auxillary power unit

[willib]

i found this last fall , its loaded with RE goodies..

its something that triple A  might carry to start someones car.

it has #4 gauge cables with battery clamps

Two cigarette/auxillary power outlets

The switch is for the light (11ohms ) so it draws about an amp.more on the light later

and a neat little power test thingy , depending on the voltage (loosly the state of charge) the LEDs light up

this is whats inside !

a 12v 17Ah battery

the negatives from the two aux power outlets are connected to a 12V 20 A thermal switch. When the current exceeds 20A it heats up a curved metal thingy and breaks the connection .

although this setup looks kind of cool its not a practical way to hook them up..

because the minus of the two top strings has to connect to the plus of the two bottom strings

this is the way i'm gonna hook it up , just have to drill two holes in another copper busbar for the other string and form the copper connection to the plus and minus of the caps to connect them to the cables..

i decided to go withtwo strings of  six in series , not the best approach , but possibly the safest for the caps..

also i'm gonna use the light to charge the caps up with..

if i take the negative light connection , and bring it out ,and connect it to a positive source , it can charge the caps up safely , i can use the negative cable clamp to complete the circuit..

When the light goes out the caps are almost fully charged , and ready to start a vehicle thats the plan anyway.

[vawtman]

Looks like a fun project Willib

 Did you ever see a cap explode?Just wondering what its like.

 Cool to see how it turns out for ya

[Mary B]

Depends on the cap. Some just open at the top and let all the smoke out. I have seen a few totally grenade and send tinfoil everywhere. In the casino I used to work for we would take a cab and connect it to someones workbench A/C. When they hit the switch it was like a large firecracker going off :-)

[willib]

well its done , and charging up..

it taking forever to charge through the light bulb..

It takes much less time on the excercize bike

Vman years ago i blew a capacitor up , like Mary said the rubber top just blew off..

crap now i'm wondering wether i tightened all the connections , i think i did...

[willib]

after seven mins of fairly agressive pedaling , all LEDs are lit, Voltage is reading 14.5 Volts

[willib]

i didnt notice ANY difference,  in the cranking speed ,between the caps and the battery

I am absolutely amazed

IT WORKED

the Saturn started twice

at first i turned the key , and nothing happened , then i tried again and it started right up

it was recharging at 14.23V between starts

[willib]

I took this shot right after i got in , just after dark ,its reading full charge

its 3:14 AM and it still reads full

about 7 hours later

amazing ..

this thing weighs only 6.1 lbs BTW

[cyplesma]

I dissected a similar unit I had lying around the house. It only had a 7ah battery in it, which was fried. I used it was, and it never took a charge afterward.         I am using the cables with the clamps on it on my 1200 watt inverter. I don't do my re power on a permanent basis just yet, so it really works great. The inverter came with a couple of cables, but I'm using them else where.   I guess it could call it robbing peter to pay paul re.

[willib]

I was walking out my place today with the power pack in hand ,and the guy across the way who was walking back to his place , indicated to me that he needed a

jumpstart.

how could i refuse ?

as we walked over to the parking lot , and i was wondering whether it would work ?

would his battery deplete the Caps before it started , how low was his battery?

i waited till the last possible moment to make the connection , he turned the key and it started , whewww what a relief!!

he thanked me a lot in broken English , i think he promised me his first born or something like that.lol

not bad for 6.1 pounds of equipment.