# Shiva Settings...



## GeoMetric (Aug 13, 2010)

I have never used the (minimum battery voltage) setting on my Shiva and would like some insight from Jeff, QER or current owners. I set my MBV very low, so it would not be a factor.

This coming racing season I will be using some very expensive cells and do not want to harm them. My questions:

Under and circumstance will the MBV setting turn-off the controller?
or
Will the MBV setting just lower the amps drawn from the battery to maintain voltage of pack?


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## Qer (May 7, 2008)

GeoMetric said:


> Under and circumstance will the MBV setting turn-off the controller?
> or
> Will the MBV setting just lower the amps drawn from the battery to maintain voltage of pack?


Both, actually. 

[scrapped post]

However, this is much better explained in the manual page 20-22 than my post did (the manual even has a graph!), so I've removed my text to avoid possible confusion or errors from my side...

The manual is here: http://www.evnetics.com/support/downloads/

And even if it doesn't mention the Shiva it's the same software so it works the same. Just with more manly limits!


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## GeoMetric (Aug 13, 2010)

Qer said:


> Both, actually.
> 
> It will start with limit current to try to keep the pack from dropping below minimum voltage. Since this is a bit of trial and error for the controller, it won't be spot on and might vary a few volts for the pack. Ie, if you have a minimum voltage set to, say, 200 Volt you might see some 198 Volt records in the log while the controller struggles to handle the situation. So the minimum voltage setting isn't a absolute limit, rather a target mark for the controller which it then will do it's best to achieve.
> 
> ...


Wow, that's some info to chew on. Thank you QER.
So, if I want to try and limit amperage at some point during the race the MBVL could be set. The safety feature makes sense, but if the voltage drops 10V below that setting the controller will shut off. Hmmmn, I guess it could be used if I allow a cushion for the 10V+ drop possibility.

For an example:

Say I want to use 3000BA for 5 seconds and know the packs voltage will drop to 220V for the first 5 seconds but continue to drop if I keep asking for 3000A, I could set the MBVL at say 210V the 3000A will start to drop when the pack sags to 210V. The problem is if the packs sags to 200V the controller will shut off?


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## Tesseract (Sep 27, 2008)

GeoMetric said:


> ...
> So, if I want to try and limit amperage at some point during the race the MBVL could be set. The safety feature makes sense, but if the voltage drops 10V below that setting the controller will shut off. Hmmmn, I guess it could be used if I allow a cushion for the 10V+ drop possibility.


If the battery voltage drops 10V below the minimum that the controller is trying to maintain, then something has gone wrong with the pack. Either a bad connection, or a bad cell, or it is nearly depleted, etc.

As for what to set the maximum battery current and minimum voltage limits to, that is entirely up to you and/or your battery manufacturer (for liability reasons we will not advise you on this). The Shiva is subtitled "the destroyer" for a good reason.


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## GeoMetric (Aug 13, 2010)

Tesseract said:


> If the battery voltage drops 10V below the minimum that the controller is trying to maintain, then something has gone wrong with the pack. Either a bad connection, or a bad cell, or it is nearly depleted, etc..


Not in all cases, some cells have amp burst ratings for only 3 seconds, then a second lower amp rating for 6 to 10 seconds. During these bursts the voltage will change, since you can't control the BA, using a voltage control is very important. Most racers want the ability to utilize the burst then lower the amps pull to maintain higher voltage. Not all cells deliver the same amps/ voltage, some will get damaged if the burst rating continues past the cells specs. The name "Destroyer" is nice, but not everyone wants to destroy their battery pack.


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## Tesseract (Sep 27, 2008)

GeoMetric said:


> Not in all cases, some cells have amp burst ratings for only 3 seconds, then a second lower amp rating for 6 to 10 seconds. During these bursts the voltage will change, since you can't control the BA, using a voltage control is very important. Most racers want the ability to utilize the burst then lower the amps pull to maintain higher voltage. Not all cells deliver the same amps/ voltage, some will get damaged if the burst rating continues past the cells specs. The name "Destroyer" is nice, but not everyone wants to destroy their battery pack.


Ron, you don't seem to get what I am saying here. When the pack voltage sags down to the programmed minimum voltage a Soliton controller will attempt to maintain that voltage by cutting back on the duty cycle (ie - reducing battery/motor current). Normally a Soliton controller can prevent the pack voltage from sagging more than a couple volts below the programmed minimum, but during abnormal conditions the pack voltage can sag faster than the controller can adjust its duty cycle and once the pack has sagged more than 10V below the programmed minimum the controller opens its main contactors and faults off.

As for protecting the battery pack, once again, that is entirely up to you. If the battery pack can deliver more than 3000A continuous then it is in no danger of being harmed by the Shiva (assuming all of your connections are done well). If it can't deliver 3kA continuously then it is up to you to limit the amount of current and/or time it is subjected to abuse.

Under no circumstances will Evnetics accept ANY responsibility for destroying battery packs, motors, etc., as a result of controller settings.


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## DIYguy (Sep 18, 2008)

It's a very annoying (and necessarily good ) feature . . . that has made me turn my key off and on again multiple times.... as it wouldn't let me draw more power (more than I actually had  lmao)


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## GeoMetric (Aug 13, 2010)

Tesseract said:


> Ron, you don't seem to get what I am saying here. When the pack voltage sags down to the programmed minimum voltage a Soliton controller will attempt to maintain that voltage by cutting back on the duty cycle (ie - reducing battery/motor current). Normally a Soliton controller can prevent the pack voltage from sagging more than a couple volts below the programmed minimum, but during abnormal conditions the pack voltage can sag faster than the controller can adjust its duty cycle and once the pack has sagged more than 10V below the programmed minimum the controller opens its main contactors and faults off.
> 
> As for protecting the battery pack, once again, that is entirely up to you. If the battery pack can deliver more than 3000A continuous then it is in no danger of being harmed by the Shiva (assuming all of your connections are done well). If it can't deliver 3kA continuously then it is up to you to limit the amount of current and/or time it is subjected to abuse.
> 
> Under no circumstances will Evnetics accept ANY responsibility for destroying battery packs, motors, etc., as a result of controller settings.


Okay, I understand how it works. I am now contemplating if I should use the setting to gain additional voltage added at the end of the race, but the last thing I want to happen is both controllers shut off during a run. I guess it could be set much lower just incase of a major failure. Our new pack modules consist of 28P 150amp burst rating of the cylindrical type LFP. Each module will burst 4200A for a few seconds, but I plan on running them lower, and utilize the volts to gain the KW needed.

Also, Jeff please respond to Dennis Berube's email, he needs information on the Shiva.


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## Tesseract (Sep 27, 2008)

GeoMetric said:


> ...but the last thing I want to happen is both controllers shut off during a run.


No, the last thing you want to happen is for the controller to keep sucking current from the pack through a bad connection until it glows white hot and explodes (I have seen that happen and the results, while spectacular, are usually not pretty). 

You can set the two minimum pack voltages (ie - at zero current and at full battery current) artificially low to effectively disable this function, but keep in mind there is no advantage, yet considerable risk, to setting these voltages lower than half the nominal (ie - 200V minimum for a 400V nominal pack).



GeoMetric said:


> Also, Jeff please respond to Dennis Berube's email, he needs information on the Shiva.


Not the appropriate venue for this, Ron. I operate on the assumption that any current or potential Shiva customer would prefer to not be publicly identified as such until they are ready to unleash a can o' whoopass on the track.


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## GeoMetric (Aug 13, 2010)

Tesseract said:


> Not the appropriate venue for this, Ron. I operate on the assumption that any current or potential Shiva customer would prefer to not be publicly identified as such until they are ready to unleash a can o' whoopass on the track.


Jeff, he has gone public with his purchase of a Shiva, it is no secret. Everyone in the racing community knows he purchased one. Dennis is very concerned that you have not responded to his emails yet, please do so today.


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## Tesseract (Sep 27, 2008)

GeoMetric said:


> Jeff, he has gone public with his purchase of a Shiva, it is no secret. Everyone in the racing community knows he purchased one. Dennis is very concerned that you have not responded to his emails yet, please do so today.


I already replied to his email on Sunday...

Regardless of who knows what, I still would prefer that you not make public communications that were assumed to be private by the parties involved. I would think you would appreciate this sort of discretion more than most...


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## GeoMetric (Aug 13, 2010)

Tesseract said:


> I already replied to his email on Sunday...
> 
> Regardless of who knows what, I still would prefer that you not make public communications that were assumed to be private by the parties involved. I would think you would appreciate this sort of discretion more than most...


Okay, I missed his email Sunday night. I am the one who convinced Dennis your Shiva was worth it, so that is why he purchased one. We speak almost everyday, so when he needed info I was contacted and asked to contact you when there was a short delay in response. Thank you for answering his questions.


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