new idea, i think

**CornToeGoblin** · 09-01-2005, 12:22 AM

ok i'm pretty sure this might have come up before but i wasn't clever enough to use the correct search keywords and didn't find anything, so here it goes

I was thinking today that maybe it'd be possible to run a 2 battery setup but only using one battery for the carputer. but wait! if you thinking WOW what a newb

and

better next time, keep reading

.

instead of hooking the 2 batteries to the carputer and having a switch between the two, have only one connected to the computer (which is a deep cycle) and have the PSU connected straight to the alternator and then having a switch or a relay based on ignition status. this would be useful for 2 reasons

no drain on the starter battery so you always have a good charged battery so your not left stranded on a good night of partying
save yourself gas not having to idle the car with the puter on

i'm not sure what kind of problems you might have with connecting straight to an alternator like spikes in energy production, because i'm pretty sure it doesn't produce 12V constant. a psu might be able to play with the current like opus's do. but based off what an alternator site says it might be possible.

Originally Posted by http://members.1stconnect.com/anozira/SiteTops/energy/Alternator/alternator.htm

"When modified, auto alternators can provide variable direct current at 0 to 120 volts for battery charging, hot charging, light arc welding, or for running AC-DC appliances and lights."

tell me what you guys think

**wizardPC** · 09-01-2005, 12:35 AM

when you say PSU, you do mean power supply, right? cause im confused about how you would connect a carputer to the battery, but the power supply to the alternator....

And a dual battery setup does exactly what you are proposing--you hook up the carputer to the second battery and it only drains that one. The batteries are ISOLATED. When you turn the car on, the alternator powers the carputer and at the same time charges both batters.

**Bugbyte** · 09-01-2005, 12:45 AM

I think Wizard is right. You're talking about something called a battery isolator.

**CornToeGoblin** · 09-01-2005, 01:05 AM

yeah you guys got it i just didn't know what the name of this type of thing was called, thanks!

**CornToeGoblin** · 09-01-2005, 02:46 AM

I just read over that site and it doesn't really seem to be the thing i was looking for, although it does serve the same purpose. What i'm talking about is 2 battery setup, but instead of overcomplicating things with solenoids and diodes you could use a relay that monitors ignition status and has the alternator connected (not going through the battery) to it and the dedicated battery also connected to it. Once the ignition goes cold then the dedicated battery powers the PSU (power supply unit) until the battery is dead since you'll have to be recharging it anyways. Once the ignition goes hot then power the PSU with the alternator. It doesn't need to control the voltage of the current because the PSU will be doing that ex: OPUS or m1-atx

all you would need in the end is a switch that controls if you want the computer on or not in either ignition status.

**84RegalRider** · 09-01-2005, 02:57 AM

Originally Posted by Bugbyte

I think Wizard is right. You're talking about something called a battery isolator.

yea that is it.

Why is this not in newbie forum???

**CornToeGoblin** · 09-01-2005, 03:02 AM

Originally Posted by 84RegalRider

yea that is it.

Why is this not in newbie forum???

because this isn't based on switches like it has it on the bcae site and its a hardware idea and i wasn't asking for information i was asking for feedback on an idea that just sparked out of nowhere.

**Jeeve5** · 09-01-2005, 03:09 AM

Originally Posted by CornToeGoblin

You setup has a major flaw IMO and that is if the Relay switches from teh Deep Cycle Battery to the Alternator you PSU is gonna loose power for a very short period of time, but it is gonna be enough to shut it off and your PC will be off :P

Correct me if I am wrong

**CornToeGoblin** · 09-01-2005, 03:11 AM

Originally Posted by Jeeve5

You setup has a major flaw IMO and that is if the Relay switches from teh Deep Cycle Battery to the Alternator you PSU is gonna loose power for a very short period of time, but it is gonna be enough to shut it off and your PC will be off :P

Correct me if I am wrong

i agree with you and that could probably be fixed by adding an adequately sized capacitor that is charged when either of the power sources is being used.

**Jeeve5** · 09-01-2005, 03:16 AM

Originally Posted by CornToeGoblin

i agree with you and that could probably be fixed by adding an adequately sized capacitor that is charged when either of the power sources is being used.

Yepp, AFAIK a cheapass 1F Cap from eBay would do the trick. However I highly suggest that you look into something called a tank circuit. I use it in my CarPC setup and it works like a charm and basically does the same as you suggested just better IMO