Electrickery

I am thinking of removing my alternator from my track mini, mainly so I can put in a front mounted rad in but also might squeeze a few more horses out of it

Question is how long do people think the battery would last? After the winter rewire its only running essentials ie, ignition, fuel pump
and water pump with optional lights, indicators and wiper.

It is only going on track for say max half hour at a time, and I could take a supply of charged batteries to swap over.

Anyone that knows about electrical loads / current -  would that work?

Rally cars can last some think like 3 hours plus depending on if they use lights
But ghost batteries are huge
Doubt a standard battery would last more than 30 mins

As long as you push start the car and don't use the starter you should get an hour out of it. I did just over 40 miles many years ago in my old Cortina when the fan belt broke. That would have been about an hours drive. (no lights...)

Yeah, I would have thought you would get 30 minutes out of it. I have also been looking at small Kubota alternators which might work...

Look at race batteries or even sound system ones Ben sure there long lasting at such low amps. Can be lay flat etc and should last longer and a lot are smaller mine is valley red top but lots out there. Be nice to only carry a couple

Anyone taking into account weather conditions and the adverse effect they have on most car batteries..
If it rains you need wipers and they consume power.
Not a great comparability but I managed about 12 miles on my old nova 1.3 Sr in the rain at about 2000rpm and wipers on bare minimal as I needed them rather than constant. More revs = more drain so faster you go faster you nail the baterry (In theory) so a flat out track would drain faster than a short twisty track, that actual difference is questionable but is worth checking.

You need to work out what the current is and then use this calculator to give you an approxomation of how long you will run for.

http://www.referencedesigner.com/cal/cal_54.php

I don't know all the in's and out's pal, but I know my mates rally escort mk2 has some sort of super small solar powered battery to keep it running. Obviously when the weathers sh*t they're not as good, but could be worth looking into as I'm sure they just simply work on daylight now rather than needing the full power of the sun!

mightydquinn wrote:I don't know all the in's and out's pal, but I know my mates rally escort mk2 has some sort of super small solar powered battery to keep it running. Obviously when the weathers sh*t they're not as good, but could be worth looking into as I'm sure they just simply work on daylight now rather than needing the full power of the sun!

Depends on teh quality of the solar panel and also what its made from, the car trickle chargers that are solar powered may be helpful but I dont know to be honest. Im gonna shut up now as im interested in following this just for being nosy sake.

Yes he need to weigh it really to see
You can get small light race type batteries but without alternator you might only get a few laps
A much bigger capacity battery may weigh more than a battery/alternator setup

Alternator power consumption varies pending on elec load in use so when you not using power hungry stuff such as lights, wipers etc the power it consumes if bearings & pulleys in A1 order would range around 1hp to about 4 possibly for alternator of around 65amp.
If keep alternator you can use a low Ah model battery thus much lighter battery if you not already taken advantage of it.
If decide you really want go no alternator your best taking some readings of current draw with clamp on amp probe. With your basics which I assume includes an elec water pump you could be around 20amps as a safe guesstimate perhaps so a 40Ah battery could push about 2 hours.
You would want a plug socket for quick neat & easy starter battery attachment/charge point & manual isolator for car cell during starting from starter battery.
It is doable & you probably could have enough reserve for a restart if stall & need of some lighting & wipers but not a huge gain for hassle really.
If not done already look at thing like mirrors & other easy aerodynamics & weight saving as that could net a lot more performance edge.

I am right in saying it's ok when it's in tip top condition but charging and running it totally flat it will soon loose charge quicker and last less each time 

What do wrc cars do ?

Deep cycle type battery's can be recharged from flat with no problem but you have often need a bigger battery as it doesn't store as much or have the same cranking power
Some of the race hybrid battery's are fucked if totally flat
Wrc and most other Motorsport now generally use alternators