How to power down my Bafang BBS02

[judson]

Hey all,

I'll try to make a long story short. The first battery I bought to use with my bafang mid-drive was a 11.6Ah 48v in a dolphin case with a physcical on/off button integrated into the case. I like this battery but I need it for another project. The battery I want to replace it with is a 13.5Ah 48v in a jetpack case with NO on/off button.

In my old set up, i would power on the battery by pressing the physical button then press and hold the on/off button next to the PAS controls. So here is my question, if I replace this battery with one that doesn't have a physical on/off button, will the software on/off at the handle bars suffice to power down the system? or will some thing still be 'on' somewhere?

It is a bit confusing because these units have an integrated controller. My worry is that even if the display is off, the controller would be drawing power.

Thanks for any thoughts!

 

[dogman dan]

Unplug always works. I'm not so familiar with the BBs02, but power down the display, and the controller will be powered down.

I'd still unplug if parking with a really empty battery, or parking for a week or so.

 

[Ykick]

BBS01/2 use typical Chinese controller ignition setup. Whenever power’s available there’s a very very small current uA’s for the soft power button on the handlebar control.

Once powered up there’s slightly more drain but it also has a timeout setting which will shutdown to standby after a preset time.

I wouldn't leave it plugged in to an active battery for "ages" but I'm fairly confident a month or so wouldn't hurt anything. Even on a partially empty battery pack.

 

[judson]

Well this seems to be great news. I have another system that I am building up with a Cycle Analyst v3 and I need the battery level on/off switch for that.

So on this bike (which I ride very regularly) it sounds like only powering down the display only will result in just a minor level of lost juice and that would be over an extended period of time.

I think for safety's sake I will leave the battery connection in a reasonable place, or for long term storage.

Thanks!!

 

[craneplaneguy]

I'm using a DC rated breaker, that can function as a switch as well. I'm familiar with them from solar work, I chose a 60 amp one, for my BBHD build. It will be hidden just enough to a theft deterrant also. At least they'll have to pedal or carry it! I'll post a link later.

 

[craneplaneguy]

About 20 bucks or less, 2 by 3 inches more or less, a couple ozs. Good and easy mechanical connection with the mounting lugs, and 1/4"/28 threaded studs for the electrical connections, very robust. I'm going to mount mine on one end of my battery box, so super short connections, and hide it with a little rubber flap from any E-bike thieves.

 

[judson]

That's a nice looking switch, where did you purchase it?

 

[craneplaneguy]

https://www.colemanair.us/vp_asp/scripts/shopexd.asp?id=695

Besides being a stealthy way to kill the battery, it of course gives you some protection downstream from inadvertent shorts or whatever. Having it "hot"/unprotected is not how I wire a solar system, and frankly I'm a little surprised that all these hot rod batteries on bikes that get tipped over, crashed, and otherwise ridden hard, don't have some provision for protection, as close to the battery as possible. That's also how we do it in the aircraft world, we use a master switch as close to the battery as practical, so when we come in to crash all the wiring is dead

Summit Racing has some mechanical cheap master switches, but they don't offer any over current protection. I assume the 60 amp one is enough, more then enough, if I blow it under normal use I'll get a bigger one, they are available in 10 amp increments I believe.

 

[Alan B]

Do not exceed voltage ratings of these breakers. This one is rated at 48 volts.

 

[craneplaneguy]

Good catch! That slipped by me, I'll use it anyway until and if it burns out or whatever. Then I'll replace it with a higher voltage rated DC breaker from Outback (a solar gear provider), they have them up to 300 VDC.

 

[craneplaneguy]

Something like this: http://www.backwoodssolar.com/panel-mount-60a-dc-breaker-60

 

[Rassy]

I like to use the dc toggle switch circuit breakers that are often used on bigger electric scooters. On this page there is a choice of 32 or 63 amp models, your choice, for $11.95 USD. Some of mine are older than my time on ES and I've never had one fail, but have never exceeded 60V (i.e. 48V Ping batteries, etc. They handle the "spark" when the controller is fired up and are also handy for adding accessory wires since they are built just like a household ac circuit breaker:

http://www.electricscooterparts.com/circuitbreakers.html

 

[craneplaneguy]

I like it, less expensive as they don't need to meet the UL/"certified " regs as the solar DC type breakers. They need to pass building codes and all that entails. But the scooter types look plenty good enough for our use, can't beat the price, cool.

 

[judson]

About 20 bucks or less, 2 by 3 inches more or less, a couple ozs. Good and easy mechanical connection with the mounting lugs, and 1/4"/28 threaded studs for the electrical connections, very robust. I'm going to mount mine on one end of my battery box, so super short connections, and hide it with a little rubber flap from any E-bike thieves.

For whatever reason (mostly aesthetic I suppose) I think I prefer these. How big of a deal is it that their max VDC is 48V? I am using a 48V battery so I am running right up against this limit (if not over a bit) especially fresh off the charger.

Amperage seems fine at 60A.

 

[craneplaneguy]

I'll find out how they work on a 52 volt battery, I'm guessing (and only that), "close enough". But I appreciate it being pointed out they are rated for 48, so, buyer beware. I should have caught that before bragging them up. 52 vdc is still kinda an oddball voltage, as compared to 12/24/ and even 48. 52 probably never came into the mix when setting a max rating for them. Off grid solar systems nowadays, are almost all 12,24, or 48vdc. If nothing else, these are mechanically robust, easy to secure well, plus the 1/4" studs for ring terminal connections, making a secure wire connection easy.