"Universal Freddy" had a makeover, simplifying it and making it more robust and reliable:
Instead of a dodgy shunt and two ammeter ranges, there is now a single 5A meter without shunt.
The voltage range selection switch is gone.
The best about it is that I now have a 5kw (10kW peak) pure sine wave inverter. Overkill, of course, but unlike the 380W sine wave and 600W modified sine wave inverters, it can handle Universal Freddy (at 58uFreddy setting with shorted output at almost 4A DC). What it means is that I can now charge the Vectux from a 12V DC battery, or a solar system, or a car while on the road. Slowly slowly of course, but also as gently as possible. The inverter can also power the ABCool at the same time to cool the battery if needed.
What I learned from the Vectux allowed me to fix a few NHW10 Prius cars. They have a DC/DC converter that can easily provide the amount of 12V current needed to run Universal Freddy at full bore charging the Vectux. The Prius ICE will occasionally come on to top up it's 240s NiMH battery - of course it is all terribly inefficient compared to grid charging, but works anywhere! I'll have to try out if the 12V output of my Honda 20i generator works for this. I expect it will, particularly when combined with a dual purpose lead-acid battery. Every now and then, when a solar panel is not enough, the 20i will get cranked up to charge the battery. The battery provides 12V DC for the inverter, with plenty of reserve power to start pumps and compressors (fridges, aircon).
Camping trips with reduced environmental footprint are now a possibility: 2A x 12hrs overnight charge = 24Ah full Vectux = 40km of electric fun rides per day. Or a trip home (40km), charge from grid, then back to the campground.
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Special Freddy (SFreddy) is also going well, into incarnation 15 or so:
It charges a NHW10 Prius at 0.4-0.6A while monitoring battery temperature and proper operation of the cooling impellers. I finished the battery-internal part recently, now it is an easy plug-and-charge action to givethe battery an EQ charge every few weeks, or as needed.
I hope to also integrate a solar panel to drive the NHW10 impellers whenever the sun shines (sun shine = it's hot where I live). That will keep the cell temperatures equal and the passenger cabin cooler.
It looks like this (still needs the odd diode here and there):
Now I'm off to learn how to solder some really fat cables so that I can test if that inverter can really do 5kW! It will be sucking around 500A of 12V DC to do it...
You don't solder fat cables. You use crimp lugs. And you need proper crimp tools.
Once you go EV, Gas is history!
Well, there are a great many threads about that sort of topic.
For me, it has long been determined that "Crimp and solder" is the way.
I don't use a proper crimp tool for it, I just squeeze it enough to make a firm connection, Then I solder it.
A butane blow torch did the job this time.
This information may be used entirely at your own risk.
There is always a way if there is no other way!
Hi Mik,
I'd really like to build your Universal Freddy and use it before my pack dies. I'm not an expert in electronics, but have some basics and will ask some help from my prefered electronics component dealer. Would you have some more input to help me on this:
- Pictures of the schema with better resolution, it is difficult to read the correct values on the one on this post
- List of components you used
- Pictures of your actual circuit and box
- Anything that could help me not doing stupid mistake
On vectrix side:
Where to you plug it?
I understood the Vectrix charger needs to be removed, do you unplug manually each time or did you install a switch?
Many thanks for your help
Afo
Hi Afo,
don't build one this way, follow The Lairds advice here: http://visforvoltage.org/forum/7912-nimh-battery-problems-and-cures#comment-45350
This information may be used entirely at your own risk.
There is always a way if there is no other way!