Complete Hobby King Lipo Protection Kit

[zukster]

That said - it would be pretty easy too defeat the latching aspect of breaker so that it just comes back on when the HVC condition clears if you want.... By shorting a pin you can set it up so that the LVC opto just shorts out the zener diode that holds up the gate voltage for the fet. Currently, the circuit actually opens a relay to latch the condition - but that does not have to happen.

You mean so you don't have to hit the reset button?

[atom1025]

Thanks Methods for the quick service, prompt response times, great advice and most of all thanks for going out of your way to make these available to us meatheads.

Everything is hooked up and running great!

Adam

PS Yes I paralleled the main leads.

[jonescg]

btw: How are you soldering those big copper blocks without overheating the cell tabs? You getting any puffing?
-methods

With two 80 W red-hot soldering irons dumping heat into the block and having lots of pressure from above to ensure a good connection is made. Then when it's settled I dab a sponge in ice water onto the copper to take the last of the back heat out. My pre-build thread has some video. In my opinion, this is the only way to draw high currents from LiPo. When you think about it - the tab is the bit that gets hot under high discharge. Where can that heat get sunk to? Without a good lump of copper, that heat will go straight back into the cell, which is not good. Also, since this will be sealed in a box, it won't get a chance to cool down. So over-specing is the only way to ensure nothing gets hot.

No puffing, no changes in performance to date (I haven't done heavy discharge testing yet - a 10 kW kettle is hard to make you know!) but a dead short across a 1s3p setup has no difficulty drawing 350 amps, and everything is still ice cold.

[jonescg]

OK three last questions before I part with my money (>$50 x 36 = $1800 )

1.
Is it possible to mix and match 6s, 5s and 4s units? Remember, I'm not doing any of that parallel harness crap. I have 6 blocks of 13s and 6 blocks of 15s. The 3 of the 5s guys would work fine for the 15s blocks, but I would need to use some combination of 5s units and a 4s for the other blocks.

2.
Why are there 7 wire pigtails being used to daisychain the boards together? If the boards are to be joined in series, wouldn't you just need one loop of a single strand? I'm not getting this bit.

3.
I don't want a throttle retard (I'm already one of them). I want it to simply sound a buzzer or illuminate an LED. Can this be done?

Oh, why not, I'll throw another question in while I'm at it If I pay you and your lackey enough, will you do a run of 13s and 15s boards?

[methods]

Yes - when a cell is below 3.0V it will cut your discharge current by opening the fet. When the cell floats back up, it will allow you to go again. No latching.

-methods

That said - it would be pretty easy too defeat the latching aspect of breaker so that it just comes back on when the HVC condition clears if you want.... By shorting a pin you can set it up so that the LVC opto just shorts out the zener diode that holds up the gate voltage for the fet. Currently, the circuit actually opens a relay to latch the condition - but that does not have to happen.

You mean so you don't have to hit the reset button?

[zukster]

Yes - when a cell is below 3.0V it will cut your discharge current by opening the fet. When the cell floats back up, it will allow you to go again. No latching.

Good to know but I prefer the reset button. I'm going to use a bunch of your breaker boards for speed control battery cut-offs for electric wheelchairs for the special needs senior citizens group in my area. I wouldn't want the power circuit kicking back in again once they got going to fast. Getting nervous yet?

Seriously though, for my Son's ebike, if I use the breaker board method to cut off power under LVC, I'd rather the power stay off once its latched.

[methods]

OK three last questions before I part with my money (>$50 x 36 = $1800 )

1.
Is it possible to mix and match 6s, 5s and 4s units? Remember, I'm not doing any of that parallel harness crap. I have 6 blocks of 13s and 6 blocks of 15s. The 3 of the 5s guys would work fine for the 15s blocks, but I would need to use some combination of 5s units and a 4s for the other blocks.

We can do a custom run for you. Since you don't need all the JST-XH-7 headers, we can work out a cheaper assembly method for yours. If you want to solder directly to the boards (i.e. no headers and no JST at all) I can probably drop the price significantly as that is quite a bit of the labor of 36 boards.

2.
Why are there 7 wire pigtails being used to daisychain the boards together? If the boards are to be joined in series, wouldn't you just need one loop of a single strand? I'm not getting this bit.

First, they are 6 wire jumpers, not 7 wires. 3 of the wires are for HVC. 3 of the wires are for LVC.

LVC_Ground
LVC_Signal
LVC_5V

Normally you would only have LVC_Ground and LVC_Signal for an open collector output right? Well these are special high-sensitivity (aka low power) optocouplers that have a darlington pair on the output. This means that by supplying an external 5V you can greatly improve the sensitivity and performance. Since most people are tying into the throttle, 5V, Signal, and Ground are already available and it plugs right in.

HVC_Ground
HVC_Signal
HVC_5V

This is a totally isolated set of signals. There is no electrical connection between the HVC set and the LVC set - total isolation. There is also total isolation between the LVC/HVC and the pack - total isolation.

So when you speak of a single strand of wire.... how would this work?
Typically the way a system like this works (on nearly all instruments) is that the boards sit OPEN all the time. They are all OPEN and hooked in parallel. If any one board gets triggered, it goes CLOSED and now the circuit conducts.

The absolute minimum that could be used here would be 2 strands of wire, right? One that is ground and one that is signal.

BUT - then your HVC and your LVC would be tied electrically. Since the LVC directly ties into the throttle signals it would be a problem for those who want to do custom stuff with the HVC

So - by your logic I could have used 4 wires in the daisy chains.... but that would lower sensitivity.

Regardless - I would have made them in 6 pin anyway because I already have to buy those in bulk for Balance Jumpers - so it makes more sense to stock a large quantity of one type of cable than smaller quantities of different cables.



3.
I don't want a throttle retard (I'm already one of them). I want it to simply sound a buzzer or illuminate an LED. Can this be done?

Absolutely.

Oh, why not, I'll throw another question in while I'm at it If I pay you and your lackey enough, will you do a run of 13s and 15s boards?

You dont have enough money for that bigshot. I would have to come up with a layout, do the layout, produce the PCB's, populate them, test them.... so you would be spending the same amount ++ hours of my time ++ a PCB run. I am guessing that you dont know that it is the same price to do a PCB run of 3 boards as it is to do a run of 90 boards... so for us to do a run for you the PCB's alone would probably be an extra $300 - $500. My time? Priceless. Say I only charge you for 5 hours, that is another $500. Realistically there is all kinds of hidden bullshit in there that people never consider - including the risk that I make a mistake in the layout, delays with the manufacturer, tooling up to test your unique setup, etc.

Maybe one day....

[dougnutz]

Yes - when a cell is below 3.0V it will cut your discharge current by opening the fet. When the cell floats back up, it will allow you to go again. No latching.

Good to know but I prefer the reset button. I'm going to use a bunch of your breaker boards for speed control battery cut-offs for electric wheelchairs for the special needs senior citizens group in my area. I wouldn't want the power circuit kicking back in again once they got going to fast. Getting nervous yet?

Seriously though, for my Son's ebike, if I use the breaker board method to cut off power under LVC, I'd rather the power stay off once its latched.

Are you are using Lipo of wheelchairs?

[zukster]

Are you are using Lipo of wheelchairs?

I'm just trying to get a rise out of Method's by dreaming up strange new ways to misuse his breaker board.

[dougnutz]

http://www.youtube.com/watch?v=yuvRFb7-F0A

[jonescg]

OK three last questions before I part with my money (>$50 x 36 = $1800 )

1.
Is it possible to mix and match 6s, 5s and 4s units? Remember, I'm not doing any of that parallel harness crap. I have 6 blocks of 13s and 6 blocks of 15s. The 3 of the 5s guys would work fine for the 15s blocks, but I would need to use some combination of 5s units and a 4s for the other blocks.

We can do a custom run for you. Since you don't need all the JST-XH-7 headers, we can work out a cheaper assembly method for yours. If you want to solder directly to the boards (i.e. no headers and no JST at all) I can probably drop the price significantly as that is quite a bit of the labor of 36 boards.

Awesome. Cause all 8 of those things take up a lot of space. As long as it fits inside a 40 mm by 50 mm square, I can make it work for a block. It might be prudent to connectorize the cell-board wiring because soldering to the copper blocks takes a bit of careful planning followed by 200 W brute thermal force.

2.
Why are there 7 wire pigtails being used to daisychain the boards together? If the boards are to be joined in series, wouldn't you just need one loop of a single strand? I'm not getting this bit.

First, they are 6 wire jumpers, not 7 wires. 3 of the wires are for HVC. 3 of the wires are for LVC.

LVC_Ground
LVC_Signal
LVC_5V

Normally you would only have LVC_Ground and LVC_Signal for an open collector output right? Well these are special high-sensitivity (aka low power) optocouplers that have a darlington pair on the output. This means that by supplying an external 5V you can greatly improve the sensitivity and performance. Since most people are tying into the throttle, 5V, Signal, and Ground are already available and it plugs right in.

HVC_Ground
HVC_Signal
HVC_5V

This is a totally isolated set of signals. There is no electrical connection between the HVC set and the LVC set - total isolation. There is also total isolation between the LVC/HVC and the pack - total isolation.

So when you speak of a single strand of wire.... how would this work?
Typically the way a system like this works (on nearly all instruments) is that the boards sit OPEN all the time. They are all OPEN and hooked in parallel. If any one board gets triggered, it goes CLOSED and now the circuit conducts.

The absolute minimum that could be used here would be 2 strands of wire, right? One that is ground and one that is signal.

BUT - then your HVC and your LVC would be tied electrically. Since the LVC directly ties into the throttle signals it would be a problem for those who want to do custom stuff with the HVC

So - by your logic I could have used 4 wires in the daisy chains.... but that would lower sensitivity.

Regardless - I would have made them in 6 pin anyway because I already have to buy those in bulk for Balance Jumpers - so it makes more sense to stock a large quantity of one type of cable than smaller quantities of different cables.



OK I think I get how it works. The single wire idea I was referring to was an NC loop on a SPST relay or the like, so when that single loop goes open circuit, the relay trips and sounds an alarm. Rod Dilkes BMS uses this daisy chain system http://ev-power.com.au/IMG/pdf/EVPower_CM_datasheet.pdf

3.
I don't want a throttle retard (I'm already one of them). I want it to simply sound a buzzer or illuminate an LED. Can this be done?

Absolutely.

Oh, why not, I'll throw another question in while I'm at it If I pay you and your lackey enough, will you do a run of 13s and 15s boards?

You dont have enough money for that bigshot. I would have to come up with a layout, do the layout, produce the PCB's, populate them, test them.... so you would be spending the same amount ++ hours of my time ++ a PCB run. I am guessing that you dont know that it is the same price to do a PCB run of 3 boards as it is to do a run of 90 boards... so for us to do a run for you the PCB's alone would probably be an extra $300 - $500. My time? Priceless. Say I only charge you for 5 hours, that is another $500. Realistically there is all kinds of hidden bullshit in there that people never consider - including the risk that I make a mistake in the layout, delays with the manufacturer, tooling up to test your unique setup, etc.

Maybe one day....

Yeah fair enough. However in my case it's more like Phillip J Fry:
You'd be wasting your time.

Yeah well my time is worthless!

[chroot]

Any update for 4s hardcase LVC boards?

[zukster]

Are you checking your email? I was requesting some more boards if available.

[methods]

Yea... I am totally behind on PM's and Emails.
I am in the middle of dismantling my life to transform myself into an international man of mystery... this being the case... every once in a while I have to focus only on shipping to people who have already paid and supporting existing customers. Just cant take on any new work or money

Right now I am doing my taxes - and as soon as I am done (in a few hours) I will catch up on all the orders and pre-sales questions. We are good on stock - so I can probably ship as soon as I receive payment for most folks.

As afar as 4S boards - no, no work has been done.

Our newest product is a system that wirelessly monitors motor temperature and retards throttle based on a predictive algorithm - so that is what we will be working on for the next couple of months. After that, we may come back for the 4S packs.

-methods

[chroot]

4S lvc boards. Hey that's awesome and Let me know when it available. I will need 8.

[Bazaki]

As far as I can see this kit is indeed a perfect solution to avoid overcharging and discharging.

But one year ago a friend of mine did ride his ebike completely empty with some cells at 1 or 2 volts, one day later we did charge that pack and some cells did not charge and stay around 1,5v and sit there while other cells did charge, (we did balance charge the 6s pack ) after a while those unchargeable 1,5v cells were getting hot, so we stopped charging because I think they will explode.

And since we are humans that can make mistakes and many of us have had some Low voltage accidents I wonder if the situation as I described above will be avoided.....

I'm afraid with bulkcharging the charger will continue because the kit will not cut off since it does not a detect high voltage nor a low voltage, or did I miss something.


Besides this I do want the kit because it is much safer !

[bjosta]

I'm afraid with bulkcharging the charger will continue because the kit will not cut off since it does not a detect high voltage nor a low voltage, or did I miss something.

Hmm maybe I didn't understand what you meant.
This product will protect you while bulk charging so it stops the charger if any cell reaches 4.3v. It will protect you from over discharging while running your bike since it will cut throttle if any cell reaches below 3.0v.

[Bazaki]

What I meant if for some reason the cells will be about 1 or 2 v per cell and are not able to take a charge they will get hot and probably catch fire.

With a LVC breaker we almost eliminate this situation but after parking your bike for a few weeks and the contact is still on, or the controller is taking a few mA, maybe an alarm or just some selfdischaring, there is a risk that some cells drop to this 1 or 2v and can't take the charge. A cell log has the feature that it can beep at a given voltage difference, for example 70 mV. It is just a thought, I do love this kit based on what I have been reading at this topic. Lipo's will never be 100% safe but with this kit and probably cell difference cut off it is getting much and much more safe

[amberwolf]

What I meant if for some reason the cells will be about 1 or 2 v per cell and are not able to take a charge they will get hot and probably catch fire.

If you allow cells to reach that low a voltage, and are brave enough to risk recharging them again, I dare say that you should expect to have problems with them.

If you had these boards on there, then you wouldn't run into this problem in the first place, and even if you did, and decided to charge them back up despite knowing what could happen, then when any of the surviviing cells reached the HVC point, the boards would cut off charging.

If you have drained *all* the cells below a safe point to recharge, they might not charge back like they should, and HVC might not ever be reached, and indeed the pack could fail spectacularly. But you would already know this could happen, and would be charging it in a safe bunker or outside away from anything else flammable, right?

[jonescg]

Hey Methods, when you next do a big custom batch of these guys, is it possible to get right-angle JSTs soldered onto the boards? I'm trying to get as low a profile setup as possible.
Cheers mate,
Chris

[methods]

No - that would cause the PCB to be much larger. I like the 90's too, but they have twice as large of a footprint + room for the wiring to exit, so that makes is 3X the footprint. That literally means 3X the price for me on PCB's - and that is more than I make on each board already.

I know one-off stuff sounds good but the reality is that it is extremely expensive. People think I am charging a lot for these at $50 but the reality is that I use very expensive and particular parts from a specific manufacturer and vendor, I pay an over-educated white dude to populate them, and my profit margin is so tiny that you would blush if I told you. The only reason I am even doing this is to try and learn the ropes so that some day I might actually make money

For now - my goal is typically to just make the money back that I invest and to call what I learn in the process my profit.

-methods

[jonescg]

The footprint of the paralleled connectors below won't concern me as I only need one JST down there, but I see what you mean with the HVC/LVC signal wires. Maybe leave them unsoldered and I can do them myself when I put the pack together?

MS Paint idea attached

[Sacman]

People think I am charging a lot for these at $50 but the reality is that I use very expensive and particular parts from a specific manufacturer and vendor, I pay an over-educated white dude to populate them, and my profit margin is so tiny that you would blush if I told you. The only reason I am even doing this is to try and learn the ropes so that some day I might actually make money

For now - my goal is typically to just make the money back that I invest and to call what I learn in the process my profit.

-methods

Lol... cracks me up. You and your over-educated white dude are diamonds in the ruff and we're lucky to have you both Patrick.

-Sacman

[methods]

ok - I have been beaten down.
We will do a very short run of 4S boards. These will be populated with JST-XH-5 (4S) headers. Only 4 channels will be populated. I put together a spreadsheet to calculate savings and it was almost nothing - so I am going to have to charge $45 each for them. I don't think that is a good deal.... what is the point in saving a few bucks buying 4S packs when you end up having to do a bunch of work to wire them up and pay a ton more for cell protection (assuming you want cell protection).

Anyhow - we will do a few sheets - so that works out to 24 of them. If they sell they sell. If they dont I will feed them to Matthew.
I will post up when they are finished. Parts are not even ordered so don't get excited.

-methods

[chroot]

Hi Methods,

I am running 4s4p (20Ah) will only need 4 lvc boards for 16S, It is not much work to wire them up and you probably right about 24S too much work with the wires.