Using a high farad cap to survive engine crank

**lakorai** · 03-28-2005, 12:46 AM

Question:

Have any of you guys tried a high farad capacitor to help survive engine crank? I would think a large 1 Farad cap or something like that would work because it can hold an emormous amount of electricity - and caps with their very low ESR are designed for "Deep Cycling" which those regulation circuit/engine crank devices with those APC style backUPS style batteries really aren't (regular lead acid isn't designed for deep quick dischage, though I am sure it works fine).

Though a 1 farad cap probably costs more than an engine crank survivor thing + a lead acid APC style battery. Might have a problem though because you have to hook up inline, though I'm sure you could just hook up the ring terminals from the battery supply and the lead acid "engine crank" battery to the same leads on the invertor.

-LAKORAI

**lakorai** · 03-28-2005, 12:50 AM

The engine cranking item is called a "crank Tank" I believe. www.thecarpcstore.com has it. Wonder if it works good - sure is a hell of allot cheaper than buying an OPUS. I don't really care that much about having a shutdown controller - though I am going to put a button on my dash - that's a NC (normally closed) push button right?

-LAKORAI

**Harrie Coolen** · 03-28-2005, 01:35 AM

euh.. it should be a NO Button (normaly open)

**therussman2002** · 03-28-2005, 09:43 AM

i have a 50farad cap for my system, i should try that out

**MatrixPC** · 03-28-2005, 09:58 AM

Originally Posted by lakorai

Question:

Have any of you guys tried a high farad capacitor to help survive engine crank? I would think a large 1 Farad cap or something like that would work because it can hold an emormous amount of electricity - and caps with their very low ESR are designed for "Deep Cycling" which those regulation circuit/engine crank devices with those APC style backUPS style batteries really aren't (regular lead acid isn't designed for deep quick dischage, though I am sure it works fine).

Though a 1 farad cap probably costs more than an engine crank survivor thing + a lead acid APC style battery. Might have a problem though because you have to hook up inline, though I'm sure you could just hook up the ring terminals from the battery supply and the lead acid "engine crank" battery to the same leads on the invertor.

-LAKORAI

If you do some search on this power forum, then you will know why this isn't the one of the flavor for surviving engine cranking.

**Chris31** · 03-28-2005, 10:37 AM

Originally Posted by lakorai

I would think a large 1 Farad cap or something like that would work because it can hold an emormous amount of electricity - and caps with their very low ESR are designed for "Deep Cycling" which those regulation circuit/engine crank devices with those APC style backUPS style batteries really aren't (regular lead acid isn't designed for deep quick dischage, though I am sure it works fine).

What? another 1 farad capacitor thread? are you serious here? Where did you get all this idea?

Are you aware that your 1 farad capacitor will only last about half a seconds when supplying 5A before your PC crash? hardly any time for cranking is it?

Read here >>>

1 Farad CApacitor Tank?

How about using 10 x 1 farad capacitor? That will cost you half of your car PC

Anyhow theres only one way to find out, just go for it. Look like you already done your research.

And please dont forget to write up a report on your finding and post it here.

Thank you

**shakes** · 03-28-2005, 10:47 AM

Originally Posted by Chris31

What? another 1 farad capacitor thread? are you serious here? Where did you get all this idea?

I was thinking the exact same thing.

lakorai ... the short answer is no.

If you want to survive a crank you either need to build a tank circuit or buy a power supply that is built so it can survive a crank (i.e. carnetix)