slow ebike... 80 volts ebike going 30mph? why so slow

hello... I bought a 48v / 72 volt controller from china... link to controller http://ebay.to/2Jl7HS4

I have a hub motor wheel, those 1000 watt 48 v wheel kits...

I have a lifepo4 battery a123 cells from batteryhookup i bought and they are 2 x 12 series = 24 series. I had them at 79 volts or 3.3 volts per cell and took the ebike out for a spin... The problem is it only went 30mph...

I dont understand as like i used to run a 48 volt / 54v full charge with this ebike before and it went 30mph... Shoudlnt it go faster now with the higher voltage...

I am curious maybe like at 3.3 volts, the lifepo4 a123 cells are empty? maybe one of the phase wires is lose so its only running 2 out of the 3 phases? I have this shitty wire crimper and its possible that some of the crimps from the phase wire to controller are lose or not that good. thoughts...

I am now going to charge the 2 banks to 84 volts and do another test... See if it goes faster. i'll let you know...

here are the spec sheets... https://www.buya123products.com/uploads/vipcase/844c1bd8bdd1190ebb364d572bc1e6e7.pdf


ebike pic... 2 banks of 12 series 8 parrell lifepo4. So a combined ebike system is 24 series 8 parell.

Is it possible that the throttle is not that good and sending a low voltage signal... its a 48 volt 3 wire throttle... also in addition to the red green black for the throttle, i have a blue brown and black low speed high speed medium speed connector, which maybe i need to use because currently its not plugged into anything.

What are your suggestions cause these a123 cells have like a 10 C rating on them...

It says in the advert of the link you posted that the controller has "three speed reversing" so it seems to have a 3-speed switch that needs to be installed. If you don't have such a switch installed the controller might be in "1st" (low) speed and you need to connect a compatible 3-speed switch to be able to choose 2nd (medium) and 3rd (top) speed. ask the seller of the controller which switch is needed for that controller. See the last picture in the link of the controller you posted:



The top and bottom connectors on the right side of the photo seem to be for switching the different speeds.
If a generic "3-speed switch" can be used then look at this one:
https://www.ebay.com/itm/22mm-3-Spe...861957?hash=item5b84ab97c5:g:50UAAOSwJ7RYV9wZ

Good luck.

..if slow co is not right on the money, then..

What's your voltage and amperage at cruise?
Also what is your no-load amperage ( wheel spinning in the air at full throttle )

You can find this out using a cycle analyst, watt meter, or any other device that is capable
This information will help rule out battery/current limit/a bad 3 phase connection combination.
..otherwise, prepare for random guesses.

This controller has a learning jumper wire, so its unlikely you are running in the wrong phase combination.

One thing is possible, you could have a connection that is connected, but so shitty it won't let full current flow. This could be on a phase wire, battery wire, or throttle wire.

Most likely though, its the three speed switch is defaulting to middle speed, which used to be typical.

The last possibility is that your batteries are turds, and under full 40 amps or so load, only put out about 50v, which would result in 30 mph. What is your voltage as you run 30 mph?

It's a guess, but I think the three speed one is the "dial three speed gear" plug. I've never seen a three speed selector that didn't have three wires.
For testing, you can just push a bent over paper clip into the center, and one of the two outer holes, then hold the wheel in the air and test it. One way should make the wheel spin noticably faster. Taking it back out defaults to medium speed.
FYI, pretty much all throttles use the same signal voltage (about 5v). Usually when they have a label like 48v, it's just what the LED battery indicator is calibrated for.

I run on high power all the time, so never bothered with a switch, but just use the paper clip. I used to worry about it more with police, so I figured if I ever got pulled over for speeding I could pull the clip and hide it. Luckily it never came to that...

bike4life said:

hello... I bought a 48v / 72 volt controller from china... link to controller http://ebay.to/2Jl7HS4

Click to expand...

Damn, can you make a side profile pic for that bike?