Putting a battery on a electronic Switch

[Bump4life]

Put a clamp on your starter and see...

i could. i just looked up my starter and got the ratings. i was being lazy. worst case scenario if its -40 i drop to 8 volts the most it will draw is 475 amps

so i am going to get this guy i believe tony carrys the same ones.

its 200 continous 600 peak. will do plenty for me since on most days my starter would pull around 150-200. i only got a 4 banger. but if needed it will do that job. but i dont plan on being in -40 with this car lol.

http://www.amazon.com/WHITE-RODGERS-586-902-CONTACTOR-SPST-NO/dp/B00DE3HY4K

[Bump4life]

for refrence for anyone who views this.

i ended up getting this solenoid.

http://www.mouser.com/ProductDetail/White-Rodgers/586-108111/?qs=%2fha2pyFaduipp3hvpSX7Xkq9Uo0lBtnYgKmPlaaShYbWeogZs1uAIg%3d%3d

[Wicks]

I was thinking about doing something similar with my setup.

How are you going to keep the battery charged?

Just pop the switch every once and a while?

I was looking into making an automated switch that connected the battery when the car was running and when the engine was turning over, but disconnected when the key was off.

A starter motor probably has a MASSIVE inrush current, but only for 1/2 a second or so.

So as long as your continuous rating can handle it then you should be fine.

Keep in mind if your caps are empty and you pop over that solenoid, you're probly going to get a pretty decent arc which will degrade the solenoid over time.

Some fancier solenoids might have an internal gas which helps eliminate the arcing.

If its more for an emergency issue then you might be OK with sacrificing one here and there if needed.

May want to do a test run on the system to make sure the battery has enough capacity to power the caps and turn the engine.

I would think so, but its always good to check beforehand.

[Bump4life]

I was thinking about doing something similar with my setup.

How are you going to keep the battery charged?

Just pop the switch every once and a while?

I was looking into making an automated switch that connected the battery when the car was running and when the engine was turning over, but disconnected when the key was off.

A starter motor probably has a MASSIVE inrush current, but only for 1/2 a second or so.

So as long as your continuous rating can handle it then you should be fine.

Keep in mind if your caps are empty and you pop over that solenoid, you're probly going to get a pretty decent arc which will degrade the solenoid over time.

Some fancier solenoids might have an internal gas which helps eliminate the arcing.

If its more for an emergency issue then you might be OK with sacrificing one here and there if needed.

May want to do a test run on the system to make sure the battery has enough capacity to power the caps and turn the engine.

I would think so, but its always good to check beforehand.

lol so heres the story if you missed it. I was headed down to slamology. i was an idiot and wired my alternator regulator wrong. after a while it failed. so im an hour from indianapolis. screwed because caps onloy get you 4 miles at most down the road before they need to be recharged. (14 volts down to 11 volts).

so i ended up buying a group 51 battery from meijer and it got us the hour we needed. So i have no doubt in my mind the xs power d5100 can supply the car for at least an hour or more before being discharged.

after thinking about it again, the caps will always be connected regardless if the battery is connected or not, so the only thing i need to worry about is running the car and the lights. i can start the car on the caps as long as the starter solenoid will engage. the caps will provide all the amperage ill ever need. i dont even need to have the battery connected to start the car. the only thing is connecting the batt to the caps.

i have to be sure that in an emergency i dont drain caps to low to where the battery wouldnt like it. the minute i hit 13 volts in an emergency i would engage the solenoid and the battery would connect to the caps without an arc since that is battery resting adn they would be at same potential.

battery will be charged on a charger initially. it will sit for months just fine. id connect to car every now and then to give it some juice. ill be sure to run it through a cycle to train it as well. and

you would not want the batt connected with car on. only time youd want bat is if car is left for a long time (over 6 days) , so the batt accounts for cap leakage.

caps are great as long as you have an alternator.and yes a gas in the solenoid would be awesome but then the expense goes up and as long as im smart i shouldnt be arcing anyway.

[Wicks]

Yeah that's right, the caps wont fully discharge, only down where the car is dead.

I did hear your story. That sucks, glad all was well.

I have a similar story about being stuck in the middle of South Dakota with a dead alternator and needing three batteries to get my home....

So with those caps not fully discharged then the arc won't be as bad.

Sounds like a pretty good backup idea.

[Bump4life]

Yeah that's right, the caps wont fully discharge, only down where the car is dead.

I did hear your story. That sucks, glad all was well.

I have a similar story about being stuck in the middle of South Dakota with a dead alternator and needing three batteries to get my home....

So with those caps not fully discharged then the arc won't be as bad.

Sounds like a pretty good backup idea.

i think i remember your story. or someone elses.

either way, batteries have their place. and it doesnt belong in my 15.5 volt charging system

only thing i worry about now are all my other relays and starter solenoids.

wicks, do you

or anyone else,

know if manufacturers use 12 volt or 15 volt or higher relays and solenoids in cars? with running higher voltage i worry about popping them.

[Wicks]

Yeah that's right, the caps wont fully discharge, only down where the car is dead.

I did hear your story. That sucks, glad all was well.

I have a similar story about being stuck in the middle of South Dakota with a dead alternator and needing three batteries to get my home....

So with those caps not fully discharged then the arc won't be as bad.

Sounds like a pretty good backup idea.

i think i remember your story. or someone elses.

either way, batteries have their place. and it doesnt belong in my 15.5 volt charging system

only thing i worry about now are all my other relays and starter solenoids.

wicks, do you

or anyone else,

know if manufacturers use 12 volt or 15 volt or higher relays and solenoids in cars? with running higher voltage i worry about popping them.

Well is common practice for (quality) manufacturers to de-rate a component by half for good reliability.

Therefore if you need an application in a 12V circuit, the designers will use parts rated to 25V.

Look in the AmpGuts section. You'll see that a lot of the DC input caps in amplifiers are rated at 25V, or at least they should be.

Relays and solenoids just use a coil to move the switch.

I highly doubt a few extra volts will hurt one of those coils.

Some of the solenoids come with spec sheets that list the coil resistance.

You could do the math and figure out how much more power you'd be giving the coil and see if it might be an issue.

[Bump4life]

cool. yea i was doing the math with various solenoid and relay impedences and the most i got was .2 amps more. over time that may be an issue. but as long as I have thsi car I dont see a problem.

i was curious because I know if you run a solenoid rated at 24 volts lets say. if you only run 12 votls to it, isnt the electromechanical connection weaker?

[Wicks]

cool. yea i was doing the math with various solenoid and relay impedences and the most i got was .2 amps more. over time that may be an issue. but as long as I have thsi car I dont see a problem.

i was curious because I know if you run a solenoid rated at 24 volts lets say. if you only run 12 votls to it, isnt the electromechanical connection weaker?

If a slight overvoltage bothers you, then you can always grab a small 12V regulator.

Yep, you don't want to run lower voltage to a solenoid. Might weaken the electrical connection or not allow it to switch over or hold in place.

[Bump4life]

cool. yea i was doing the math with various solenoid and relay impedences and the most i got was .2 amps more. over time that may be an issue. but as long as I have thsi car I dont see a problem.

i was curious because I know if you run a solenoid rated at 24 volts lets say. if you only run 12 votls to it, isnt the electromechanical connection weaker?

If a slight overvoltage bothers you, then you can always grab a small 12V regulator.

Yep, you don't want to run lower voltage to a solenoid. Might weaken the electrical connection or not allow it to switch over or hold in place.

i thought about that too. but then i might as well isolate my damn system lol. im sure it will be fine. it has run this high for 6 + months now.