6s LED Balance indicator

http://www.hobbyking.com/hobbyking/store/__23773__2_6S_LED_Balance_Voltage_Indicator.html

It these LED indicators are accurate, it would be nice to use when riding.

Any experiece with them?



See 6:43

[youtube]HPyeQCkcMUE[/youtube]

Haven't seen that one before. It would be very easy to read while riding. Sure can't read a cellog 8 while riding very easy. Two of them in a water tight case on the bars would be nice, but lots of wiring. To run all that wire to the bars, get some phone cable or something like that. 15 wires or more in a nice sheath, then put jst plugs you need on the ends.

Do yourself a favor, for the bars,, get a Cycleanalyst. You won't regret it. Once you confirm with that device that your pack has no duds in it, all you need is a good reliable watt meter and volt meter. The CA is great, easy to read on the fly day or night, and gives you great info like wh/mi average as you ride.

The stand alone CA is what you want for generic controllers.

dogman dan said:

Haven't seen that one before. It would be very easy to read while riding. Sure can't read a cellog 8 while riding very easy. Two of them in a water tight case on the bars would be nice, but lots of wiring. To run all that wire to the bars, get some phone cable or something like that. 15 wires or more in a nice sheath, then put jst plugs you need on the ends.

Do yourself a favor, for the bars,, get a Cycleanalyst. You won't regret it. Once you confirm with that device that your pack has no duds in it, all you need is a good reliable watt meter and volt meter. The CA is great, easy to read on the fly day or night, and gives you great info like wh/mi average as you ride.

This the one?

http://www.ebay.com/itm/NEW-Cycle-A...913049?hash=item2a628b26d9:g:mKwAAMXQlgtS2GO3

The stand alone CA is what you want for generic controllers.

Click to expand...

An LED indicator would be great for charging. It is what I have on each of my Walmart Boosters.

Let's say I want to charge a 20s battery and I use both a BMS abd the LED indicators,

If I limit the charging current to say 3 Amps, could I apply 90 V as the charging Voltage?

Simply watch the LED's to determine if there is a weak cell.

I agree that it probably does not pay to ride with them,

Yeah, that's it. You can get it straight from Justin though. This model here is the stand alone one you need. http://www.ebikes.ca/shop/ebike-parts/cycle-analysts/ca-sa.html

Maybe you don't know, but Justin invented the CA, and the reason this forum is commercial free is because his company Grin Technology pays the bills for this site to be a free discussion forum.

No experince with them myself, but the comments/etc on the HK page show a couple of issues:

--one cell column doesn't work; it always stays all LEDs on. Design problem from what it says there.
--unit is powered from the first two cells, rather than all of them, so it will unbalance your battery during discharge or just sitting there if left connected, and slow down or potentially prevent balancing during charging, depending on the rate at which your BMS is able to balance cells (shunt off current from full ones) vs the currentn used to run this device.

If those two problems didn't exist, I'd love to use these kind of devices on my "dashboard" just cuz I love lights, and even though I might not have them turned on all the time, they'd be useful for testing and diagnosis of issues and monitorinig a pack during a long trip when I may get down to the bottom end of it's capacity, to be sure I doon't run a cell too far down I don't use a BMS on my main EIG pack; been unnecessary so far, and a trustworthy one that could deal out 100A (+) is more than I would be willingn to pay).

amberwolf said:

No experince with them myself, but the comments/etc on the HK page show a couple of issues:

--one cell column doesn't work; it always stays all LEDs on. Design problem from what it says there.
--unit is powered from the first two cells, rather than all of them, so it will unbalance your battery during discharge or just sitting there if left connected, and slow down or potentially prevent balancing during charging, depending on the rate at which your BMS is able to balance cells (shunt off current from full ones) vs the currentn used to run this device.

If those two problems didn't exist, I'd love to use these kind of devices on my "dashboard" just cuz I love lights, and even though I might not have them turned on all the time, they'd be useful for testing and diagnosis of issues and monitorinig a pack during a long trip when I may get down to the bottom end of it's capacity, to be sure I doon't run a cell too far down I don't use a BMS on my main EIG pack; been unnecessary so far, and a trustworthy one that could deal out 100A (+) is more than I would be willingn to pay).

Click to expand...

It would be nice to have a clear cell comparison during charging.

One could design a cutoff charger: Example if the 4.1V LED lights up, react.

The power drain issue should be minimal during charging.

Maybe.

Playing devil's advocate, let's assume the boards might actually pull significant current:

You could be looking at anywhere from 5-50mA per LED, so what is that--7 leds x 6 columns? Let's be conservative, and call it 5mA x 7 x 6, gets about 210mA; plus whatever the MCU uses, all pulled off just two cells (assuming the comments on taht page are correct).

That would explian why the boards get as warm as described--that's probably about 10 watts of power in that little space. Could be even more, but I doubt it would be a lot more, and oculd be less.

Anyway, 210mA is a fair bit of current to be draining differently from two cells (or cell groups) out of a pack, during charge *or* discharge. At least some of the balncing circuits Iv'e seen on varous BMS units can't hdo even 100mA balance currents, so this would be unbalaicng cells much faster than they can be balanced. :/ Even if it's only half the calculated curretn above, that's still as much as the whole capablity of bht ebalancing curent on at least some BMS units. (and some probably cna't even do 100mA balance current).

So I can imagine systems taht these things would cause pretty bad balance problems if they were left attached for longer than just a check now and then.

Of course, they might take far far less current than that, and so they might not cause any problems at all.

Yeah,, we need things like this that draw from all 6 cells to run. Usually just cell one, which is why you don't leave a cellog, or similar device plugged in all the time.

The way I use them,, run till I know I'm down to 10% charge left,, then if I must drain to 100% empty, put the device on for the last 10%. Rarely need that last 10%, but something that shows you the voltage of the cell you know is the lowest capacity is what you need then. Stop when your weak cell is done, regardless of how the others are doing.

dogman dan said:

Yeah,, we need things like this that draw from all 6 cells to run. Usually just cell one, which is why you don't leave a cellog, or similar device plugged in all the time.

The way I use them,, run till I know I'm down to 10% charge left,, then if I must drain to 100% empty, put the device on for the last 10%. Rarely need that last 10%, but something that shows you the voltage of the cell you know is the lowest capacity is what you need then. Stop when your weak cell is done, regardless of how the others are doing.

Click to expand...

Yeah,, we need things like this that draw from all 6 cells to run. Good idea of sharing the load.

Another way is to light only the highest Voltage LED.

"Thus 5mA x 7 x 6, gets about 210mA" and therefore a single lit LED would be 6 x 5 or 30 mA.

Another idea is to add a pushbutton power switch for quick readings, or possibly a timer that flashes the readings every 5 minutes or so.

Check this test video out:

http://www.ebay.com/itm/RGB-MCU-Adj...el-Indicator-Meter-Dual-Channel-/181768021804