Traction battery discharger shut off.

The B6 can be used for one MODULE at a time. It can only charge up to 10 NiMH cells or so. Maybe 12 (two modules iirc). So not sure how you would want to have this wired up.
Also please note that you should never have two of them charging different Prius modules while they are being fed my the same powersupply (e.g. a carbattery). This will cause fireworks...
I have a few B6's but am not entirely sure you can program the discharge voltage per cel. I know for sure my 80W versions are NOT suited for charging the modules as they do not recognise the deltaV(*) while charging. My 50W version is better in that respect. But this thread is about DIScharging.

For my drawing below, you'd want these voltages:
94V~ for a rectified and buffered 134V=. You could use 2x45V~ or a 2x50V~ windings in series (127V= or 141V= respectively).
71V~ for a rectified and buffered 101V=. You could use 2x35V~ windings in series (99V=).
59V~ for a rectified and buffered 84V=. You could use 2x30V~ windings in series (85V=).



Link full size pic.






(*) DeltaV is how chargers 'know' that a NiCd or NiMH battery is full. If I remember correctly, the voltage of a full battery drops slightly at the moment it reaches the full state. This can be recognised by the charger (probably by a sudden increase in chargingcurrent-demand) so it can switch from charging to trickle charging. If it doesn't recognise this deltaV (delta means difference or change and V stands for Voltage), then it keeps pumping energy into the battery and overheats them which leads to dead batteries. The B6's *can* be programmed to use the deltaV to stop charging AND also limit the maximum amount of energy put into a battery as an extra level of security, but this is only a reliable safeguard if you know the state of charge (SOC) before you start the charging cycle (e.g. you can program it to not charge more than 7500mA into an empty 6500mA Prius battery, but if you think it is half full, then you have to guesstimate that it should stop at 4000mA).


BEWARE I FORGOT TO ADD ANY FUSES IN THE DRAWING! PLEASE DO ADD THIS!!!

 

I bought one of these a while back.
I haven't used it yet as it draws 20mA or so, which is too much for my taste in a battery operated safety switch. The plan was to have it switch an active cooler in my car that switches ON above 13.5V (car on) and switches OFF below 12.8V (car off).

With a voltage divider, I think it should also be suitable for setting a cut-off voltage.

It has a few options*, one of which is undoubtedly to switch the relay OFF when it drops below a certain voltage and never come on again.

A voltage divider is two resistors in series.

If anyone remembers electronics 101, you'll know that if Z1 is 9000 ohms and Z2 is 1000 ohms, it will 'divide' the Vin voltage by 10 so Vout is 1/10th of Vin.
So if Vin is the Prius battery voltage of 250V max, the Vout is 25V max. Which is within the 0-30V range the gizmo can handle.
Set the cut-off voltage at 13.4V (=134V battery voltage) and the relay will switch OFF at this voltage... Use the relay for the dischargecurrent between the battery and the load, and it should work!


I am assuming it feeds everything (powering the chips, the display, the relay) from the powersupply (the 12V input, you'll have to supply yourself externally) and the test voltage input is not needed other than some voltage measurig chip, which, like a digital voltmeter, does not require any current worth mentioning (few uA at most). If this assumption is not correct, then it may need some finetuning.


* it is badly documented and I had some fruitless discussion with the seller, but I eventually found out it has 6 functions iirc.
Which is probably something like this:
Switch ON above a certain set voltage (or OFF when using the other relaycontacts)
Switch ON below a certain set voltage (or OFF when using the other relaycontacts)
Switch OFF between two set voltages
Switch ON above a certain voltage and OFF below another voltage
etc.

EDIT: here's two excerpts from discussion with the seller that should make it easy to figure out what's what:

 

Wow, that's all above my knowledge level. Never did electronics 101!

 

You're very knowledgable in loads of respects, so cool I *finally* found something I might know more about

@JIM77: if I have the time (and energy which is scarcer than my time), I will find said gizmo and test what program you would need (P1, P2,...P7) and if the currentdraw plays an important role (as in: how do I need to modify Z1 and/or Z2 to have an accurate working device). And how to actually wire it up.

Much does depend on the current you draw while discharging, so if you can tell me what load you are using, I might be safer in my advice.

I also wanted to add a warning to my previous post, but I cannot edit it anymore... The 9000 and 1000 ohm resistors need to be 7W versions at least and will get too hot to touch. So 90k and 10k in 1W versions would have been better advice, but I was too lazy to do the calculations... Sorry about that...
After testing, I might end up with e.g. 820k and 100k 1/4W standard resistors, but that is too early to tell.

I intended to use this voltage divider trick for my home-made Prius charger as well: using this meter, but on 330Vmaximum voltage (enough for the 250V Prius battery), but with a 1/10 voltage divider so it stays within the 33V input. It counts the total power that passes through the meter, so it actually counts the kWh (or actually Joules) that you push into the Prius battery. (But I have to manually multiply it by 10, but still I would have an indication of the total capacity put into it).
Since it has the current shunt in the ground-wire, this can be used in this manner.

 

But most timers will be 115VAC (at least plug-in timers), or do you have different timers? A timer as backup sounds of a good plan regardless of any other ways of stopping the discharging. Or the charging for that matter.

If you actually have 200W bulbs, then that is a big load... Almost 2A through a bulb, and 4A on the battery pack.
(I rounded the numbers, so instead of a 200W bulb, I assumed it was 230W for ease of calculation, then two in series is 460W and the voltage is 230V. P(ower)=V(oltage) times I (current). So 460W=230V * I. So I = 2A. Two such sets in parallel means double the current draw, so 4A. The 6.5Ah pack will be discharged in (6.5A times 1 hour divided by 4A = 1.6 hours or about 100 minutes).
When you reach 80V, or 134V will obviously be very dependant on the quality of the battery and isn't an exact science, but probably anywhere between 80 and 130 minutes.

Or you might mean a 50W bulb, which means a 200W total load. Then discharging is about 8 hours.

 

So the 200W bulbs for 2 hours, at what voltage did the battery sit? I would assume it would be near depleted.

800W/230V (assumed average battery voltage during discharge) = 3.5A
3.5A during 2 hours is 7Ah, where the battery is only 6.5Ah.

Keep reminding me to check the Chineese gizmo option. Not sure where you are located and if you can order one.
Did you have any transformers or is that option too difficult?

 

I did some measurements and will record them here, so when I loose the paper I wrote the results on, they are still here on the web

So the device linked to above, or when the link no longer works, google

DC 12V Charging Discharge Switch Control Module Voltage Monitor Switch Control Board Module with Upper and Lower Alarm "

There are 7 programming settings, named P1, P2, etc.
P7 doesn't do anything, so 6 remain. Pushing the first button for a few seconds will show P1, pressing it again will show Voltage(1) and again will show Voltage(2). Again and it is programmed. The second and third button are up and down, so pushing this while in "P1" will show either "P2" or "P7". When in voltage setting mode, it can set the voltage in 0.01V increments.

I set two limits, the first at 10,00V and the second at 15,00V. I did not try setting the first at 15V and the second at 10V (just thought of that while writing this thread) so not sure what that does.

I then raised the voltage from 0 to 30V and then back from 30V to 0V. Results below (including typing error...).


The current running through the sensing input was 1,54mA when inputting 30.8V, and was linear, so the current is 50uA or 0.05mA per volt. There seems to be a measuring resistor of 20k ohm (=30.8V/1.54mA), being Z2 in the drawing in my quoted post.

I obviously cannot promise each unit will be the same (its an unknown Chinese manufacturer...) so experiment at your own risk.

In theory, simply adding a 180k ohm resistor as Z1 will make for a 1/10 voltage divider. But it has to 0.4W (even more when going beyond 250V), so go for at least a 1W resistor. Then you can measure and control anything between 0 and 300V.

Program P5 to a lower voltage of 13.4V and use the common and NO (Normally Open) connection on the PCB near the relay to switch the power between the battery and the load. Connect the battery to the sense or INPUT inputs. Connect the powersupply to a 12V battery or 12V powersupply.
Now the load will be disconnected if the sense input goes below 13.4V, which means the batteryvoltage is below 134V.
Once it shuts off the relay, the only current on the battery is the draw through the sensing circuit. Which is just shy of 1mA. (13.4V times 0.05mA/volt = 0.67mA => 0.67mA x 134V = 0.089W)


If you have any doubt, please contact me, preferably in this thread, so everyone can learn from (my) mistakes or ideas.

Seems I have to correct myself already... The relay is not rated for a DC voltage higher than 30V. So when doing this properly, you should use the relay on this PCB with e.g. 12V to switch a second external relay rated for >250VDC.
These are harder to find, mostly because DC voltages can arc when you try to disconnect them, and the higher the current, the larger the arc can be, hence the further a relay must physically move the contacts apart.

 

The table you displayed shows 168 cells. I can count only 28 cells in my Prius 2004. So for one cell, and dividing from terminations of the whole pack, my successive termination voltages should be 4.8v, 3.6v, and 3.0v. Isn't it?

 

What you are counting is 28 modules.

There are 6 cells per module.

That's where 168 cells come from.

 

Thank you for the quick reply. So if I am oly discharging one module, I should discharge one module down to 4.8v on my first cycle based on the published recommended table by hybridautomotive. You agree?

 

If you are looking at the Hybrid Automotive website, does that mean you have their equipment ?

If so, they have the sequence listed there in regards to what to discharge too.

The intelligent discharger makes the process super easy if you have that.

Good luck and keep us posted.

 

Yes, I use HybridAutomotive 's products, and no, HybridAutomotive has no product to regenerate an individual module. I am using HobbyKing to regenerate a single module. I'm going ahead with 4.8v, 3.6v, and 3.0v. Most settings I found in YouTube is 6.0v which I find too high to be useful. You have helped me a lot today on differntiating a cell from a module as I thought they were the same. Will do, thank you.

 

Yes, that is correct.

 

If a cell is going out, why not replace it?

You've got the right equipment to rebuild a pack and you seem to have peripheral knowledge of how to work in the pack, so that doesn't seem to be a barrier.

If a cell fails, you won't be able to regenerate it.

Good luck .