TheSamba.com :: View topic - How long can I run without charging system for testing?

Wed Oct 24, 2012 3:42 am

Doing a top end rebuild on the project, which is just a pan. Has a 4 wire alternator and would rather not have to deal with the harness yet. Did a couple short rides (couple miles) on just a fully charged battery and it was fine - but wondering how long I can drive without the charging system connected and still supply good power to the ignition system? The battery is only supplying power to the coil. Want to be able to get my rings reasonably seated before I go to much further. Tried a search - no luck.

Thanks!

Wed Oct 24, 2012 5:22 am

You should have 200 miles or so on the battery. Should be plenty of time to make a couple runs to seat the rings.

Wed Oct 24, 2012 5:33 am

Yeah, a healthy battery can power the ignition for hours. I've done just that when my generator brushes failed and I also had the FI pump and ECU to supply.

But now I'd like to see a picture of you driving just the pan around. 8)

Max

Wed Oct 24, 2012 5:42 am

I know you can drive more than 190 miles because I did that for years when I was too broke to buy a new alternator.

Wed Oct 24, 2012 7:03 am

I did drive 200 miles with no altenator. Took the car back the shop, yes 200 miles. Did have a spare deep cycle group 27 battery as well with me.

Wed Oct 24, 2012 8:24 am

it depends on the battery, fully charged means nothing.

is it a 6 yr old no name 400CCA battery ready to need replacing or a 6 month old 750CCA high quality battery.

I did a 4 hour trip on a new battery in my sand rail but it was 875CCA and pushed started it after every stop. when I got home it had just enough juice to start it.

Wed Oct 24, 2012 8:29 am

Max Welton wrote: Yeah, a healthy battery can power the ignition for hours. I've done just that when my generator brushes failed and I also had the FI pump and ECU to supply.

But now I'd like to see a picture of you driving just the pan around. 8)

Max

This was first test drive a week or two ago to make sure everything works on my extended pan and to get the engine warmed up to do leakdown and compression test - which is why I am doing the rebuild LOL

Wed Oct 24, 2012 10:43 am

Bravo! =D>

Max

Wed Oct 24, 2012 2:07 pm

Love the 2x4 steering column support deal thats also serving as psuedo door. All you need.is.is shades and a beanie! Gas can strapped down. Love it.

Wed Oct 24, 2012 11:25 pm

Modern formula vee race cars do not use a charging system at all! scoops direct cooling air, not moving, not cooling. I run a small AGM battery(jump box size) car will start many times and do 2 45 min. races no sweat, I charge over night. but have never run out of juice. First weekend in Apr. will mark 50 years of FV being a class in the SCCA. big race at Roebling Road Raceway, near Savanna, Ga.

Thu Oct 25, 2012 12:51 am

Standard points ignition and coil ~ 4A, small car battery ~ 40Ah = nearly 10h!

Your "Starter type" AGM battery is 17Ah at 20 h rate ~ 3-3.5H

AGM batteries can only tolerate about 200 cylcles, though.

Car battery can keep you going a long time, even with an electronic ignition drawing average 8A you will last more than 4h on a small battery - but always recharge your battery as soon as possible, Lead Acid batteries do not like to be stored in a discharged state.

I can actually provide a lot more technical information on batteries if people are interested, it is a major part of my day job.

Thu Oct 25, 2012 6:35 am

jfats808 wrote: Love the 2x4 steering column support deal thats also serving as psuedo door. All you need.is.is shades and a beanie! Gas can strapped down. Love it.

It's actually a 1x3 and a 1x4 (I think) and a muffler clamp. Ignition "toggle switch" and remote started switch zip tied to the side of the seat. Totally hi-tech :lol:

Hey - last body off build - I sat on a milk crate, used 2 broomsticks to steer and used the same "fuel cell". It works for what I need to do for initial testing. On this build, I stretched the pan 14" and change. Had to lengthen cables, shift rod etc, plus did my first weld in adjusters on the beam. Needed to give it a good blast up and down my lane (mile long dirt road) to verify that everythig worked (it did) and nothing broke (it didn't) and to get engine warm for tests (it failed).

Today doing pistons, cylinder and heads - after welding in another crossmember by the rear tranny mount for rear body support, then serious body work/fabrication. Having a ball!