420A Smallest Battery Size To Crank 420a

[BLACK'98DSM]

Hey guys, quick question for you. I'm wanting to add a new battery to my stock pile of parts in preparation for Spring. I'm looking to downsize a significant amount. My current battery is huge, putting out 850 CCA to run the sound system I had. The sound system is now removed from the car and I just have a radio unit and basic speakers.

Anyway, I'm curious how small I can go with the battery. Finding somewhere to mount a small battery is no issue at all. I'm just wondering how much juice the starter actually needs to crank the 420a. Keep in mind it may need a little more power from higher compression, but shouldn't affect much. I was thinking something along the lines of 400 CCA? Or maybe even 350?

I guess worst case scenario, if whatever I buy won't work I'll just trade it in for a size bigger. Just trying to at least get a general idea of where to start. Some of my buddies running 1.8's with no alternators are using snowmobile batteries. But I'm still running the alternator and 2.0

 

[dustyboner]

stock is 525

 

[BLACK'98DSM]

Most local places have a 30 day trade in policy, so I'll need to wait until closer to Spring. If I bought it now I'd be stuck with whatever I bought and have no room for experimenting. I'll be sure to update the thread with whatever I end up using. I'm going to start with the smallest automotive battery possible and work my way up from there if it doesn't work.

 

[97egl]

Most local places have a 30 day trade in policy, so I'll need to wait until closer to Spring. If I bought it now I'd be stuck with whatever I bought and have no room for experimenting. I'll be sure to update the thread with whatever I end up using. I'm going to start with the smallest automotive battery possible and work my way up from there if it doesn't work.

You may try a lawnmower battery. I used one for my celica in high school cuz I couldn't afford a car battery. As long as the car doesnt crank a bit before it starts they seem to work pretty good. If the car has a long cranking period before it starts itll draw the battery down.

 

[BLACK'98DSM]

You may try a lawnmower battery. I used one for my celica in high school cuz I couldn't afford a car battery. As long as the car doesnt crank a bit before it starts they seem to work pretty good. If the car has a long cranking period before it starts itll draw the battery down.

It starts right up in just a few rotations. Actually quicker than most if the cars I've owned. Were you charging the battery with the alternator? Would it not damage the battery?

 

[97egl]

Yes I was charging the battery with the alternator. Lawn mower battery is a 12v lead acid battery same as a car battery just smaller so you won't hurt the battery by charging it with the alternator. I only ran the car that way for a year before I wrecked it so I couldn't say for sure if cranking a 4 cylinder hurt the battery but lawnmower batteries were around 15 bucks back then and a real battery was 70ish so it worked out good for me.