[ausev] discrete charging

[Joby Wieser]

Tom, 

I am doing this, kind of.  When I got my little E-truck it ran on 48 volts, i replaced the home made charger with a 16 amp 48 volt charger from Japler-Schauer.  I quickly found out 48 volts was not enough to keep up with normal city traffic and it felt like i was mentally pushing the truck around, always concentration on getting the maximum acceleration possible.  I added 4 more T-105 6 volt batteries in the trunk.  At 72 volts the little guy became zippy and fun to drive.  Not wanting to waste my investment in the 48 volt charger I bought two 12 volt smart chargers ($35.00 each) for the new battery's each one charges two of them.  Later I added one more T-105 with its own 6 volt charger because I had room for it and I knew my Altrax 72 volt controller is ok up to 90 volts. I do notice the difference with the extra 6 volts.   

The only thing you have to make sure of is that there is no input to output continuity on any of the chargers. Some bond the AC neutral or ground wire to the negative output contact believing this makes it safer.  Most people recommend keeping the traction voltage isolated from the car frame since the 12 volt system uses it as the negative connection.

If the old Jack and heintz motor ever burns up I’m going to switch to 12 , 12 volt batteries and just buy 12 individual smart chargers for them.  That would cost less than $500 and as you noted inherently have individual battery management.

Maybe one of the professional retrofitters has a good reason not to but it seems to be working for me.

Joby in Fredericksburg






> Hi, 
> I was wondering if anyone has built or thought of
> displacing the cost of a large high voltage pack charger
> with multiple smaller 12V battery chargers that could run in
> parallel on a series connected pack, each with
> microprocessor controlled independent three stage charge
> regime (either IUU, IUI).  On the surface it seems doable: A
> 30 A vector charger can be had for less than 80 bucks.  12
> of those would be $960 - far less than a Manzanita, and with
> implicit charge equalization. 
> What am I missing?
> Regards,
> Tom
>