BBSHD build and 0.7H error

[GameOverMan]

Hello guys and girls,

I'm in the process of building an ebike fatty. Bought everything off aliexpress bbshd and 52v 27mah battery and was very exited when I assembled everything but got an error.
It's 0.7h over volt protection. I was sure after reading forums that 52v battery will work on bbshd but this one give me issues. I bought a programming cable thinking that will help me remove the protection but I couldn't find any settings like that in the program.

Any one has experience with this? Is there a way to reprogram it? My battery tests at 58.2v right now.

Have no clue but any suggestions would help.

All best!

[Defjr333]

I really hate to give you bad news, but Aliexpress was the big mistake. A coworker bought a BBSHD and battery pack from them and had the same issue. In the end it was determined (thanks to Luna's help) that the controllers they ship ONLY support 48v, NOT 52v!!! Luna gets specific controllers and some upgraded internals compared to Ali and the cheaper guys (thats why its cheaper), if I am not mistaken. Try to get the pack to under 54V (fully charged 48V pack is 54v, a 52v pack is 58.8V) and I would bet the error goes away. If you do not want to switch to a different battery pack you could order a replacement controller from LUNA and be good to go.

[GameOverMan]

Uh that sux I was on the budget to begin with. Do you think there is a way to open it up and replace any of the components in it so it can accept this voltage?

[Defjr333]

There ARE people that change the FETs and stuff inside to allow higher voltages, BUT it is a ROYAL PAIN. Just getting all the potting(silicon) picked out to get to the circuit board takes some serious patience and time.There are tiny wires and many hazards that will ruin it if you make one wrong move. I understand the $ thing, but unfort the controller is pretty hard stuff to do. I think Luna sells them for $150 and those DO allow 52v packs. Sorry couldnt give you some better news.

[GameOverMan]

There isn't even any for sale right now that would fit my motor ver.B that is. I couldn't find anything about this on the internet. do you happen to know any resource how to change the FETs?

[Defjr333]

Just looked at Luna's page for the controller, at least I was wrong on price, and its only $100(vers A only in stock). I am an Ex Aviation Electronics Tech from the Navy. I repaired Radar and Communications Systems on F16s. I ATTEMPTED to do as you are thinking for my coworker on his. But after a half day of picking silicon out of his(to see what FETs where in it to order larger ones) I realized the price of the upgraded FETs and new potting, it was going to cost around $60/70! So he (thankfully) came around to just buying it from Luna. He has had NO issues since. IF you do the FETs you void any warranty as well. If it were me, I would either wait for ver B to be in stock, or buy ver A and just swap(cut and solder) the connectors inside(thats the only difference between A and B. Just my $.02

[tommyn]

See here https://endless-sphere.com/forums/do...2446&mode=view

[GameOverMan]

gotcha,
Is there an option to lower voltage somehow either through cutting out some of the battery cells or maybe a device that would do that?

[Defjr333]

That is a good question. Yes it is technically possible. There are step down converters of various sizes that take 48-70v DC and convert it down to lower voltages with higher amps. MAY be an option, I use one for running lights, audio, video, and alarm on my new build. I would search for "52v DC to 48v DC puck converter" and see if they are financially the better route. Unfortunately u cannot just disconnect cells to lower the voltage as the internal BMS will freak out not seeing those cells and the much lower voltage. U could also rebuild the pack with a smaller BMS for 48v. But all these cost $ and lower the top performance of the motor/ bike. I personally would just save up for the controller and swap it out. Hope this helps