# Manzanita DIP Switches -(cheap BMS, VoltBlochers) please, need help



## tomofreno (Mar 3, 2009)

Leave the dip switches set as the manual says. You use the Regbus input to turn the charger off by connecting Regbus pin1, which is +5V, to pin2. A voltage larger than about 4.5V on pin2 should shut off the charger. You can also connect a resistive divider between Regbus pins 1, 2, and 4 so the charger continues charging but at a lower current output. For example you might want to cut back current to 1 or 2A with an HVC signal so the rest of the cells continue charging while the high voltage cell is shunted. A relay and 1k resistor between pins 1&2 and 10k between pins 2&4 would give 4.54V on pin 2, shutting down the charger. 

With dip switch 3 on, a "hot reg" signal to Regbus pin 2 starts the charger timer. I don't know if the voltage must be greater than 4.5V or any voltage will do it. You'll have to check, because if a lower voltage won't turn on the timer, then the charger will just continue putting out the lower current and not shut off. If you want to cut back to 1-2A for balancing, you will need the timer activated at the same time so it shuts off the charger when it times out.

The Voltblocher (VB) optorelay likely cannot be able to handle the current to connect pins 1&2, so you may need to use it to turn on another relay between these two pins. This relay must require low current input - less than the max output current of the VB relay. I bought International Rectifier PVN012APbF N.O. mosfet photorelay, which handles up to 6A, has very low on resistance, and requires only 15mA input, for this.

In this case you would connect 12V to one input of the IR relay, and the positive terminal of the VB HVC to the other. The negative VB HVC terminal would be connected to ground, so when the VB optorelay turns on it turns on the IR relay. The outputs of the IR relay are connected to pins 1&2 on the Regbus input, with or without a resistive voltage divider.

I haven't actually tried this as I had problems with my VBs and removed them, so proceed with caution.


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## jtgreeson (Aug 14, 2009)

Tom, Thanks for the quick reply! That IR pvn012apbf looks great to use between the VB's and the RegBus. Would you comment on my planned use of them? (I've got limited experience with circuits):

I'll connect +12v to pin 1 on the IR pvn012apbf, -12v to screw #2 on VB (which is #7 on the LTV-826, emitter), #2 on the IR connected to #1 on VB ( the collector, pin 8). I read the datasheet on the IR and it has a 25mA limit to the input. Will this be exceeded by the above wiring?

Output side: IR pins 4 & 6 connected to RegBus #1, pin 5 to RegBus #2. This will shut down the charger with a HVC signal from the VB's. Charger DIP switched set to: 1-on, 2-off, 3-on, 4-on, 7-off per the manual.

I would like to know the effect that those DIP switches have when the RegBus pins 1 and 2 are connected. It would be nice to trigger the Timer fuction of the Charger.

Again , Thanks.


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## jtgreeson (Aug 14, 2009)

Tom,

When you said in your reply: "With dip switch 3 on, a "hot reg" signal to Regbus pin 2 starts the charger timer..." did you mean if Dip #3 is "on" then shorting Pin 1 & 2 will start the timer function?

That would be useful if one wanted to switch to constant voltage mode ( the Timer mode with blue led flashing) when the first HVC cell signal is reached.


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## tomofreno (Mar 3, 2009)

> When you said in your reply: "With dip switch 3 on, a "hot reg" signal to Regbus pin 2 starts the charger timer..." did you mean if Dip #3 is "on" then shorting Pin 1 & 2 will start the timer function?


 That's correct. When the Rudman Regulators get hot they put 5V to Regbus input pin2 to shut down the charger until they are cool, so a "hot reg" signal means 5V to pin2.

The input to the PVN012 is pins 1&2, so +12V is connected to pin1, and VB terminal8 is connected to pin2. VB terminal7 is connected to chassis ground. When the VB LV286 turns on it connects pin2 to ground, turning on the PVN012.

I believe the PVN012 has lower on resistance using outputs 6 and 5 rather than 6 and 4, so I had planned to connect Regbus pin1 to PVN012 pin6, connect a 1kOhm resistor to PVN012 pin5, and a 10k resistor in series with the 1k to Regbus pin4. Then when the PVN012 turns on there will be 4.54V on Regbus input pin2, turning off the charger. As I mentioned, if you want to just cut back the charger current, use a smaller divider ratio to put a smaller voltage on Regbus pin2. But as I said, I don't know how much voltage on Regbus pin2 is required to trigger the timer. You will need it triggered to shut of the charger.

Also beware that the Regbus has the full AC input voltage on it since the charger is non-isolated. So don't connect the resistive divider on the Regbus input to chassis ground! Connect it to pin4. And again, I haven't implemented this, so there may be something I overlooked, proceed with caution.


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## jtgreeson (Aug 14, 2009)

Got it. Thanks for the chassis warning and the other info.


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## dimitri (May 16, 2008)

Tom,

this would be the diagram to interface MiniBMS with Manzanita charger. Please confirm and I will add it to the user manual later.

Thanks


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## tomofreno (Mar 3, 2009)

> Please confirm and I will add it to the user manual later.


 That is what the Elithion documentation shows, just a relay between pins1 and 2, and should work to shut off the charger. I planned to use the resistive divider as described in my last post here, as I thought the resistors would result in less voltage spiking, maybe its not an issue. If you want to use the minibms with shunts and reduce output current to 1 - 2A for a while to top balance cells, you will need to use the resistive divider with lower voltage on pin2. Like I said, not sure how much voltage is required to trigger the timer, and it must be triggered in this case or the charger will not shut off. I may cobble together a resistor, pot, and switch and test this sometime over the next week to see how much I can cut back the charger current and if it still triggers the timer. But at this time, I don't intend to top balance, so I don't have a great deal of interest in it.


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## tomofreno (Mar 3, 2009)

I did some testing today. The PVN012 relay turns on with 12.8V to it through a 800 Ohm resistor (800 Ohm and 12.8V gives about 16mA current through the input of the relay, about in the middle of it's range - you will need to use this current limiting resistor jt). I varied the voltage on Regbus pin2 with a pot in a resistive divider on the output of the relay. It requires about 2.5V to trigger the timer (2.48V did not, 2.51V did), but this did not affect the current output of the charger, it remained charging at 20A. Applying about 3.15V to pin2 triggered the timer and and cut back the current immediately from about 20A to 13A. Applying 3.75V to Regbus pin2 triggered the timer and cut back the current from 20A to 2.0A. Shorting Regbus pin2 to Regbus pin1 cut the current output to zero. Also, the timer resets every time (with the dip switch settings Rich recommends), so I could disconnect the 12V turning off the relay and the timer would go off, current would go back to full setting, reconnect the 12V and the timer came back on, current reduced.

So it seems to work. You will need to experiment with the divider ratio you require to cut back your normal charge current to 2A or less when the HVC signal goes high and a shunt turns on.

Tom


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## jtgreeson (Aug 14, 2009)

Excellent post Tom. Thanks. 

Please just confirm what your DIP settings were during your test so I don't make a mistake.

Thanks, Dimitri, for the Hepa circuit you posted. I'll be using that.


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## tomofreno (Mar 3, 2009)

I used the dip switch settings in the manzanita manual: switches 1,3,4 on the rest off. I just realized I misspoke in an earlier post and said you want lower voltage on pin2 to cut back to a smaller current. It should be clear from my last post you want the opposite, higher voltage cuts the charger back to lower current. Over about 4.5V shuts the current output down to zero.


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## jtgreeson (Aug 14, 2009)

I got my Manzanita PFC-30 and played around with dip switches while charging a 24 volt lead acid. Here's an update on what I discovered and my "Plan" for High Voltage protection. It might help others and I invite comments or any corrections you might have:



Dip Switch #1 turns on timer when peak voltage limit is reached. With it off the charger still goes into constant voltage (CV) mode but never turns off.

Dip Switch #3, when on, allows timer to start when regbus pin 1 connected to pin 2. 

Dip Switch #4 is described in the manual as "Reg buss disable". If it is on the timer will be reset each time Pins 1 and 2 are disconnected. If pins remain connected for the time the timer is set then the charger turns off and remains off. The minimum time the timer can be set is about 15 min.

If Dip Switch #4 is on when pins 1 & 2 are shorted then the timer starts and turns off the charger when it's time runs out. If pins 1 & 2 are disconnected the charger goes back to max charge but the timer still runs.


I plan on a "simple bms" to protect my ThunderSky LiFePo's using the 48 VoltBlochers I already have. My plan is to set Dip Switches 1 and 3 on, the rest off. I measured 5 miliamps (mA) between pins 1 and 2 so I believe I can connect them directly to all the opto HVC outputs of the VoltBlochers. I have calibrated all VoltBlochers to 3.8 volts at which they will start shunting and send a signal to turn off the charger and start the timer set at 15 min. (I will modify the circuit if I get any charger on/off oscilation) I will have a switch to turn off this High Voltage protection circuit if I wish to allow the VoltBlochers to shunt and top balance. I will set charging voltage limit to 3.65 volts average cell voltage (175.2 v for my 48 cell pack) The Voltblochers should not ever send a HV signal or shunt if the cells stay in balance. They should protect a cell overvolt condition if it occurs. The charger should operate as designed with high amp charging until 175.2 volts then constant voltage for 15 min.



Also, I tested the amp draw of each VoltBlocher at 3 volts and they all measured 3.15 to 3.20 mA., so I feel they are all good and will not drain any cells.

I'm toying with the idea to add a timer circuit to the HV signal that would latch it on for 5 minutes and a resistor to limit charging current to 2 amps. Tom described his voltage tests in a post above.

Thanks for any comments.


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## tomofreno (Mar 3, 2009)

> I will set charging voltage limit to 3.65 volts average cell voltage (175.2 v for my 48 cell pack) The Voltblochers should not ever send a HV signal or shunt if the cells stay in balance.


 With HVC set at 3.8V I think this will perform as you expect, with the charger just timing out and HVC never triggered, unless a cell significantly drifts. I have not balanced cells for over 20 charge/discharge cycles now, and have not seen significant change in balance. I plan to operate in a similar way using the minibms which should arrive this week. Currently, I have the charger set so it just times out at about 3.42V/cell (Sky Energy cells, so exponential voltage rise with charging time starts at about 3.45V).

My experience is the Manzanita doesn't have a true "constant voltage" mode. It very gradually cuts back current once the timer starts, and voltage continues to rise. How much seems to be determined by how long the timer is set for, what magnitude charge current is used, and possibly how much pack voltage rises with charging time once the timer is triggered. With the timer set for 45 minutes, current cuts back from 30A to about 23A, then shuts off. With the timer set for 2 hours, current remains above 20A most of that time, cutting back very gradually until near the end when it drops more rapidly to around 4A before timing out. But near the end in this case, some cells were on the exponential rise in voltage with time part of the curve, so that is why I say it may depend on voltage increase - that's approximately when the charge current started dropping more rapidly with time.


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## jtgreeson (Aug 14, 2009)

Thanks, Tom. That's useful information. I will post my charging data/experience when I get to that point.


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