Thursday, February 13, 2014

Bites

Been mucking around some more with the DC charging. The firmware is not fully functional but the reason is because there was little interest in DC charging with the controller. The good news is however that the new updated AC charging scheme is actually usable with DC charging as long as you setup the transformer sensing circuit. That however requires you to have an AC source as well as a DC source. Its not as elegant as I'd like but have put in my piece to Synkromotive to see if they can do a similar sensing scheme but use DC instead of AC. If that is the case it will open the DC charging for anyone with a Synkromotive controller and allow you if you want to use AC as well. I like the DC route because it can provide very high input currents for super fast charging if you have the proper DC source. My external inductor works great. The problem with the current DC firmware is not the DC charging portion but switching back to drive mode is one single setup. I want no complex setups or setups that require more than one switch to make work. It should be able to be setup without having to use your computer to switch from drive to charge and back and should not require a computer to determine if your charging from AC or DC. So its my hope that this will all come together soon.

If you have the ability to charge from DC it would open up using old golf cart chargers and welders and even directly from solar panels or banks of batteries if you have an off grid array. If you happen to be at an RV site you can just plug into AC but you'd have to have on board a transformer to step down 110 or 220 to an acceptable level for charging your pack.

I think its a perfect move to super fast charging from a multitude of sources all in one package. No expensive chargers that are limited to one pack voltage.

It is my hope that there will be a true interest when we prove it is quite a viable thing. One controller and little else.

Can any one say controller/charger in one? Who else can do this? I can also charge from 24 volts to a max of 192. Who else can do that? None.

2 comments:

  1. I'm looking around for DC chargers for my conversion. Using the motor coil as an inductor scares me, so it is good to hear you are having success with an external coil. The 192 volt max is not quite high enough for my 60 cell pack.

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  2. Joey,
    The max charge is not 192 volts. The max charge would be about 213 volts if you charge to 3.55 volts per cell. Using the AC charge algorithm with an external inductor will do the trick nicely. If all you have is a DC source the controller will charge up to that 213 volts as well. Just be sure that the voltage source is lower than the lowest that pack would be after discharge. That included using AC or DC charging. When you use AC you also rectify the AC to DC so in fact you are still doing DC charging but you can use the AC current from your 110 outlet. That requires you to have a high voltage pack of either 58 or 60 cells.

    Using the motor field is easy to do and not at all going to hurt your motor. If you plan on 150amp current charging you might want to have an external cooling fan to run through your motor while charging. If not you can just use an external inductor in place of the motor fields. I was successful at up to 45 amps into the pack using the external inductor. That is an excellent charge rate. Inductor did not get warm but the charge was not for long. If you need information on inductors I can get some info for you. My inductor came from some tossed out medical equipment and is of excellent quality. The more inductance the better. I could still use a larger one but what I currently have is going to be excellent.

    Pete :)

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