Good LVD + relay combination for 12V 100 ah 3C pack?

[SunEagle]

Why does everyone here assume I've already built what I'm talking about? I like to research things before I build anything. This is all just talk right. It's also a toy system for my own experimentation. I am going to buy some 4/0 cable today though.

I guess with the 40 years of electrical experience behind me I tend to worry about people getting hurt (I have seen it many times) therefore I try to raise the red flag to warn people about the hazards of electrical circuits.

When you purchase that 4/0 cable make sure you get a certified lug compression system or you could end up with less than desired krimps on the terminal lugs which will increase the resistance and heat generated.

[createthis]

But the amount of amps you will be drawing on that 4/0 cable may eventually break it down. I hope you have taken precautions to protect the wire with the correct fusing and insulated all of the terminal points.

Why does everyone here assume I've already built what I'm talking about? I like to research things before I build anything. This is all just talk right. It's also a toy system for my own experimentation. I am going to buy some 4/0 cable today though.

[SunEagle]

Yeah. I was looking at inverters last night. A 2000W inverter will require less than six feet of 3/0 wire between the battery and inverter. A 2800W inverter will require less than six feet of 4/0 wire.

Kinda cool though. You can run air conditioners off of that.

But the amount of amps you will be drawing on that 4/0 cable may eventually break it down. I hope you have taken precautions to protect the wire with the correct fusing and insulated all of the terminal points.

[createthis]

Yow ! 100A on a 12V system ?

Yeah. I was looking at inverters last night. A 2000W inverter will require less than six feet of 3/0 wire between the battery and inverter. A 2800W inverter will require less than six feet of 4/0 wire.

Kinda cool though. You can run air conditioners off of that.

[Mike90250]

Yow ! 100A on a 12V system ?

[createthis]

Maybe I'm thinking about this the wrong way. Most inverters have a remote switch option. Maybe a simple low current circuit like this, designed to turn off the inverter at my voltage set point is the answer: https://youtu.be/0q8uq5ntjvI

I doubt I'll ever need an LVD for DC loads. They're just typically lower current. But if I do, I have an APO3 sitting around from a previous project that I could use inline.

[createthis]

How about a solid state relay ? (SSR, not a SCR) https://en.wikipedia.org/wiki/Solid-state_relay
takes some looking to find good DC ones., digi-key has them, and a good search engine
http://www.digikey.com/product-searc...=0&pageSize=25
don't forget they often need some heat sinking

I can't find any SSRs over 100A. This one might work if 100A is all I want: http://www.digikey.com/product-detai...685-ND/2060413
It's expensive: $142
Also, I can't tell from that page how much power it draws.

I was thinking something more along the lines of a magnetic latching contactor.

[Mike90250]

How about a solid state relay ? (SSR, not a SCR) https://en.wikipedia.org/wiki/Solid-state_relay
takes some looking to find good DC ones., digi-key has them, and a good search engine

http://www.digikey.com/product-search/en/relays/solid-state-relays/1048664?k=&pv434=88&pv434=90&pv434=92&pv434=95&pv434=98&pv434=100&pv434=102&pv434=148&FV=fff40010%2Cfff80058%2Ca40155&mnonly=0&newproducts=0&ColumnSort=0&page=1&quantity=0&ptm=0&fid=0&pageSize=25

don't forget they often need some heat sinking

[createthis]

I've got a GBS 100ah LifePO4 pack I've been sitting on for a couple of months. I finally have time to go through the bottom balancing procedure, so I've made my list of things to do in order, and now I'm starting to think about operating the pack on a regular basis. Which means I'll need to get my LVD operational sometime soon.

I bought this: http://www.amazon.com/LVD-Low-Voltag.../dp/B01B52H98C which comes with this wiring diagram: http://jumpycalm.com/file/LVD.pdf
That LVD has a disconnect voltage of 11.6V on a 15 second delay, which is a bit low for sub-C operation, but I think it'll be fine.

The C rating for this pack is 3C, so, while I'll probably never draw anywhere close to 3C from the pack, I guess I should buy a 12V 300 amp relay?

I see this 12V 150 amp golf cart solenoid: http://www.amazon.com/CONTINUOUS-SOL.../dp/B008R1T5IM
Looks like it draws 6 watts when it's on. Seems like a fairly large power draw. Is there a more efficient way to do this?

Thanks.