Electric Helicopter !

An helicopter too can be electric ...

Check out this short video from a Belgium TV channel

The rotor blades are made of very specific materials, lowering the power requirement to lift the helicopter and move it





The company AeroSkyLux is trying to cross the ocean with a small airplane, consuming only 2kW of battery power ... this is quite low !

LiFePO4 ESS - Testing, testing, & testing ...

Still testing a lot my LiFePO4 DIY ESS and here are some graphs and videos from yesterday: the ESS power generation "sticks" to my home power usage, and I like that :-)

Wattson Power graphs: Evening

Morning

May 3rd and 4th

LiFePO4 DIY ESS - Charger Stuff

If you remember the last time I got 3 24V LiFePO4 Chargers, one of them did not blow any air and went into an over-temperature situation; I had my Hong Kong contact send me another one and it arrived last night


The new charger is exactly like the six others, except this blue sticker instead of orange

Only now I decided to open the problem charger, and discovered that its fan connector was simply not plugged into the charger PCB ... This was easy to fix ! :-)

I then replugged it the the ESS Control Board / EMS to test it and the fan started spinning right away :-) 

Now, let's prepare this new charger to connect it with the other ones: 

Always the same thing: remove the original US AC plug, strip the wires and apply solder to make it stronger; On the DC side, remove the plug, strip the wires and solder 8mm lug on positive and 6mm lug for negative 

Done !

So I now have 7 Low Power Chargers to feed my battery pack, and had to plug 2 on the same AC port, together pushing 650W

The stack is getting a bit high with 7 chargers !

2 chargers are connected to the same AC port

7 x 92W = 650W (roughly)

It is tight, but all the DC chargers cables fit

This is the new charger positive lug

and the negative one

Testing Tyco Kilovac EV200A1ANA coil with 12V Battery

So this new Tyco Kilovac EV200A1ANA contactor requires an economizer to avoid coil overheating and getting damaged

Talking a lot on the phone and by mail about it with my dad, he told me to see if the coil was realy overheating and that is what I did using a small 12V AGM battery as a 12V source and also wired an ampmeter - in series - to see the current going in 

3,5A showing here and 3A after few minutes

Not showing on this picture but the temperature went up to 30°C when I left the power - 12V @ 3,5A - on the coil leads for more than 5 minutes, so it is getting warm and consuming some power - 36W or more -

I am still reading einteresting stuff online to make a simple economizer with a simple resistor and a capacitor ,in parallel, wired in series with the coil : http://www.diyelectriccar.com/forums/showthread.php/evdl-coil-economizer-13711.html 

Second lot of small chargers received

Another lot of the 3 same small low power - 100W - LiFePO4 chargers arrived in the mail friday and  they will complete the 6 AC inputs on my ESS; The charger side will be able to increment or decrement by 100W the charge of the CALB 8S battery pack to adjust from 0 to 600W