rode over my lipo battery at wot

[whereswally606]

More changes to the bike.

I should have taken a few pics but weather is lousy here, will maybe upload some tomorrow.

Anyway this morning I decided that Id like to sling the bike into my girlfriends car so i could go to the farm where she shares a horse and go for a horse/ebike ride. I thought to make my life easier when I'm doing this i would make the connectors to the hub motor nearer the rear wheel so that i can just quickly remove both my wheels to make putting the bike in the car a very easy maneuver. I started to take the wheel off and the Dr Bass torque plate which id glued with a aircraft glue by hankel just fell off. this was the side which i had put no bolt into.

from there my day got worse and worse.

thinking I should fix this and not go riding i looked into buying a drill bit capable of going through the dr bass metal. I know the last time i did this i ruined plenty of bits and it took hours so my day was never going to be a fun one.

I went out to the local B&Q and bought some HSS drill bits in a pack. 30 minutes later i was back at the store getting a refund after snapping the bits. Then i bought a titanium bit. Together with this and a different ruined bit I spent two hours swapping bits to make tiny differences to the hole. (one bits would cut a central hole, the titanium would level the hole again.

I managed also to burn out my black and decker pillar drill.

broke the titanium bit (on purpose with my angle grinder to get a better head)

broke the other HSS bit earlier.

but I did finally make a hole in the torque plate. managed to drill the swing arm in the correct place. set the bolt through both and reapplied some of the aircraft glue. (more confident that with the bolt I might be okay for longer but I conscious to check it more often now)

other changes, I moved the controller to hang in the space within the frame. I finally got around to the wire mod of putting the disconnect near the hub.
A few weeks back I made a throttle reducer in a nice hobby box I tried to improve it by cutting the shaft of the 10k pot with my angle grinder but in doing so i probably made it so hot i broke that too. Anyway I scared myself cause i had no idea at first that the problem was with the throttle or with my soldering the hall and phase wires to the hub. I was pretty sure I buggered up the throttle device to i messed around with it with the bike upside down and the bike worked intermittently. Kinda of a relief but it does mean i need to make another now (at least buy another 10k pot). very frustrating.

I did however have a nice meal at the curry house with my little god son Max and his parents and their parents so not a completely terrible day.

[whereswally606]

Warning largish post ahead,

amazing day today, got to ride in Dorset to a local airfield up a large hill called Winn Green. very steep, went past a couple of lycras on racers on the hill who were left in my dust so to speak. Drain Brain showed 38 Amp max and I saw peaks of 2500w through my cheap GM motor. The hub was warm after the hill, wished I had internal temperature sensors on my stators and my controllers fets.

Lycra clads found me at the airfield later and were actually pretty complimentary, I admitted it was cheating but they conceded they couldnt take theirs offroad.

So after my fix of the Dr Bass torque arms (ie drilling fiasco previous post) my handy work seems to have held well today. Also relocated the controller inside the mid of the frame where it fits nicely and cleaned up a load of shoddy wiring. Also fixed the throttle limiter (replaced 10k broken pot with 5k pot).

So after I made it back from the airfield today back to my girlfriends farm the batteries were at 68volts, 66.6 being where all would have 3.7v my drain brain said id used 5.6 Ah and my packs are 40c 4ah 3s packs but configured so i have 18s 8Ah.

I have a feeling my bike is not as efficient as Id like, and that I need a bit more battery to cope with the issues. I love the power it has but the top speed is just more than its worth pedaling with. on my other bike I have a GM external controller which has great smooth regen which I lack on my hua tong controller. Since I have a busted one of these GM controllers which i intend to fix I might step back from 18s down to 14s, this is because
a) at 14s the top speed at WOT will be a better match to pedaling,
b) this in turn should be more efficient since pedalling will make a difference and I wont have to pulse the throttle,
c) my hyperion can be used to its full potential
d) I have some extra 3s packs (4 of them) out of which i can make 2s packs to combine with my 3s to make 14s
e) I can then have a 14s 3p 12ah pack
f) the pack should have less Voltage sag and last more cycles.
g) If i get the GM controller working I can have regen
h) 12ah * 2c = 24 which means my bulk charger project will cost less and be within the amp limit
i) 21s 2p is possible with a battery rejig which can bring me back to fun/non-commute times on occasion
j) can monitor the cells with two BVM8s

reasons not to convert to 14s
1) time and effort
2) have to mod the hua tong to take lower voltage cut off, (unknown consequences of how the ebrake will perform)
3) configuration of the battery in the diy B&Q box has no space for extra 2s lipo in the width meaning a complete rethink
4) I like riding really fast and having the crazy acceleration, mitigated slightly by point (i)
5) cheaper chargers (which i dont really intend to use) will be a pain to use.
6) 14 is not a good divisor of 6 for handy balancing battery medics.

Im probably gonna go down this road in the near future as the other spare 3s packs are sat deteriorating and if i am careful I can do this right.

thanks for reading all this, comments are welcome.

[whereswally606]

so new news.

The week before last I was down at my girlfriends farm in Dorset. This seemed a perfect opportunity to meet another UK ES member Burtie. We arranged a ride to a local pub and then went back to his for a BBQ. Pippa and I enjoyed every minute and Burtie was an excellent host. He has also given me several ideas for my next build.

Anyway the other thing I wanted to show today was my biting the bullet and inspecting the inside of the lipo pack I have (when i say inside i just mean taking off the blue wrapping and inspecting the terminals)

dodgy lipo tab.jpg (135.45 KiB) Viewed 233 times

Its not very clear but it looks like the cathode tab of the battery is not actually in the pouch and that the spot crimps are coming away from the pouch of the pack. I thought i might have a loose balance tap before seeing this but I doubt the cathodes are supposed to be loose like this. Not sure what to do with this cell. I have an idea to buy up some 2s cell like the 3s cells i have to upgrade my entire pack to 14s from 12s, this can become one of those 2s cells by a removal of the last cell.

Is it worth talking to HK about this? I know ive voided the warranty by doing this and I way past the time anyway.

thanks for reading.

[whereswally606]

So yesterday I went all out on repairing the batteries i have. I have isolated 3 of my 3s packs which have one weaker cell.

Going to go down to 12s this way i can use all 16 of my 3s packs. I intend to have the weaker ones in a 12s string on my handle bars but this way im up to 12s4p which is 16ah of 40c lipo. bought a piece of wood to act as a frame insert to my pvc duct box. this should make servicing the battery far less damaging.

anyway bought a battery medic from hobby king. measuring the same pack simultaneously with a celllog 8s the battery medic was way off. And it also didnt appear to do any discharging or balancing. my turnigy 3s/2s 0.3amp balance charger did a better job.

lastly my battery box was not well protected last time i went riding with the girfriend and her horse. the terminals of a few batteries got damp and some cells ended up very unbalanced. I was relating this new to my sister and mother who were on there way out shopping. on there return they bought me a pingi. A pingi is like a rechargable (via microwaving) silca pack which basically acts to suck the moisture out of the air, like what you get with your new trainers/sneakers. i have the lipo now in a flightcase with the pingi for one week prior to my battery rebuild.

no other news so far. oh apart from i am almost done on building my modular bulk charger.

[whereswally606]

I had been running this norco team race with lipo in manrose B&Q diy ducting for sometime. The plastic white clips where not really cutting the muster, I and for that matter my girlfriend whose bike this has become did not feel safe enough.

after reading Kingfish's stinker thread about his lipo i thought it was about time to check mine which are all paralleled at the cell level first then series. turns out they are all fine which is surprising since one im pretty sure used to be self discharging a while back.

Faster charging modification.
after checking all the cells at the cell level i put an extra wire in the main larger battery box. the purpose of the extra wire was to decouple the 3s from the 9s string so that I could further parallel the two 6s halves of my 12s battery. I run 12s4p giving 16ah. I recently built a server/meanwell clone bulk charger which will do lots of amps however the end of the charge sees less and less amps which is when i switch over to the bc168 (hyenas 6 cell wonder charger). but before i needed to do each half of the pack separately whereas now I can disconnect the wire so the battery becomes effectively 2 6s4p batterys and plug the into the paraboard which came with the bc168.

So i bought some roofmountable cycle racks of ebay. they are good thule ones for £8.50 each. I plan to mod the front holder to take a 20mm pipe clamps for the front axles of my bikes. Unfortunately today i realised that I couldnt quickly take the battery rack i had built off. My plan was to mod some pipe clamps i had holding my other battery on my scott ransom. I thought it was probably overkill having 4 on them and i couldnt really afford to buy any extras so i gambled and took them off. In doing so i actually found that i could secure the scott ransoms battery a bit more securely (one more bolt to the plate. I have made that bike a few grams lighter. I used some wood hole saw drill bits to enlarge the hole in the clamp. my tools are so basic but the outcome was really good.

once i was convinced about the new strength of the mount i decided to put all the batteries under the downtube in one block. this has the bonus that they are easy to remove fast from the bike in the event of a lipo incident. Also the bike is so light without the battery that it works well as a non ebike should the need ever arise.

The white cables (phase wiring) is proper over kill. Its the wiring out of a wrecked honda insight (not mine thank god)i had to enlarge the 4mm diameter holes in the strip block to jam it all in and even then it was a struggle. (lesson here is buy enough cable before you start working on your bike) mind you I had it lying about and it was wasting not being used.

anyway a photo of the end product so far.

whole bike


the close up

[whereswally606]

Today i converted a magic pie controller 328 pcb internal to a bac281p external.

why?

My external one blew a mosfet and a small transistor taking with it the traces too. i had already repaired it once. anyway I wrote to golden motor who kindly sent me the internal one by way of replacement for the cost of shipping (which was £16) anyway it got here in about a week which i unbelievable for stuff from china but i was well surprised. better yet i could install it in time for ebike holiday next week wit h the missus.

so it turns out this is not a straight forward mod for several reasons

1) you need to desolder the connectors off the broken one and solder them to the new one

2) the caps are on the other side of the pcb on the internal version so they need desoldering and resoldering the other side

3) the smaller cap on each phase are slightly larger form factor than on the external boxed version. i could have used the caps from the broken one but i thought inside it would be easier to drill the cover to accommodate the larger caps. turned out very well.

once i had it in a similar state to get it tested i trialled it on the scott ransom which has the identical system so it was an easy case of unplugging one set of leads and plugging in the other. It worked which was a relief since i was about 3 hours invested by this point.

now i just had to install it onto the norco. Using some padding and zip ties i held it in place in the space within the frame upside down.

Making up the other cables again took a long time. extending the hall wires, making up the spade terminal connectors and fixing up the wiring harness all took a while.

last thing i have to do here electrically is make a 2 stage switching system for my antispark resistor switch. that can wait another day.

will post photos tomorrow but there is not much more to see. I would say if someone asks you to convert a internal magic pie controller into the external one that it can be done but maybe it a huge pain in the arse to do so. As it stands now i have two potential controllers for the holiday. but at least now she can have proper regen.