This is why I will not use SSR Solid State Relays instead of Tyco Kilovac contactors

Shopping for components for my DIY ESS Kit #2, I started to look into SSR - Solid State Relays - to maybe replace the expensive Tyco Kilovac contactors, one of the most pricy item in my build, and I need 2 of them for each kit ...

Looking on eBay I found a lot ...

Also I found this interesting video a a SSR maker, explaining how you have to install it:

I discovered that you need to heat sink it because it will use so much power ! In the video it says the SSR is wasting 1W per Amp of current passing through it: this is huge

Unless you want to create heat, I do not see any good reason to use this; The Kilovac EV200AAANA from Tyco uses only 1.7W when the contact is closed, and for whatever amount of current passing through this contact, and it can be a lot !

So I guess I will keep using Kilovac for my build :

It is an investment but a good one for safety - reliable cut off - and efficiency - 1.7W used only -

Electric VW Transporter Episode 8

The good work continues ...


"In this episode we install the heater, instrumentation, and throttle control"

More info on his website: www.EV4Unow.com

DIY ESS - Ampmeter between ESC and GTI #1

Yesterday I added an Ampmeter between the ESC - Electronic Speed Controller - and the GTI #1 - Grid Tie Inverter - to see the Amps going through 

Here are two videos shot last night: See the needle moving as the power increases and descreases

Done - New GTI interconnects for the DIY ESS

I finally found time to make these short and clean interconnects for the Grid Tie Inverters stack and tested them (Video at the end of this post)

After cutting the 2.5mm2 electric wire to the right length, a little bending on each end, and using a good soldering iron, I could easily make the 6 pairs of 8mm lugs + wire interconnects 

A littler piece of thick paper to make a pattern for the next ones

Fits very nicely after a little adjustment  

Soldering quickly , filling solder inside the hole without have the plastic burn !

There is a good contact between the lug and the terminal after screwing the nut

Adding more inverters to the stack

BEFORE : The grid tie inverters already in use and wired

4 brand new ones received recently that will soon be part of the ESS

AFTER : The same stack with the new interconnects

DC Power is ON (GTI Mode) and the first inverter's AC side is switched ON 

Overview of the Grid Tie Inverters stack, Battery Pack, Control Board, and Wattson in the back

The whole stack is ON (DC & AC) and after long minutes of test, nothing is heating up (wires, lugs, connections) 

Net usage is low

A little video of the ESS fully using its 6 GTIs (out of 8, 2 not wired yet) going up to 1200W +



BTW, this is what I was watching on Youtube at the same time:  Daft Punk - Get Lucky



ESS overview

and this is Wattson Anywhere's Graphs for this good test sunday (click screen capture for direct link to my live graph)
 

LiFePO4 ESS update - 1000W Produced and DC Breaker swap

I had a problem with this 100A DC breaker, that was not handling 100A, but breaking the battery pack after all my Grid Tie Inverters would come on for few minutes producing 1000W all together

So we have 1000W produced and fed by into the Grid, plus some heat wasted for each GTI, let's say 200W (?) more, all this coming from the battery pack energy: 1200W / 24V = 50A
So this breaker was more like a 50A DC breaker in the end ....

The not really 100A DC breaker

A real (I hope) 100A DC breaker from the Enginer Prius PHEV Kit 

New position (on the floor) for this new breaker

A bar of copper is linking the bottom to top cells groups

With this new real 100A DC breaker, the ESS can hold the produced 1000W for long periods of time without any problem :-)