FlexiBMS Lite - Flexible Configuration BMS w/ CAN-bus

[rusins]

@SimosMCmuffin

I informed that I want and intend the FW to be open-source

Love that!

@SimosMCmuffin

“FlexiBMS Lite 18S” (name likely final) prototype board (6S-18S Lite variant)

Assuming it’s similar in size to the current 12s version, I NEED that

[Jamie42]

@janpom

PayPal rant. So, PayPal is kind of expensive. They charge me around 5.5% on transaction fees on average. 5.5% may not seem a lot at first sight. Think about this though:

Say that you’re a merchant operating with a 30% margin. You get stuff for 100 EUR and re-sell at 130 EUR. But of course you have to ship it. Say the shipping cost is 15 EUR and you’re not adding any margin on top of it. And you’re a VAT payer so you need to add the 21% VAT. At the end, you charge your customer (130 + 15) * 1.21 = 174.45 EUR.

You made 30 EUR on the sale. Or did you? Well, here’s the thing, the 5.5% that PayPal charges you is not calculated from the 30 EUR you have made (or more specifically, you wish you have made). It’s calculated from what you have charged. So it’s 174.45 * 0.055 = 9.65 EUR. So it has basically eaten a third of your earnings. In my country, that would be two times more than the income tax.

So yeah, 5.5% is quite a big deal, especially for some. Of course, this was just an example. I’m not trying to imply this is my situation. Just making the point that 5.5% is by far not what you could call negligible.

Now, my plan for the new e-shop was to accept credit card and PayPal payments and charge the transaction fee to the customer. That’s simply because I like to be transparent about things. I don’t want to pretend that it doesn’t matter how you pay. I currently get charged 2.3% for a card payments (it should converge to around 1.5% pretty quickly; fee is getting lower with more sales) and 5.5% for PayPal. It just seems fair to charge the customer less if they pay with the cheaper payment method.

Well, guess what. PayPal forbids you to do that. You’ll find this in their license agreement:

Of course they don’t want you to do that. They don’t want people to realize how much more expensive they actually are compared to other payment methods.

This is just ridiculous. And of course, you can’t not accept PayPal because for some reason everybody wants to pay by PayPal. People are just used to it or some may not have other options. So if you drop PayPal from your accepted payment method you loose a ton of sales.

Anyway, I’m increasing all my e-shop prices by 5.5%. If you can pay by a credit card, I invite you to do it. 4% discount will be applied at checkout upon selecting the credit card payment method.

@SimosMCmuffin

Paypal
Unfortunately paying with a credit/debit card via Paytrail doesn’t seem work for everybody, so to add another payment method, which is internationally used, should allow everyone to make their payments. They do have slightly higher fees than Paytrail, so there will be a +2% fee added when paying via Paypal.

Just a heads up, it seems like PayPal doesn’t allow you to surcharge your customers for using it as a payment method.

[Skyart]

Congratulations Simo! looking forward to all your development work!

[ShutterShock]

@Jamie42

doesn’t allow you to surcharge

Yeah the easiest solution is making it cost a little bit more

[b264]

@Jamie42

Just a heads up, it seems like PayPal doesn’t allow you to surcharge your customers for using it as a payment method.

That’s easy, just raise prices and offer a discount for not using PayPal / ServiceName

[janpom]

Right. That’s what I did. The problem is that all prices then look more expensive than they actually are (if you don’t use PayPal). That kinda sucks since most people don’t decide about purchasing rationally. For some, $99.99 may be an acceptable price while $100 would be too expensive.

[TarzanHBK]

Nice one! We are going to need about 10 more Flexi BMS for an upcoming project soon - i´ll let you know in a few weeks

[SimosMCmuffin]

@rusins

Assuming it’s similar in size to the current 12s version, I NEED that

It’s gonna get longer, as I need to fit 6 more balance/bleed circuits + depending on if I need to go parallel mosfets for the (at least) 10 Amp charging current capability, as the higher voltage mosfets are usually higher Rds(on) in the same package size. It might also slightly widen to accommodate the square form-factor battery stack monitor IC (LTC6813), unless I do some tricks with the connector layout. Most likely I’ll be able to fit a dedicated connector to the NTC-temperature sensor with the added length.
Otherwise I want to keep it HW feature wise pretty close to the Lite (maybe re-name it to “FlexiBMS Lite 12S” for clarity/distinction between the two designs) apart from supporting up to 18S packs, so the FW stays easily compatible between them and not to divide/fraction the FW development.

@b264

That’s easy, just raise prices and offer a discount for not using PayPal / ServiceName

@janpom

Right. That’s what I did. The problem is that all prices then look more expensive than they actually are (if you don’t use PayPal). That kinda sucks since most people don’t decide about purchasing rationally. For some, $99.99 may be an acceptable price while $100 would be too expensive.

That’s what I thought of as well.

@TarzanHBK

Nice one! We are going to need about 10 more Flexi BMS for an upcoming project soon - i´ll let you know in a few weeks

Cheers.

[Halbj613]

personally i would prefer paying 99$ + a 5$ discount then just 94$ it feels good getting a discount

[NuRxG]

@SimosMCmuffin

“FlexiBMS Lite 18S” (name likely final) prototype board (6S-18S Lite variant)

20 or 24s please!

[Slightly_Mad]

@SimosMCmuffin

Paypal

Awesome
That’s the only reason why I didn’t bought FlexiBMS - no PayPal
Btw, I’ve sent you an email but got no answer (if a regular bank transfer is possible instead of MasterCard/Visa credit cards)

[edoardoconti]

My unit is finally here. Can’t wait to try it! *but I have to because of lot of stuff to study*

[edoardoconti]

Hello, I integrated the FlexiBMS Lite in my e-skate. It seems to work fine as far as the LED and serial communication functions. (wiring)

Now, I’ve also a Metr Pro installed and I was expecting to check the single cells voltage and others parameters as real time charging data. Is it possibile?

For reference, this type of integration:

[filipandre]

How do i get my hands on one of these? (12s)

[Acido]

https://finnkotronics.mycashflow.fi/product/1/flexibms-lite

Links a bit hidden in so many posts @filipandre

[PixelatedPolyeurthan]

@Acido

FlexiBMS Lite | FinnkoTronics Store

@SimosMCmuffin you should add your website link in your Bio

[filipandre]

So as I understand this, I can hook it up to my Davega X and have it show the cell voltages and more? @janpom

[Mainflow]

FlexiBMS has CANBUS. Hook it up to the vesc.

[filipandre]

But the vesc dont have a screen xD

[Mainflow]

The Davega X will notice this. Somewhere in the settings… (forgot about it)