lets talk about racing batteries

andy robinson · 7 Jul 2010, 21:26 (Ref:2723251)

My 7 ltr falcon has a fancy (fresh rebuilt)tilton starter motor & a new red top 40 & starts car no problem when battery is 100%
When racing, alternator seems to charging ok ie 13v, but battery is well low & struggles to restart car after race, but as soon as i plug boost pack its spins over fast, proving the alternator is not charging the battery enough which would suggest just put a more powerful alternator on but ive had this problem before on other race cars with red top batteries
any views ? or experiences ? (& yes ive have cleaned/checked earths & connections)
im thinking of trying a exide 900dc
http://www.demon-tweeks.co.uk/Motors...y/1447/0/14641

GORDON STREETER · 7 Jul 2010, 22:45 (Ref:2723289)

I don't know how accurate your voltmeter is but it should be charging between 13,8 -14.8 volts with everything on. You don't necessarily need a bigger output alternator, just get your own one checked out first. That 1 volt makes all the difference !

Notso Swift · 8 Jul 2010, 01:31 (Ref:2723328)

Absolutely, 13 is just not enough these days

JimW · 8 Jul 2010, 09:12 (Ref:2723402)

Voltage is by no means the only thing you need to measure to get an idea of what is going wrong. Yes, 13 is too low.

Have a look at the charging current your alternator is actually delivering to the battery after starting the engine.

Then see what the battery voltage drops to when not on charge and supplying a normal load (not on starting).

Then get someone with the right equipment to test the battery properly.

I see from the Varley site that the 40 is recommended for engines up to 6 litres.

Regards

Jim

R59 · 9 Jul 2010, 18:32 (Ref:2724160)

You should also check earthing, make sure that the alternator has a really good earth, or whatever it does isn't going into the battery! The wire should be as thick as the wire feeding the battery

A good alternator will/should charge at between 14.2 and 14.4V.

I use a convetional 44AH battery with my Belmont as weight isn't an issue, if anything, having a slightly heavier battery on the passenger side is a bonus!!
As long as it's well charged before I start (it's pretty tired!), it'll always fire up my high compression 403ci of Chevy, even if you think it won't when it's going wha.....wha....wha..wha vroom!

On the ASCAR I have a 25Ah Varley, and that will start it no matter what.

andy robinson · 30 Aug 2010, 22:41 (Ref:2752486)

fitted a exide 900dc, £144 of ebay
almost give the starter a heart attack.....
use to have a varley red top 40 which in theroy should do the job but even with igd retard on used to fight starter motor badly,
starter now spins over like it just had a can of red bull
expensive yes but worth it
& car restarted no probelm @ end of race

terence · 2 Sep 2010, 05:13 (Ref:2753483)

You lot really havn't shopped around have you? £144! Take a long look at the batteries from Mobility Scooters

Could have saved £111.00

GORDON STREETER · 2 Sep 2010, 06:55 (Ref:2753496)

Quote:

Originally Posted by terence bower

You lot really havn't shopped around have you? £144! Take a long look at the batteries from Mobility Scooters

Could have saved £111.00

Or telephone exchange standby batteries that are changed before they need to be. Its who you know in life

andy robinson · 2 Sep 2010, 23:16 (Ref:2753867)

oh bugger, & i was all happy with it compared to the tweeks price, you've just weed on my chips

GORDON STREETER · 8 Sep 2010, 13:40 (Ref:2756174)

Sorry Andy we have all learnt the hard way. I have a 10 year old ex telephone gel battery that will still jump start a tractor !

RF_Racer · 8 Sep 2010, 15:52 (Ref:2756233)

Any recommendations for a jump battery pack? The ones on DT website are all around £200. I have seen some cheaper ones by Sealey etc are they the same with just Anderson plug?

Corolla52 · 8 Sep 2010, 22:33 (Ref:2756458)

Quote:

Originally Posted by RF_Racer

Any recommendations for a jump battery pack? The ones on DT website are all around £200. I have seen some cheaper ones by Sealey etc are they the same with just Anderson plug?

I just bought a cheaper battery pack and fitted a 175 amp Anderson plug to it and it works fine.

R59 · 9 Sep 2010, 21:50 (Ref:2757004)

Quote:

Originally Posted by Corolla52

I just bought a cheaper battery pack and fitted a 175 amp Anderson plug to it and it works fine.

Me too. I used 320A plugs on mine, and that allows me to use the pack to either plug into the car, or plug into the jump leads for use on anything else.

My Sealey pack is the RS1, had it a few years. Starts everything from lawn mowers to tractors!

andy robinson · 13 Sep 2010, 06:58 (Ref:2758523)

Ive got a snap on boost pack which I use every day for work (really good-will start loads of cars before going flat)then put the anderson lead on for when i go racing, job done

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Go talk racing	peckstar	Australasian Touring Cars.	9	24 Nov 2005 21:58
The goldern era, lets talk about 1996?	luke	ChampCar World Series	50	17 Dec 2004 16:20
Lets talk about TRAC	Baritone24	NASCAR & Stock Car Racing	17	5 Mar 2004 15:16
Lets talk about Patrick Head...	Sodemo	Formula One	31	26 Nov 2003 21:59