# Charger Recommendation



## rwaudio (May 22, 2008)

SCEV said:


> I think I've finally decided on my battery pack, 68 CALB CA100 cells in series. So I'll be charging in the range of 200V (empty) to 240V (full). Looking for recommendations on a charger, below is what I'm considering so far...
> 
> Brusa NLG513, 3.3kW (I'll only get about 3kW at my voltage), $2k, easily reconfigure able via laptop
> 
> ...


I'd go for the Brusa... or an EMW 10kw since it's in the same price range for the assembled version.


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## SCEV (Apr 10, 2012)

rwaudio said:


> I'd go for the Brusa... or an EMW 10kw since it's in the same price range for the assembled version.


Hmmmm...hadn't seen the EMW one before. Stepping up from 3kW on the Brusa to 10kW would be awfully nice. Are these reliable, easy to configure? I found the 80+ page thred on the charger, but haven't read through it yet.


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## rwaudio (May 22, 2008)

SCEV said:


> Hmmmm...hadn't seen the EMW one before. Stepping up from 3kW on the Brusa to 10kW would be awfully nice. Are these reliable, easy to configure? I found the 80+ page thred on the charger, but haven't read through it yet.


I built one, (plus building another for a friend) it took a bit to get going but it works great. The Brusa is going to be in a different league as far as build quality, but the EMW gives you power!

You can also reconfigure the EMW using the built in display/buttons no need for a laptop.
http://www.emotorwerks.com/emw3/product/fully-assembled-and-tested-charger/


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## dreamer (Feb 28, 2009)

rwaudio said:


> I built one, (plus building another for a friend) it took a bit to get going but it works great. The Brusa is going to be in a different league as far as build quality, but the EMW gives you power!
> 
> You can also reconfigure the EMW using the built in display/buttons no need for a laptop.
> http://www.emotorwerks.com/emw3/product/fully-assembled-and-tested-charger/


What ever happened to your plan to use separate power supplies to charge each cell ?


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## Joey (Oct 12, 2007)

I'm in a similar situation - 60 cells, 180Ah. I don't like that the manzanita isn't isolated. I'm thinking a $560 El Con to hold me over until the evnetics charger becomes available. I'm not sure if this is an option at your voltage.


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## brainzel (Jun 15, 2009)

I'm using a Zivan NG3 (about $900) for daily driving and a second NG3 in parallel if I have to "quick" charge.

This option is nice, but if I could afford it, I would keep one 3kW as on board charger and a second one (probably Zivan) with about 9kW/11kW for quick charge.

I am very satisfied with Zivan so far.
Brusa is too expensive for me.
Elcon/Chennic was an option but just as expensive as Zivan and had no german support at that time.

Michael


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## rwaudio (May 22, 2008)

dreamer said:


> What ever happened to your plan to use separate power supplies to charge each cell ?


I still use it when testing cells or bringing up low cells but it was limited in power, and overall efficiency was less than a PFC charger.

I'll continue to use it, just not in the car.


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## dreamer (Feb 28, 2009)

rwaudio said:


> I still use it when testing cells or bringing up low cells but it was limited in power, and overall efficiency was less than a PFC charger.
> 
> I'll continue to use it, just not in the car.


I thought the real advantage would be not needing a BMS to insure any cell was overcharged. Saving the cost of a BMS plus the lower overall cost seemed like it would be worth lower efficiency.


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## rwaudio (May 22, 2008)

dreamer said:


> I thought the real advantage would be not needing a BMS to insure any cell was overcharged. Saving the cost of a BMS plus the lower overall cost seemed like it would be worth lower efficiency.


Yes I thought so too, however the efficiency does come into play when charging from 120v, the power supply to run the dc/dc converters is about 85-87% efficient, the converters themselves in the current range running from 120v are 82-83% efficient, I could safely draw about 12-13A from the wall, that's about 1000W into the pack.. at best. They also aren't truly CC/CV, they will put out current and never exceed the CV voltage, however they won't maintain *full* current as you approach the CV voltage. This means that as you charge the power continues to drop. It's great if you have no time limits on charging, however if you need to get power in fast it's simply not the best solution.

So in short the system works perfect and is very reliable and can not overcharge a cell. The bad is that without very complex control it's difficult to get decent charge times. It's also tricky to set the system up to make use of 240v. I use it when I want to bring up a cell or group of cells that may or may not be at the same SOC without watching it. It would make a great alternative to a top balancing BMS, taking over from a bulk charger once it hit the CV phase or something, but on it's own it was getting too complex to be practical. At one point I had a small microcontroller and digital pot adjusting the current to each module to optimize power output... this didn't make it past the breadboard stage.

If the EMW 10kw didn't come along I probably would have continued working on it, however at the price and power level the EMW provides it's just a smarter choice.


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## dreamer (Feb 28, 2009)

rwaudio said:


> Yes I thought so too, however the efficiency does come into play when charging from 120v, the power supply to run the dc/dc converters is about 85-87% efficient, the converters themselves in the current range running from 120v are 82-83% efficient, I could safely draw about 12-13A from the wall, that's about 1000W into the pack.. at best. They also aren't truly CC/CV, they will put out current and never exceed the CV voltage, however they won't maintain *full* current as you approach the CV voltage. This means that as you charge the power continues to drop. It's great if you have no time limits on charging, however if you need to get power in fast it's simply not the best solution.
> 
> So in short the system works perfect and is very reliable and can not overcharge a cell. The bad is that without very complex control it's difficult to get decent charge times. It's also tricky to set the system up to make use of 240v. I use it when I want to bring up a cell or group of cells that may or may not be at the same SOC without watching it. It would make a great alternative to a top balancing BMS, taking over from a bulk charger once it hit the CV phase or something, but on it's own it was getting too complex to be practical. At one point I had a small microcontroller and digital pot adjusting the current to each module to optimize power output... this didn't make it past the breadboard stage.
> 
> If the EMW 10kw didn't come along I probably would have continued working on it, however at the price and power level the EMW provides it's just a smarter choice.


So you now have some other voltage cutoff solution for each cell ? What did that add to the cost of the EMW ?


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## rwaudio (May 22, 2008)

dreamer said:


> So you now have some other voltage cutoff solution for each cell ? What did that add to the cost of the EMW ?


Yep, my cell log 8 breakout module....
The NC alarm loop ties into the EMW and will terminate charging when a cell is over a preset voltage. 

Shown being tested by the dc/dc converter charger.


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