52v triangle battery shutting down once hits 53v

[Marc Gore]

I have a 48 v 1000 w rear wheel kit on a mountain bike . I built a triangle 52 v battery from the book sold on you tube was told most 48 v bike kits can take the 52 v battery just increases power and longevity but the battery fully charged is
58.6 v and the bike runs great once the battery reaches 53 v the bike shuts down around 5,6 miles and the controller gets fairly warm is there a setting I am missing on the LCD screen or something else I will attach pics of battery bike and kit I used . Any help would be GREAT
Thanks
Marc

 

[Sierratim]

The sepc sheet references a 'ControllerBag'. Do you any specs on the controller itself?

Is this throttle controlled?

You say the controller gets "fairly warm" within the first 5 - 6 miles. Can you comfortably leave your hand on the controller, or no? What are these riding conditions like, i.e. how much power are you drawing?

 

[Marc Gore]

you can leave your hand on it but still pretty warm the controller is 48 v controller that came with the kit I will attach wiring pic not sure about other specs it is a twist throttle

 

[Marc Gore]

would the BMS shut it down I put an on off switch on the Neg of the battery and when I turn it off then back on it will start back up and run for just a min or 2 I use all new batteries and was very careful pairing groups by the capacity voltage

 

[Marc Gore]

not sure what the power capacity usage is i am a big guy 300# am I to big for this motor trying to run around 20 MPH on flat surface but a few hills I am if Florida pretty flat

 

[Sierratim]

would the BMS shut it down I put an on off switch on the Neg of the battery and when I turn it off then back on it will start back up and run for just a min or 2 I use all new batteries and was very careful pairing groups by the capacity voltage

The warm controller concerns me, i.e. overheating in just 5-6 miles due to higher than rated current being driven by the higher voltage but I think it's more likely the BMS shutting that pack down. As you probably know the BMS monitors cell voltages to prevent over discharging any one cell. When any cell voltage gets to the minimum set point, the BMS shuts the pack off. Turing the battery off resets the BMS. By then the low voltage cell could have recovered allowing the pack to power the motor again.

I'd suggest opening up the pack and testing the cell voltages under load. You may be able to find a weak cell and replace it.

 

[Marc Gore]

Not sure I know how to test voltage under load is there a You tube video showing how maybe a larger BMS this is a 42 v - 50.2 v BMS I have a 42 - 58 V bms on the way but taking forever coming from India Is there a local or US place to get some of these items i need I E. different controller or BMS By the way thank you so much for your help

 

[rich c]

More likely a problem for the controller than the motor for over volting. Did you enter a different voltage while programming the controller? Or does it think it is seeing 48v?

 

[Marc Gore]

I tried changing it to 60 v but it seemed to slow the bike way down it I have options on the LCD screen sates 36 v, 48 v, 60 v would not go over 8 MPH and was week and would only show 1 spot on the battery charge display on the screen I did switch it back to show 48 v

 

[Sierratim]

Grin Technology out of British Columbia is a great ebike component supplier. They may have a higher voltage rated BMS in stock, but of course this won't resolve a weak cell issue.

I Googled for videos using "testing lithium battery pack cell voltage under load". A couple of likely ones showed up. I'd start with this one;

. The basic concept is to use light bulbs to load the battery pack. In years past when I was doing DYI ebikes I wired up a bunch of light sockets with incandescent bulbs to load test my batteries. Once you do this you can measure the cell voltages while the battery is at various loads. The load is adjusted by adding more bulbs and/or chaging the bulb wattage. Worked well. Cost ~$10 for the light sockets. I had a bunch of incandescent bulbs left over from a flourescent bulb swap out.

This video talks to testing in sets, but the concept is the same;

. There are more, but this should get you started.

If you find a weak cell, replace it, or wire it out of your pack to back to a standard 48V, 13 cell pack.

If you don't find a weak cell, I would suspect the controller. You could upgrade to a higher rated model, or rewire your pack to a standard 48V setup.

 

[harryS]

58.6 v and the bike runs great once the battery reaches 53 v the bike shuts down around 5,6 miles and the controller gets fairly warm is there a setting I am missing on the LCD screen or something else I will attach pics of battery bike and kit I used . Any help would be GREAT

Home made battery? What is the quality of your cells? Are they all the same? Who made them? How many AH is the cell rating? DId you solder or spot weld?

To me, this sounds like voltage sag shutting off the controller. With a heavy current load pulled by a Voilamart motor, and low cost cells, it's possible the working voltage drops below the 40-41 volt minimum programed into the Voilamart, even at a nominal level of 52V. It could also be voltage sag shutting off the BMS. It happens so fast, even if you have a voltage level on your display, it won't show,

Buy a Tenergy (or a cheaper copy) wattmeter for about $12-20. It gives all kinds of useful info, like the minimum voltage, maximum current, as well as instantaneous values of current, watts, AH, and voltage. It will record the minimum voltage seen during shutdown, unless your battery BMS is shutting down. If you lose power, you lose all the readings. The wattmeter can be powered off a 9 volt battery to save the info in that case. Good luck,

 

[Marc Gore]

a lot of info Thank you all. I do not see a setting for lower end voltage . I used new Samsung batteries all tested and within .1 ma of each other I have the same tester as above blue one and had to test each battery 1 at a time,took forever.I took it for a ride again yesterday and at almost 7 miles it powered down the battery was 58.8 V when i started ran like a champ and when it shut down was at 52.6 v just seems weird it shuts down at the end something has to be telling it to shut down I have the SW 900 LCD screen that has all the settings I will check those copy down whats on it and come back and ask again I think its the controller or BMS

 

[harryS]

My SW900 has a P03 voltage setting for 24, 36, 48, and 72 volts. If I it set for 72, it will shut down around 52V.

 

[Marc Gore]

Sierratim I did watch both of those videos the bottom one is how I learned to discharge the battery to get the capacity but on the 1st one the light bulb lights up when good does it not light up at all ,or flicker, or what when bad ?

 

[Sierratim]

Sierratim I did watch both of those videos the bottom one is how I learned to discharge the battery to get the capacity but on the 1st one the light bulb lights up when good does it not light up at all ,or flicker, or what when bad ?

The bulb goes out when the BMS cuts the battery output. Otherwise, it's hard to notice a drop in brightness as the battery voltage slowly drops. The idea here is to use higher load bulbs (incandescents) to load the battery until it cuts out then check cell voltages to see if any are appreciably below the others. If so, that's the likely issue. If not, then perhaps the BMS.

I used up to a dozen 60-100W bulbs to get a battery load that simulated local riding conditions. My 48V battery was rated at 20Ahr. I was going for at least a 10A load.

 

[Marc Gore]

Mine goes to 60 on the PO3 setting i keep it @ 48 v setting correct ?but I sure have a few things to check out

 

[harryS]

You might check the voltages on all 14 series groups unless you have one of them fancy BMS that reports those voltages via bluetooth. Could be one set of cells that didn't get charged.

 

[Marc Gore]

no blue tooth but just built the battery a week ago should be fine but I will check that again as well Thanks

 

[harryS]

This isn't a Vruzend type battery is it? The kind where you put the cells into holders and use metalstrips screwed into plastic for contacts?

 

[Marc Gore]

yes it is red and blue just like picture above i do have a different BMS 14 s 45 A 48v- 50.2v