# How many volts would you put to this controller?



## Tubularfab (Sep 25, 2008)

I was wondering how many volts some of you more experienced controller people (i.e. Tesserat, etc) would you run this Sevcon SC2000 controller at?










It's the 80v dual drive unit - SC2x85... I'm wanting to run as high as I can get away with, but don't care to blow the controller up, either. I really wish it was the 96v unit as that would be an ideal battery size to go along with my 48v Zivans... 

I'm thinking I'll probably go with 8 volt golf cart batteries... 

Thank you,
Jason


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## TheSGC (Nov 15, 2007)

Don't use anymore than the 80 volts nominal, so ten of the 8 volt batteries in series. Those batteries would probably read 84 volts when fully charged and that would probably be the safest limit.


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## Tubularfab (Sep 25, 2008)

I was kind of wondering how high a 7 x 12volt battery pack would go at full charge. I forgot to mention that.


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## TheSGC (Nov 15, 2007)

Tubularfab said:


> I was kind of wondering how high a 7 x 12volt battery pack would go at full charge. I forgot to mention that.


That would be 84 volts nominal and probably be around 89 volts fully charged. 

Just for comparison, my 96 volt system reads about 102 volts when fully charged.


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## Tesseract (Sep 27, 2008)

tubularfab - I can't seem to find that model of controller on Sevcon's website, but you can count on a fully charged 12V lead-acid battery having a "surface charge" of 12.8 to 13.0V depending on the temperature.

I strongly recommend you ask Sevcon this question rather than rely on any of us - frankly, there is a lack of clarity in this field between nominal battery voltage (i.e. - 12V) and actual battery voltage (10.5 to 12.8V). One *assumes* that a 96V controller is meant to be used with an 8 x 12V pack, but what if they said 96V because the MOSFETs inside are 100V rated??? *I* definitely wouldn't use that controller with an 8 x 12V pack because at full charge the pack will actually read 102.4 and during charging, if the controller is left connected even via a precharge resistor it will see up to 115V (14.4V per battery).


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## Tubularfab (Sep 25, 2008)

Yep, this controller is old enough now that they no longer have it listed on the website. The Powerpak pretty much superceded it. The Sevcon USA tech said not to go over 80v nominal, but it seemed to me like you might be able to cheat that up to 84 nominal and just stay within the 100v limit they post in the specs. It also seemed odd that they'd make two controllers that were the same dimensionally and logically where one was rated 72 - 80 and the other was 72 - 96... Know what I mean? 

Oh well, I guess I'll just stick to 80v nominal to be safe. I was looking at the Energizer golf cart batteries yesterday at Sam's but was disappointed to see the 8volt versions had about half the AH rating of the 6 volts. I don't think there's as much disparity in the Trojans b etween the 2 sizes. 

Thanks for the replies guys!


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