Advice wanted on battery charging at the track

[StewRat]

For those following the StewRat chronicles you may recall I bought a big battery as part of getting it started for the first time, and the initial charge has sustained all the recent testing and tuning.

But it reminded me today - while driving the car in and out of the lockup for the first time (woohoo!) - that it isn't infinite.

... And that I need to work out what to do at the track - assuming a single battery charge won't last all day? (I know that's a "piece of string" question).

I haven't fitted an alternator as I'd be disconnecting it to race anyway, and without tinware/cooling I assume I wouldn't want to be running the motor between races just to charge the battery.

Can I get something - like a charger but with built in power (presumably another battery) that would keep it topped up between races? Don't want to go as far as a generator, but is this something I can pick up at the likes of machine mart? An initial look doesn't make it clear if any of these work standalone at the track, or if they all need powered to do anything at all.

Or am I approaching this wrong?

BTW, "race support" is a T5 - in case I can run something off that.

Thanks

Stewart

 

[leec]

We have a petrol generator which we then plug a battery charger into (and kettle for tea!)

[Neil Davies]

We used to use a generator too - 2 stroke ones are cheap but 4 stroke ones are quieter and more powerful. I've seen people use an alternator and no fan in the past, just to keep the battery topped up. You could fit some sort of connector to the T5 to plug the car into it, start the van and use that to top the car up?

[modnrod]

A small alternator off a late mini car (like a 3-cyl Daihatsu) on a simple bracket will take less than 2HP, and keep up high stable voltages for everything to run properly.
The extra weight can be saved by not needing a big battery for the whole run and return road.

[DaveN]

If you're going to be doing most of your racing at crail I would run cooling and remove the belt before you run and re fit it for the drive back

[neil68]

That's what I do.  Remove the belt in the staging lanes, then re-install on the return road.

I charge the battery the night before, just to be sure.  The only problem I've had was on one night where I was able to run 12 times down the 1/4-mile, and started doing some hot laps without reinstalling the belt.  Had trouble starting the Beetle on the 12th time.

I have a generator, not sure if that is better than an alternator under these circumstances.

[richie]

A small alternator off a late mini car (like a 3-cyl Daihatsu) on a simple bracket will take less than 2HP, and keep up high stable voltages for everything to run properly.
The extra weight can be saved by not needing a big battery for the whole run and return road.

This or fit stock cooling etc and use stock alternator driving to and from and pull belt off on pass

[dannyboy]

i found the bmd serpentine belt setup i used to run was great .very easy to remove and put back and you only needed a allen key to remove it and refit it

[StewRat]

If you're going to be doing most of your racing at crail I would run cooling and remove the belt before you run and re fit it for the drive back

Dave - interested in the Crail specific reference there (because it is probably where I will spend most time). Whats the Crail factors that lead to that advice? length of return road, queues? It's certainly not the high ambient air temperature 

Stewart

[DaveN]

The reason I suggested that advice was: the length of the return road you drive from the end of the track past the pits ,back to the start line, then back through a car park to get back to the pits!  The queue moves quickly too, most people thought I had broke down when I started pushing my car   It a fun track nothing like santa pod, build the car so its useable there and you will get lots of track time and have a laugh with it.