Battery cut off

TLC

New Member
Region
USA
I installed a Bafang BBS02 with a Whale Shark (48volt 20.3AH) battery with a DPC-18 display on my Bacchetta Corsa. I reprogrammed the controller using different ideas from other riders. I did set the Low Battery Protection at 41 volts and Current limits at 18. After reprogramming the bike is just fantastic to ride with the factory setting it was very jerky and kinda scary at some low speeds. At other times didn't even know that it was doing anything. Took the bike out to test the battery, run it down and see when it would cut off. Garmin said I did 72.4 miles with 1774ft of climbing at a moving speed average of 19.8. Near the end of the ride I was riding around 28-29 mph try to use up some battery. Around mile 69 the battery was reading 45 volts jumping down to 44.9. The little battery on the display beside the voltage was almost all black with just a little white showing. Then it shut off, the display went dark, everything off. Rode the next 3 miles back to the car without power. I'm very very pleased with Baffang kit and the battery never expected the speed (had it doing 38.4 on flat ground with 80% power) it has nor the range of the battery. Just curious why did the battery shut down at 45volts,was it the controller or does the battery have so type of protection? Thanks I have enjoyed reading everyone's post I'm new to the e-bike world.
 

Gionnirocket

Well-Known Member
Region
USA
City
Y. O.
I installed a Bafang BBS02 with a Whale Shark (48volt 20.3AH) battery with a DPC-18 display on my Bacchetta Corsa. I reprogrammed the controller using different ideas from other riders. I did set the Low Battery Protection at 41 volts and Current limits at 18. After reprogramming the bike is just fantastic to ride with the factory setting it was very jerky and kinda scary at some low speeds. At other times didn't even know that it was doing anything. Took the bike out to test the battery, run it down and see when it would cut off. Garmin said I did 72.4 miles with 1774ft of climbing at a moving speed average of 19.8. Near the end of the ride I was riding around 28-29 mph try to use up some battery. Around mile 69 the battery was reading 45 volts jumping down to 44.9. The little battery on the display beside the voltage was almost all black with just a little white showing. Then it shut off, the display went dark, everything off. Rode the next 3 miles back to the car without power. I'm very very pleased with Baffang kit and the battery never expected the speed (had it doing 38.4 on flat ground with 80% power) it has nor the range of the battery. Just curious why did the battery shut down at 45volts,was it the controller or does the battery have so type of protection? Thanks I have enjoyed reading everyone's post I'm new to the e-bike world.
Both the controller and battery have Low Voltage Cut Off. Depending on what each is set at will determine who will activate first. One way to know would be to do your test again and when it shuts down use a voltage meter to see if the battery still has output. Typically if the battery shuts down it would require a toggle of the switch, connection of the charger or possibly reset itself after it cools and settles at a slightly higher voltage. With all the different BMS's... It's hard to say for certain.
Enjoy the new ride!
 

AHicks

Well-Known Member
Region
USA
City
Snow Bird - Summer S.E. Michigan, Winter Gulf Coast North Central Fl.
Something else to consider is voltage "sag". The battery may read 45v, but if you give it a shot of full throttle at that voltage, it could easily sag down to the cut off voltage depending on how long you were using full power. A minute or 2 would do it....

That's why I charge at 46v. The idea of it cutting out while I'm crossing a busy road is not real appealing....
 

TLC

New Member
Region
USA
That would really be hard to do but I guess its not impossible. Would really have to be careful on long rides. Thanks and I see how thats the safest thing to do.
 

Gionnirocket

Well-Known Member
Region
USA
City
Y. O.
That would really be hard to do but I guess its not impossible. Would really have to be careful on long rides. Thanks and I see how thats the safest thing to do.
Well I wouldn't let it interfere with your enjoyment.
My rides are typically 20 - 30mi and I like to pedal as much as I can so it's not really a problem for me. But I wouldn't cut a ride short for battery sake.
 

AHicks

Well-Known Member
Region
USA
City
Snow Bird - Summer S.E. Michigan, Winter Gulf Coast North Central Fl.
Master Rocket has it exactly. I charge when the voltage gets down to 46v.

Not sure why it would be hard? My Ultra powered Rize fattie with 19.2ah battery has a range of 30 miles plus while riding in pretty hilly terrain with my 300lb but on it.

Are you saying you need more range than that for a single day of riding?
 

TLC

New Member
Region
USA
Most of our rides are between 50 and 65 miles, If 46volts is my limit that what I will have to live with. The only problem I think that might come is climbing and I might just have to work harder. I have read to charge the battery after every ride. Do you do different?
 

AHicks

Well-Known Member
Region
USA
City
Snow Bird - Summer S.E. Michigan, Winter Gulf Coast North Central Fl.
Most of our rides are between 50 and 65 miles, If 46volts is my limit that what I will have to live with. The only problem I think that might come is climbing and I might just have to work harder. I have read to charge the battery after every ride. Do you do different?
No, as a 300lb 70 year old, my rides are generally MUCH shorter! The maximum range for my butt is only about 20 miles, even when I stop every few miles to get the blood going. Been that way since I started riding again with my first e-bike back in 2015. Anyway, I am able to ride right from the house here, and I do that everyday, sometimes twice a day if it's nice and I have the time. My "average" ride is only about 5-6 miles. I do a full charge every time I charge (because the bike is never sitting more than a few hours), but I let the mileage accumalate until the battery gets down to 46v or so. Average mileage between charges depends on the bike and where I'm riding (hilly area in Florida or in Michigan without much in the way of hills). Rarely do I charge with less than 30 miles on the clock, or more than 40. That's pedaling in PAS 1 from the time I leave until returning. The wife, who rides with me most of the time, can double my mileage between charges, but she weighs less than half of what I weigh and often runs in PAS 0 on the level. This is us though.....

There's no hard and fast rule that says you MUST charge when the battery gets down to 46 volts. When running much below that though, realize that a wide open burst with a motor the size of yours can cause enough voltage sag to shut your power off. I use 46v as a target voltage. Where your target is is a call you'll need to make. I would only caution that running a battery in a low charge state frequently is hard on them.....

If I were planning rides in excess of 30-40 miles, safe bet I would leave on a trip like that only after a fresh full charge.
 
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Gionnirocket

Well-Known Member
Region
USA
City
Y. O.
Most of our rides are between 50 and 65 miles, If 46volts is my limit that what I will have to live with. The only problem I think that might come is climbing and I might just have to work harder. I have read to charge the battery after every ride. Do you do different?
If your typical rides are that long... Then by all means use it to the extent that you need to.
Keeping a battery between 40% - 80% is its sweet spot for cycle longevity... But if it interferes with what you want to do I wouldn't hesitate to use it to its full capacity.
Here's a good read to better explain the details. E-Bike Battery Guide
Now charge it up and go for a ride!
 
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TLC

New Member
Region
USA
Thanks for the input but I never know what ride I'm going on, fast, long, or how high. I will just charge my battery after every ride and if it goes bad I just will replace it.