roote of marketplace um for
33. 1:15cost they were much cheaper than buying
34. 1:16new I think I picked up my batteries
35. 1:19were like a125 a piece luckily I found
36. 1:22this guy who was selling a bunch of
37. 1:23these uh packs I believe they were from
38. 1:25like a medical device that had to be
39. 1:27changed every you know number of years
40. 1:30and uh a few of them were actually full
41. 1:32of Samsung cells which was nice um but
42. 1:35most of them were Sano so each battery
43. 1:37has a code on it right and and you'll
44. 1:38look up that code for the uh this data
45. 1:41sheet here specification data sheet and
46. 1:44there's information you want on here to
47. 1:45see if this battery is suitable for your
48. 1:47for your project so one of those is
49. 1:50capacity there's what I've got
50. 1:51highlighted so these are about uh you
51. 1:53know 2.5 amp hour capacity you also want
52. 1:57to check the charge current and and uh
53. 2:00of course you want to check the
54. 2:01continuous or Max continuous discharge
55. 2:04current um because you know that will be
56. 2:07tell you if it's suitable for your
57. 2:09project or not so here I've got a mock
58. 2:11battery drawn up in Fusion 360 just to
59. 2:14show you the configuration of what we're
60. 2:16going to be doing here so we've got the
61. 2:18positive terminal here with the little
62. 2:19button top and then we've got the
63. 2:21negative terminal right beside it so you
64. 2:23can see these batteries are just
65. 2:25staggered one up one down and you can
66. 2:27also see that we've got a row from right
67. 2:30to left here of batteries that are
68. 2:32hooked up in parallel connection so
69. 2:35parallel means the positive to positive
70. 2:37and negative to negative so the voltage
71. 2:39stays the same obviously but the current
72. 2:42adds up right and then if you look
73. 2:45lengthwise we've got batteries hooked up
74. 2:47in series configuration so series
75. 2:49configuration would be from the positive
76. 2:51one to the negative of the next and so
77. 2:54on so that adds up the voltage but the
78. 2:58the current and Capac capacity stays the
79. 3:01same and we can see that each of these
80. 3:03cells can output 5.2 amps continuously
81. 3:07Max discharge rate so if we do a four
82. 3:11parallel configuration and that would
83. 3:13stack the current output and keep the
84. 3:16voltage the same then we can take uh 5.2
85. 3:20continuous discharge current amps and
86. 3:22times it by four parallel which would
87. 3:24give us 20.8 continuous amps discharge
88. 3:29and of we recall that power equals
89. 3:32voltage time current and we know that
90. 3:34our voltage will be 48 volts we can take
91. 3:3748 volt * 20.8 continuous discharge
92. 3:41current amps and then that will give us
93. 3:44our power of our battery which would be
94. 3:53998.50 watt but it can actually handle
95. 3:56much higher like 1,400 Watts Peak power
96. 3:59so technically we are not maximizing the
97. 4:01capability of our motor since our
98. 4:03battery can't output the maximum wattage
99. 4:07that our ebik can handle all right now
100. 4:10I'm sorry to bore you to death let's
101. 4:11move on to step two and here we're going
102. 4:13to test the batteries that we picked up
103. 4:15this step is very very important so I'm
104. 4:18using a letoa charger here and this
105. 4:20charger is special because it can charge
106. 4:22your batteries up and then it uses a
107. 4:24resistor to drain your batteries and it
108. 4:26gives you a screen reading of the actual
109. 4:29capacity of your batteries and then
110. 4:31it'll charge them back up to full charge
111. 4:33um so you want to that's what I have
112. 4:35written down on the batteries here is
113. 4:37their milliamp hour capacity so record
114. 4:41the values and then it'll charge them
115. 4:43back up to full and then I left them for
116. 4:46a week and that's what you can see here
117. 4:48I'm doing I'm coming back and I'm
118. 4:50testing the voltage and I'm looking for
119. 4:52any batteries that have lost voltage
120. 4:54over the week you also want to look for
121. 4:56batteries that have visual cues of
122. 5:00batteries that heat up during charging
123. 5:02or heat up during discharging
124. 5:04excessively now you can also use
125. 5:06something like this to test your
126. 5:07batteries this gives you a valuable
127. 5:09metric because this can test for
128. 5:10something called internal resistance
129. 5:13however units like this I've heard are
130. 5:14not very reliable with each different
131. 5:17cartridge showing a different internal
132. 5:19resistance for even the same battery and
133. 5:21sometimes even testing the same battery
134. 5:23twice will give you different internal
135. 5:25resistance now the more you spend
136. 5:27obviously you get what you pay for so so
137. 5:29you can check out something like this
138. 5:31this is a valuable thing to check
139. 5:33because one battery with high internal
140. 5:35resistance will pretty much render your
141. 5:37whole pack um your whole battery pack to
142. 5:40be quite limited there is a method where
143. 5:42you can check internal resistance using
144. 5:44a resistor in this formula so if you
145. 5:47check the voltage of the battery with no
146. 5:49load and then apply a known resistor you
147. 5:52can use this formula to check the
148. 5:54internal resistance and of course like I
149. 5:56didn't want to spend more money on this
150. 5:58project it already cost me a lot a lot
151. 5:59of money in time but this is definitely
152. 6:01something I would
153. 6:03recommend all righty now moving on to
154. 6:05step three we're going to assemble our
155. 6:07battery so I went but with this plastic
156. 6:10structure here you can pick these up
157. 6:12pretty cheap online I would definitely
158. 6:14recommend using something like this you
159. 6:16definitely don't want to hot glue gun
160. 6:18your batteries together it's not good
161. 6:19for them with the heat um I like this
162. 6:22one because it was Square so it would
163. 6:24make the spot welding easier you can go
164. 6:26with something like this and that's what
165. 6:27I'll use in my next build where you can
166. 6:29get a more compact kind of diagonal fit
167. 6:32um that's definitely good for cramming a
168. 6:34lot of batteries into a small space but
169. 6:36it made a spot welding a little harder
170. 6:38so just decided to keep it simple so now
171. 6:41I'm going to really clean off all the
172. 6:43nickel strips that was previously on the
173. 6:44batteries you want these terminals
174. 6:46really clean right so your your nickel
175. 6:48strips your plated nickel lies really
176. 6:50flat and that's going to assist in spot
177. 6:52welding so here I'm just putting them in
178. 6:54one row up one row down and then I'm
179. 6:56just compressing it all down this stuff
180. 6:58is super easy and there's even cutouts
181. 7:00for the little spot weld so moving on
182. 7:04let's go on to step four here's where
183. 7:06we're actually going to spot weld the
184. 7:07batteries together so here is where you
185. 7:09actually need to start being careful
186. 7:11because now is when stuff can actually
187. 7:13start to get dangerous so here I'm
188. 7:15making some of the first spot welds I'm
189. 7:17using a little battery powered spot
190. 7:19welder as you can see right here I'm
191. 7:21just putting in some spot welds I was
192. 7:23spot welding up the parallel packs here
193. 7:25and then now I'm doing the series
194. 7:27connections take note that I labeled
195. 7:29quite clearly the bottom of the battery
196. 7:31and the top and then also note that I
197. 7:33also labeled um 1 to 13 so organization
198. 7:38is really huge at this stage of the game
199. 7:40if you connect two batteries together
200. 7:42that aren't supposed to be connected and
201. 7:43create a short circuit this can be very
202. 7:45dangerous so really pay attention to
203. 7:48organization here this little glass Ikea
204. 7:50table came in so handy here because I
205. 7:52could look right through it and see my
206. 7:54tablet now here's a product that you're
207. 7:56supposed to put on top of the positive
208. 7:58terminals which just gives the battery a
209. 8:00little more protection from shorting out
210. 8:02to the negative which is actually pretty
211. 8:04close to it I skipped on using these
212. 8:07because they were taking forever to ship
213. 8:08but I do recommend using those it just
214. 8:10add that added layer of protection and
215. 8:13there was even one point in my build
216. 8:15where I got a little sloppy doing this
217. 8:17over and over and actually had a bit of
218. 8:19a short and that all could have been
219. 8:21prevented just by using these stickers
220. 8:23right this on the right here is an
221. 8:25option of a different spot welder now
222. 8:28this one connects to a car battery and
223. 8:30it's on its way I'll be posting a video
224. 8:31about this to see how it works I believe
225. 8:33that something like this should have a
226. 8:35little more power and my spot weather
227. 8:37that I used was good but I feel like it
228. 8:40could be better all right moving on
229. 8:42let's go to step five now we're actually
230. 8:44going to wire in the BMS so the BMS is a
231. 8:47battery management system and it
232. 8:49controls that batteries don't get too
233. 8:52high charged or too low charged since we
234. 8:55obviously have many batteries in this it
235. 8:57controls each one it's kind of like the
236. 8:58brain of of the entire battery managing
237. 9:01things like temperature cut off cut in
238. 9:04ETC so here you can see I'm trying to
239. 9:06wire in the anode or cathode of the BMS
240. 9:09the main negative or main positive I
241. 9:11should say and this was that bus bar I
242. 9:13was talking about how I was trying to
243. 9:14fold the nickel strips around it and
244. 9:17then feed solder in which wasn't the
245. 9:19best idea so now here's a wiring diagram
246. 9:22on the right and you have to wire in the
247. 9:25individual leads in between the series
248. 9:27connections so here's a close diagram it
249. 9:30looks a little complicated but it's
250. 9:32really not that complicated once you
251. 9:34once you take your time um so now after
252. 9:37all the leads were wired in I was just
253. 9:39applying some capton tape and here I'm
254. 9:42just testing before I actually plug it
255. 9:43in that I actually wired these right so
256. 9:46if you test it each lead when you go to
257. 9:48the next in series next in line I should
258. 9:51say it should increase by one nominal
259. 9:54voltage which would be about 3.6 volts
260. 9:57so just to finish up the wiring I add
261. 9:59added this XLR connector I believe it's
262. 10:01called and an xt60 connector so I can
263. 10:04connect it to my bike now here's a
264. 10:07little closeup of the BMS I used it was
265. 10:09a gabata I think you say or a jbd I was
266. 10:12going to cheap out on a BMS and then
267. 10:14somebody on a Facebook group recommended
268. 10:16that I get one of these and said they
269. 10:18were really good and so far I like it
270. 10:20it's been great and there's an app
271. 10:22support so I can look inside and see
272. 10:24exactly what's happening with the state
273. 10:25of my battery no complaints as of
274. 10:28yet now we're approaching step six of
275. 10:31this whole process we're going to build
276. 10:33the case so I'm getting kind of tired of
277. 10:35this project it's been a lot of work I
278. 10:37could have made it easy on myself but
279. 10:39nope I had to print the case so I picked
280. 10:41up this creality Ender 3 S1 on
281. 10:44Marketplace pretty cheap and I went to
282. 10:46start teaching myself Fusion 360 so this
283. 10:49was after many designs this actually
284. 10:52took quite a lot of work a lot of
285. 10:54prototypes more than you see in this
286. 10:56video and then I had to cut it up into
287. 10:58sections and and printed H so it fits
288. 11:01together like Lego now here's an epic
289. 11:02fail this is how exactly not to
290. 11:05prototype that was in my very early days
291. 11:07that took 53 hours so here was a a
292. 11:10little edit I had to do on the front of
293. 11:11the case when I found out that it
294. 11:13wouldn't actually fit inside my bicycle
295. 11:15I had to go back and kind of put a
296. 11:17little indent in the battery there and
297. 11:19it's just printing up here so now it
298. 11:20actually fits in the in the frame of my
299. 11:23bicycle and then I'm going to glue these
300. 11:25together and it's going to fit something
301. 11:27like this so I still had to figure
302. 11:29figure out how I was going to connect
303. 11:30them I had printed these modules before
304. 11:32I had learned how to do the the screw
305. 11:35with the threaded insert nested into my
306. 11:37prints and even still I find those
307. 11:39little finicky it's hard to get the the
308. 11:41threads going in perfectly straight so
309. 11:43that the screw can go in correctly um
310. 11:45but I went with this little Inlet design
311. 11:47that you just put a zip ties through it
312. 11:49doesn't look as nice but it works pretty
313. 11:51well it would be cool on the next build
314. 11:54to have uh threaded inserts though and
315. 11:56screws holding it together that would
316. 11:57look very professional so this is just
317. 11:59some fish tape it's like a hardish tape
318. 12:02and it adds some kind of impact
319. 12:03protection to the battery I was just
320. 12:05trying to focus on the BMS there's some
321. 12:06wires up there that'll get a little
322. 12:08compressed and then here's some heat
323. 12:10shrink you can purchase this online a
324. 12:12good method is you just wrap a string
325. 12:14around your battery and then you measure
326. 12:16that and that'll give you kind of the
327. 12:17diameter now I didn't have a heat gun
328. 12:20and I also didn't have gloves apparently
329. 12:21um so I was using my stove and you know
330. 12:24it actually worked pretty well you know
331. 12:25make do with what you have when my hand
332. 12:27started to burn I knew it was probably
333. 12:29too hot for the
334. 12:31battery all righty so now I'm just
335. 12:33trying to get it all packed into the
336. 12:34case of course it didn't fit so I had to
337. 12:37print that end again and I'm just having
338. 12:39so much fun with this project if you
339. 12:41can't tell from the sarcasm in my voice
340. 12:44and let's fit it all together I have
341. 12:45little cutouts here I have to solder in
342. 12:47the XLR connector charger I also have a
343. 12:50little digital display that shows me the
344. 12:53level of charge so got these Helping
345. 12:55Hands they showed up on this morning so
346. 12:58it was perfect timing just soldering
347. 13:00these up I thought I sucked at soldering
348. 13:03but then I went out and I actually
349. 13:05purchased higher quality solder and uh
350. 13:07that made a world of
351. 13:09difference popping in the little LED
352. 13:12display here and I'm pretty happy with
353. 13:14how it turned out shows the percent
354. 13:16charge and also the voltage so this was
355. 13:20my method for how I was going to connect
356. 13:21the modules together instead of having
357. 13:24screws which would be more ideal I just
358. 13:26kind of use these like little inlets
359. 13:28here with zip ties this way I if I ever
360. 13:30need
361. 13:31to you know do some maintenance on the
362. 13:34battery I can open it up relatively
363. 13:35easily doesn't look the best but it's
364. 13:38serviceable and these are included in
365. 13:40the 3D print file in the description of
366. 13:42the video all you have to do is print
367. 13:43them out and then drill a little hole in
368. 13:45the module right next to it and you
369. 13:48should be able to zip tie them together
370. 13:49pretty strongly so here you can see me
371. 13:51just fitting the battery onto the
372. 13:53bracket so once again this is the high
373. 13:55long bracket this is the one that comes
374. 13:57with your buang kit um so the fit is
375. 14:00perfect very secure I'm very happy with
376. 14:02it and honestly very happy to have this
377. 14:04over with there was so many prototypes
378. 14:06so much Printing and uh once again the
379. 14:08design the file is in the description so
380. 14:11check that out and print
381. 14:18away all right everyone thank you so
382. 14:21much for watching I know this was a long
383. 14:22one a lot of detail um so I appreciate
384. 14:25you if you got this far um if you guys
385. 14:27hit the like And subscribe I really
386. 14:29appreciate it trying to grow this
387. 14:30Channel and uh really helps out the
388. 14:32algorithm um I'm quite happy to have
389. 14:34this project over with this one took so
390. 14:36much time it was fun but man it was a
391. 14:39lot of work um so in the future on this
392. 14:42channel we'll be doing some tests on
393. 14:44this battery so if you stick around for
394. 14:46that um we're also maybe doing a
395. 14:48makeover on this bike to make it look a
396. 14:50little cooler we'll see what we can do
397. 14:52and also we're going to be testing out
398. 14:54that spot welder so once again guys
399. 14:56thank you so much for the support really
400. 14:58appreciate apprciate it hope you all
401. 15:00have a great day take care everyone
402. 15:07bye