New here: Questions on new Ebike.

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I'm new here and new to ebikes in general so please excuse me if my questions are frustrating to some of you :|

I built an Ebike and it has two 48v 10Ah in parallel @20Ah total and they are the EXACT same battery from Viset with BMS. The bike has a 350w 15a controller that's rated at 19v/30v low voltage protection and a 1000w rear hub motor. I am going for a 35a controller and expect to have a decent acceleration increase with a slight speed increase. It appears to me that my controller is the bottleneck here so I should expect to see at LEAST a slight increase in everything. At least that's what I am hoping for lol

Specs in a nutshell.
Battery: Viset 48v 10Ah with BMS. 30 amp max continuous. 60+10 amp max peak current each. I have two in parallel for 20Ah.
Motor: 1000w rear hub. No details.
Controller: 350w 15 amp with 19v/30v low voltage protection.

My two questions are.

1) Will I get any speed increase going from 15 to 35 amp controller? I do understand that controllers don't necessitate a speed increase but going from 15 to 35 is significant to running my 1000w motor to it's full potential. I feel that enough force of acceleration will impact my speed to a degree and not just on hills, but tagging my 180 pound weight around easier which would have to give me a speed increase in some way. Right?

2) I have two batteries in parallel and they work great. Each battery runs at 30 amp max continuous and 60+10 amp max peak current. I know running in parallel gives double the amp hour. However, what about running them in a series instead? Technically that should take my voltage from 48 to 92 and give me a nice boost that way. Does that mean I would only get 10Ah? I also heard you can run in both Parallel and Series. Does a series affect the amp max continuous? (If that makes sense hehe)

Interesting side note, I went from a 350w motor to a 1000w motor and I got an extra 5mph with the same batteries and 15a controller. My max speed with the 350w motor got me to 20mph. The 1000w motor got me to 25mph. I expect with the new 35a controller to give me at least 30mph.

 

[markz]

Speed is Volts
Increasing discharge amps increases total Watts which is to say Volts times Amps, and watts is good for going up hills faster, more torque but be careful that you dont go cooking your motor but I think you should be alright at 30-35A at 48V just dont stall or go to slow for to long, if you have thermal cut off even better then dont have to worry.

Series two batteries means you double the voltage and probably break your controller unless you have a 96V controller.

Ah is the distance you ride depending on if you pedal, your weight.....wh/distance [km.miles]

btw motors have a difference specification, kv or Turn Count, means more or less speed, so two exact same motors one with 3T means much faster per volt, vs 8T much slower per volt. Also the faster you go the more the battery depletes the less further you can go, other factors include the total weight, hills, wind, if you pedal or not
so you must compare apples to apples.

 

[E-HP]

I'm new here and new to ebikes in general so please excuse me if my questions are frustrating to some of you :|

I built an Ebike and it has two 48v 10Ah in parallel @20Ah total and they are the EXACT same battery from Viset with BMS. The bike has a 350w 15a controller that's rated at 19v/30v low voltage protection and a 1000w rear hub motor. I am going for a 35a controller and expect to have a decent acceleration increase with a slight speed increase. It appears to me that my controller is the bottleneck here so I should expect to see at LEAST a slight increase in everything. At least that's what I am hoping for lol

Specs in a nutshell.
Battery: Viset 48v 10Ah with BMS. 30 amp max continuous. 60+10 amp max peak current each. I have two in parallel for 20Ah.
Motor: 1000w rear hub. No details.
Controller: 350w 15 amp with 19v/30v low voltage protection.

My two questions are.

1) Will I get any speed increase going from 15 to 35 amp controller? I do understand that controllers don't necessitate a speed increase but going from 15 to 35 is significant to running my 1000w motor to it's full potential. I feel that enough force of acceleration will impact my speed to a degree and not just on hills, but tagging my 180 pound weight around easier which would have to give me a speed increase in some way. Right?

2) I have two batteries in parallel and they work great. Each battery runs at 30 amp max continuous and 60+10 amp max peak current. I know running in parallel gives double the amp hour. However, what about running them in a series instead? Technically that should take my voltage from 48 to 92 and give me a nice boost that way. Does that mean I would only get 10Ah? I also heard you can run in both Parallel and Series. Does a series affect the amp max continuous? (If that makes sense hehe)

Interesting side note, I went from a 350w motor to a 1000w motor and I got an extra 5mph with the same batteries and 15a controller. My max speed with the 350w motor got me to 20mph. The 1000w motor got me to 25mph. I expect with the new 35a controller to give me at least 30mph.

a) Since your current speed it 25mph, your top speed can be limited by voltage (back EMF) and/or wind drag. But, if your top speed were something like 20mph, then it's more likely that back EMF is limiting your speed.

Right now, your 350W controller isn't able to even provide 1000W to your motor. At 15A and 48V, that's just over 700W; I'd upgrade on that basis alone since your batteries can support a lot more.

Anyway, my guess is that you'll pick up a few or more mph going to 35A. Looking at what a typical 9C motor does with those parameters, here's how if might compare based on the Grin simulator. You didn't mention your tire size, so I just used 26".

https://ebikes.ca/tools/simulator.html?motor=M2705&batt=cust_48_0.05_20&cont=cust_15_40_0.03_V&hp=0&axis=mph&frame=mountain&autothrot=false&throt=100&grade=0&cont_b=cust_35_93_0.03_V&motor_b=M2705&batt_b=cust_48_0.05_20&hp_b=0&bopen=true

b) The problem with running 26S is that fully charged, it comes to 109.2V, The common capacitor voltage a lot of controller have are 100V, so good for 23S. There are fewer choices above 100V. The second problem is that most throttles are uncontrollable when your voltage is that high, so you need a programable controller or Cycle Analyst to control the throttle ramp to allow the bike to be rideable.

 

[Loginphp]

Thank you guys so much! As you can tell I have a lot to learn but I knew this was the spot to come. I am not educated on much of that you guys are telling me but I'll break down eqfh of your posts later and research it. In the meantime I have just couple more questions.

I think you should be alright at 30-35A at 48V just dont stall or go to slow for to long

Series two batteries means you double the voltage and probably break your controller unless you have a 96V controller.

1. What do you mean don't stall or go slow too long? How does that affect everything? So it's better that im using the power more often?

2. So youre saying it's ok to go series only if my controller can handle it? I would think 96v would pack a bigger boost than 48v but that would cut my Ah back in half wouldn't it? I heard you can do both at the same time but I'm not sure.

a) Since your current speed it 25mph, your top speed can be limited by voltage (back EMF) and/or wind drag. But, if your top speed were something like 20mph, then it's more likely that back EMF is limiting your speed.

Right now, your 350W controller isn't able to even provide 1000W to your motor. At 15A and 48V, that's just over 700W; I'd upgrade on that basis alone since your batteries can support a lot more.


b) The problem with running 26S is that fully charged, it comes to 109.2V, The common capacitor voltage a lot of controller have are 100V, so good for 23S. There are fewer choices above 100V. The second problem is that most throttles are uncontrollable when your voltage is that high, so you need a programable controller or Cycle Analyst to control the throttle ramp to allow the bike to be rideable.

They are 12" tires. I already understand that smaller tires will struggle more to maintain top speed and eat up battery faster but give a nice acceleration boost. That's about all im aware of.

Like I mentioned I will need to research the information in your post so I won't boggle you down with questions but I do have a couple to ask.

1. What is EMF exactly and how will I be able to tell what mine is?

2. The newer controller doesn't say much what wattage it is, but I believe it's up to 3000w. It just says 250-3000w and is suitable for 1500w motors. So yeah based on what you can see I should get at least a few more mph.

Running my batteries in a series sounds interesting but apparently there are too many repercussions so I'll just keep them in parallel.



Interesting side note. When I use a single 10Ah 48v battery my bike runs great and all, but I notice the acceleration and even the speed are slightly more with two in parallel. Is that normal? I feel like that may be because of the voltage is more consistent then using one battery. I get nearly a whole volt more at full load using two batteries over one battery. I didn't know if that has something to do with an advantage of parallel vs one battery. But that makes me wonder...what would a single 20Ah 48v batter be like vs my two 10Ah 48v batteries in parallel? Who knows. Might there be a fluctuation in voltage somehow between the two differences?

Thank you guys so much! I'll be back here if I have any more questions and I'll be researching everything here.

 

[markz]

1. What do you mean don't stall or go slow too long? How does that affect everything? So it's better that im using the power more often?
Stall is going full throttle yet you barely move, you cook the motor

2. So youre saying it's ok to go series only if my controller can handle it? I would think 96v would pack a bigger boost than 48v but that would cut my Ah back in half wouldn't it? I heard you can do both at the same time but I'm not sure.
Increasing volts to 96V will increase/double total watts and increase/double speed dramatically if you series your batteries. There is no need to go super duper fast as we diy ebikers are responsible riders of electric bicycles who are courteous and ride at reasonable speeds.

Interesting side note. When I use a single 10Ah 48v battery my bike runs great and all, but I notice the acceleration and even the speed are slightly more with two in parallel. Is that normal?
Voltage sag on the batteries when using one, much stronger and less voltage sag doubling them up in parallel for Ah.

Don't get to deep into knowing to much, just get the basics down and understand the fundelmentals and don't buy unnecessary stuff like what I did when I bought lipo batteries and cheesy wimpy 50W charger, or get a wimpy bike just to spend more money to get a not so wimpy bike for all those reading contimplating what to do but for you you already have a riding ebike so just enjoy. Get the parallel battery, series thing down pat and dont get sucked into myths.

 

[E-HP]

They are 12" tires. I already understand that smaller tires will struggle more to maintain top speed and eat up battery faster but give a nice acceleration boost. That's about all im aware of.

You may not see a gain in speed. You'll get faster acceleration up the the top speed though.

https://ebikes.ca/tools/simulator.html?motor=M2705&batt=cust_48_0.05_20&cont=cust_15_40_0.03_V&hp=0&axis=mph&frame=mountain&autothrot=false&throt=100&grade=0&cont_b=cust_35_93_0.03_V&motor_b=M2705&batt_b=cust_48_0.05_20&hp_b=0&bopen=true&wheel=12i&wheel_b=12i&kv=16&kv_b=16

 

[Loginphp]

They are 12" tires. I already understand that smaller tires will struggle more to maintain top speed and eat up battery faster but give a nice acceleration boost. That's about all im aware of.

You may not see a gain in speed. You'll get faster acceleration up the the top speed though.

https://ebikes.ca/tools/simulator.html?motor=M2705&batt=cust_48_0.05_20&cont=cust_15_40_0.03_V&hp=0&axis=mph&frame=mountain&autothrot=false&throt=100&grade=0&cont_b=cust_35_93_0.03_V&motor_b=M2705&batt_b=cust_48_0.05_20&hp_b=0&bopen=true&wheel=12i&wheel_b=12i&kv=16&kv_b=16

I just installed the new controller so I want to compare the accuracy of the simulator to my experience. I use my phone GPS to monitor speed accurately. First of all, fun!! I feel like for me personally I don't necessarily need to go any faster than I do now.

I got a major acceleration boost! 15a>35a. I tested acceleration mainly going up and down the length of one block on an evenly straight path.

With a 15amp equipped I hit 25mph max by the time I get to the end of the block. That's fast, but it takes the whole block just to hit that speed. So my acceleration goes get me to max speed but it takes the length of the entire block just to get my max.

With a 35amp equipped I hit 32mph, not even knowing if thats the max , by the time I get to the end of the block. I hit 25mph in about 7 seconds or so MUCH quicker than before, long before I even get to the end of the block. I barely even get moving and I hit 25 now on the fly. So that is a massive gain in acceleration! Also 7mph faster. I'm not sure why I got a speed boost but I just believe that's due to the extra momentum and force the 35amp gives me. I can imagine how much faster I would go with larger tires.

It sure was quite fun! But there was something funny about doing speed tests...I still don't know for sure what my max speed is because I got TOO SCARED hitting 30 on 12 inch tires without a helmet and super cheap kids tires. My back tire popped the other day and I used welding glue and gorilla tape to patch it up. These factors make me feel extremely unsafe to be able to push the bike to its limits on a much longer stretch. I will try that another day when I'm not scared and have more expensive tires.

The simulator had my 15amp max speed correct but I don't really know how to explain the speed gain I received with 35amp. Could it be the parallel connection? Went from 23-25 to 29-32. I love how it not only goes faster but it goes faster MUCH MUCH quicker and WAY more often making the bike truly feel like it's got an excellent speed AND acceleration boost.

Thanks to everyone here who have taught me some things and lead me in the right direction. The simulator is amazing and has helped me a lot.

 

[E-HP]

The simulator had my 15amp max speed correct but I don't really know how to explain the speed gain I received with 35amp. Could it be the parallel connection? Went from 23-25 to 29-32. I love how it not only goes faster but it goes faster MUCH MUCH quicker and WAY more often making the bike truly feel like it's got an excellent speed AND acceleration boost.

Sounds like it worked out well.

The simulator was only an example using a motor from the drop down, and only showing the relationship between speed, load, and current/power. Couldn't model your motor, since you said "Motor: 1000w rear hub. No details."

 

[Loginphp]

The simulator had my 15amp max speed correct but I don't really know how to explain the speed gain I received with 35amp. Could it be the parallel connection? Went from 23-25 to 29-32. I love how it not only goes faster but it goes faster MUCH MUCH quicker and WAY more often making the bike truly feel like it's got an excellent speed AND acceleration boost.

Sounds like it worked out well.

The simulator was only an example using a motor from the drop down, and only showing the relationship between speed, load, and current/power. Couldn't model your motor, since you said "Motor: 1000w rear hub. No details."

True! Thank you very much I'll be coming back here regularly from now on.

 

[ZeroEm]

I think he is hooked :thumb: . eBikes rule.