Motor/Controller Upgrade (Armada Predator)

[dbossko]

Hello! New to post here but have been reading the forums for quite some time now. Last year I purchased a chinese electric motorcycle called the Armada Predator. It came stock with a 3000W hub motor and a 72V40ah lithium battery.

I felt I needed more power so I contacted QS motors and ordered a 6000W hub motor and a Kelly (KLS7275H) controller.

I contacted a local company nearby to perform the installation. They installed it although with one hiccup. When I go WOT the voltage dips drastically and the bike shuts down. We played with the controller settings and put one setting to 40 instead of 100 and that made it work although the acceleration didn't feel as zippy. This issue begins to happen again when my battery is at 50% or so.

Is it the battery thats causing it? The tech that was helping me says he suspects the battery or the bms?

Thanks!

http://www.sdpacific.ca/otherimages/Armada1.jpg
http://www.sdpacific.ca/otherimages/Armada2.jpg
http://www.sdpacific.ca/otherimages/Armada3.jpg

 

[brazilianboy]

Probably the battery is not up to the task. The voltage sag is so much that trip the bms. Which means the cells are not good enough to discharge as much current as demanded by the controller.

You best bet would be search for a local reliable battery builder on your area to build a high discharge battery for you.

I shall tell you in advance, in won't be cheap but if you don't it right, will worth every penny.

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[dbossko]

Thank you for the reply. What specifications should I be looking for specifically? The controllers specs states:

Motor Current Limit: 200A Continuous

If I get a battery with a higher AH will that help?

Thanks again!

 

[brazilianboy]

Oh boy. You are on for a ride. Are you good in math?! I hope you ready to learn a lot because if you don't understand, nothing will make sense.

All comes down to the cells specification on the battery pack. You will need a pack with cells capable of high discharge for the moment when the controller request to current, it can be supplied on accelerations. Also this pack needs to be very well built with thick wires to minimise resistance/heat/voltage sag. If using 21700 or 18650 cells needs to be very well spot welded and inspected to be sure everything is done properly.

More AH is always good but your space is limited so high discharge cells do the same job whilst the pack will be smaller because you will need less cells in parallel do supply the same of even more current. Because to achieve high discharge with regular cells you need more cells in parallel, making the pack bigger and heavier, so you will need more cells in parallel to compensate and so on...

To understand this concept, imagine you are with 12 friends pushing a piano upstairs, more people can push easier but they take a lot of space. Now imagine you have just 4 friends instead of 12 but they are body builders. They Can do the same job easier without taking so much space
Voltage is how fast they can push

Same with batteries.
More in Series = higher voltage
More in parallel = more current and range

High voltage = high speed
High discharge = more acceleration



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[E-HP]

Hello! New to post here but have been reading the forums for quite some time now. Last year I purchased a chinese electric motorcycle called the Armada Predator. It came stock with a 3000W hub motor and a 72V40ah lithium battery.

How much did they charge for the upgraded battery. Since the original motor was rated at 500W, 3000W peak, then the battery would only need to supply 7A continuous and 40A peak. Since the battery isn't described as using Sony/Panasonic/Samsung/LG, or any other quality cells, then it's likely made of generic Chinese cells, typically rated around 2500mAh.

That would make the pack 20S16P or so (40/2.5). If the generic cells are good for 5A, then that's 80A continuous, or good for 5.7kW when new. Your battery likely can't supply the continuous rating or the motor, and falls far short of the peak power.

 

[dbossko]

How much did they charge for the upgraded battery. Since the original motor was rated at 500W, 3000W peak, then the battery would only need to supply 7A continuous and 40A peak. Since the battery isn't described as using Sony/Panasonic/Samsung/LG, or any other quality cells, then it's likely made of generic Chinese cells, typically rated around 2500mAh.

It was suppose to be $2k extra for the lithium but they bought back the lead acids that were in there from the factory. So they ended up giving me the lithium for $1k.

That would make the pack 20S16P or so (40/2.5). If the generic cells are good for 5A, then that's 80A continuous, or good for 5.7kW when new. Your battery likely can't supply the continuous rating or the motor, and falls far short of the peak power.

When I was looking up my controller it said it was capable of 200A continuous. Does that mean I need to ensure the next battery is 200A continuous?

I think I found someone to custom make the battery for me. In your opinion, what should I request for them to do to (spec wise) to ensure I have no issues?

Thanks for everyones help btw!

 

[dbossko]

More AH is always good but your space is limited so high discharge cells do the same job whilst the pack will be smaller because you will need less cells in parallel do supply the same of even more current. Because to achieve high discharge with regular cells you need more cells in parallel, making the pack bigger and heavier, so you will need more cells in parallel to compensate and so on...

Thank you for the explanation. It actually helped quite a bit! I appreciate it.

 

[E-HP]

When I go WOT the voltage dips drastically and the bike shuts down.

What are the symptoms of shut down? Does all of the power go out (display and any lights shut off), or is there just no power to the motor? If everything goes out, then there still is a possibility that its the BMS and not the pack. I'd open up the pack to see what you have before just buying another battery. The number of cells and configuration, the BMS that's installed, plus anything printed on the cells would all be helpful info.

 

[brazilianboy]

More AH is always good but your space is limited so high discharge cells do the same job whilst the pack will be smaller because you will need less cells in parallel do supply the same of even more current. Because to achieve high discharge with regular cells you need more cells in parallel, making the pack bigger and heavier, so you will need more cells in parallel to compensate and so on...

Thank you for the explanation. It actually helped quite a bit! I appreciate it.

You are welcome. Rule of thumb is: Never trust on battery stats from Chinese vendors with a few exceptions.
This is not some xenophobic bs and I'm not hating on anybody, I buy from China all the time and I love it. Its just depends on what you buy...

Would be greay if you have bought this bike without battery and controller then do it yourself.
What you can do at this point is sell your battery if you want to invest on a new custom battery. Can you please try to find your bike controller and share the the model number or any information you can find about the controller plus photos?

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