Warrior trike- 1st build

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Apr 26, 2021
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Some stuff I ran into in regards to Lifepo4 batteries.



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Found these for charging a Lifepo4 battery pack.

If I've gathered everything right the process is:

Step 1: 1st stage constant current until it hits 43.8v

Step 2: Flip to 2nd stage of constant voltage until it hits 50.53A (95% state of charge)


Option 1. 43.8V @ 40A. Costs about $400




Option 2. 43.8v @ 4A. Costs about $40.


****

Ended up picking up this Suntour pro-compe 5 speed 14-34T freewheel.


Should be here in a few days.

Have to pick up a 2 prong tool for it.
 
Last edited:
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Apr 26, 2021
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103
These are just some notes for playing tetris with the battery design.

A 12s14p battery is 44A @ 53.19A

A 3s2p battery pack is 11V @ 7.6A

28 3s2p battery packs can be arranged as:

4 groups of 7 3s2p packs wired in parallel: Each group is 11V @ 53.19A

Wire those 4 groups in series: 44V @ 53.19A
 
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Apr 26, 2021
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Built the rear wheel today.

Don't have a way to true it since the stand I'm building isn't dialed in.

Going to drop off all 3 wheels at my local bike shop tomorrow to have them do it for me.

When that's done I should be able to dial in the stand using one of the wheels.
 
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As I look ad the price, I would go for option 2.
4a charging is fast enough to charge your battery.
I put my battery on the charger over night and it is ready the next day.
It takes 7 to 8 hours, depending the battery.
With both I get a good range, so I don't need fast charging.
I think that you can better get 2 batteries with the 4a charger.

I use the same brand sprockets. They do good.
I prefer 11 as smallest, but that is because my cadens is low.
I have one that is like that. So small steps in between and one that is more a mountain bike sproket.

I borrowed the tool, but I now also nought it. Thus way I can sap it out myself and repair more by myself.
 
Joined
Apr 26, 2021
Messages
103
As I look ad the price, I would go for option 2.
4a charging is fast enough to charge your battery.
I put my battery on the charger over night and it is ready the next day.
It takes 7 to 8 hours, depending the battery.
With both I get a good range, so I don't need fast charging.
I think that you can better get 2 batteries with the 4a charger.

I was thinking the same thing about the charger.

Don't think I can get away with splitting it into 2 batteries.

Specs for operating the motor: 36-72V @ 50A continuous.


I use the same brand sprockets. They do good.
I prefer 11 as smallest, but that is because my cadens is low.
I have one that is like that. So small steps in between and one that is more a mountain bike sproket.

I borrowed the tool, but I now also nought it. Thus way I can sap it out myself and repair more by myself.
Never used SunTour before, but I'd heard good things.

Sounds similar to why I went with one that's 14-34T.
 
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Apr 26, 2021
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The more I think about it and try to wrap my head around how to build the battery.... The less confident I feel in being able to do this without having to redesign the bike build.
 
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Apr 26, 2021
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You can ad battery mounts behind the seat.
Yep. I was fixated on attaching to the seat tube. Woke up today with an general idea of how it could work by utizing the back of the seat.

I'll worry about that when it comes to building a seat.
 
Joined
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On a warrior type design some bracing of the rear end is going to be essential given heavy batteries and a powerful motor are all acting on that weak point behind the seat.
 
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On a warrior type design some bracing of the rear end is going to be essential given heavy batteries and a powerful motor are all acting on that weak point behind the seat.
Definitely. Will be making something sturdier than a wooden seat to mount them to.
 
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Definitely. Will be making something sturdier than a wooden seat to mount them to.
You do realise he is not talking about the seat but the lack of triangulation at the rear ?

Covered in this recent thread :- frame broke persevere picture turns up eventually :whistle:

Paul
 
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Always a win when you make something do more than one job. That area is known to fail without battery weight or 1500W trying to bend it though how much of that is design and how much is poor welding is certainly anyone's guess.
 
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Always a win when you make something do more than one job. That area is known to fail without battery weight or 1500W trying to bend it though how much of that is design and how much is poor welding is certainly anyone's guess.
Thanks for the heads up.
 
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Apr 26, 2021
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103
SunTour freewheel showed up today.

Installed it. Trued and dished the rear wheel.


Stoked to get back to the frame.

Also the second shipment of batteries showed up.
 
Joined
Apr 26, 2021
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103
Had a couple jack stands show up. As well as the BMS and other miscellaneous stuff.

Loving Aliexpress... the brake calipers I ordered back in april must've vanished in the Bermuda triangle.

Worst case I'll pickup some avid bb7's off eBay.

Also gotta look into nickel strip thickness for the batteries I'll be building.
 
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