DC to DC step up Converters

Using Arduino General Electronics
#1

Hello!

I have kit that I installed on my 700c road bike. It's marked as 350watt which is meaningless, but I was told by the store due to law's here in Canada there is a top speed limit.

So as of now I have two battery packs, one is 10s2p from Hoover board 4A output 42v fully charged and an Xt60 connector, 36 nominal.

One quick question, what makes xt90 connectors anti spark? Cause I'm using 12awg wire on xt60s I did myself besides the single xt30 from a battery pack

The controller I have had one plug with I think 9 or 7 pins going from motor on front wheel to the controller.

I have a DC DC step down to 12v for the headlights, but I also took apart an old scooter got a 36v headlight (and horn combo) so must have a built in converter inside that. But the pack itself is really long and looks like it's 10s3p output 6A.

I have a lot of Samsung 18650 13s and 10s new BMS boards
I also have 2 5A DC step up but the best boards I have for stepping up are 2x 10A 500w adjustable voltage and current, I used JB weld to stick it to an aluminum heatsync and installed a fan. I also have a 400w step up with heatsync

I'm wondering how to do 2 different things, until I get my spot welder a better power supply and pure nickle strips instead of the nickle plated I have at the moment, I was gonna remove BMS on the 10s2p and add a 13s with more of the same mah cells I also v can't find a definite answer I know mah has to match as well as same cells in pack, but the discharge rate..... What if the cells are same brand same capacity, just one has a couple A higher max discharge rate than the others, will the BMS work and balance as long as they are the same mah cells.

So back to the main issue, is told once to hook up the step ups together, how will I set the current using that little knob. Going from 42v/36 to a 48v controller that can handle higher current.

Is there any way I can do all of this... What are my options.

With the step ups, the input current, does that get boosted as well, I only have one multimeter so I can't use it as voltmeter and ammeter at same time. I need to know how safely i can do this, but in the mean time, is there a way to join both packs I have in parallel.

What do I do? Suggestions?

#2

Ask on an E-Bike forum? There's nothing in this about Arduino.

Just one thing - if you could boost voltage and not have less current, you would have a perpetual motion machine because it would double the power. You could then feed back 50% of the power to the input, take away 50% as free energy.

Sadly, you can't.

#3

At first I was using Arduino Uno 3 to do a lot of this i understand what you mean I was thinking where ebike motors are BLDC and use tri delta in pulses I was hoping someone could point me in a decent place to learn

#4

It's highly specialized. I have seen some Ebike postings here, but there aren't very many people here that do that stuff. I think the thread will fall off the page before you get a real answer, it's not kosher to bump it. Sounds interesting anyway, good luck but stay safe.

#5

No. When you boost the voltage you lose current by the same degree. If, for example, you have a 12V battery and a 12-to-24V boost converter that you want to get 240W out of (10A*24V) you have to get a little more than 240W (20A@12V) out of the battery. Figure a 10% loss so you are drawing 22A (264W@12V) from the battery to get 10A (240W@24V) on the output side.

#6

Well, yes, the input current actually does get "boosted" - it is increased over the output current by the extent you increase the voltage and some more to account for the inevitable losses in the DC-DC converter

#7

This is a forum for Arduino users, you stand a far better chance of getting good answers on a eBike topic in an eBike forum such as;

https://endless-sphere.com/forums/

#8

You certainly aren't going to get useful feedback if you neglect to provide links to the datasheets/product pages for all the numerous bits of hardware you refer to - most of us have no idea at all what a "Hoover board 4A" is, for instance, or "xt90" and certainly aren't going to start researching it if you can't be bothered to provide links. We aren't paid to do this! Sorry, but that's the deal.