Lightweight Battery

[jonb_5 6]

Hi

 

I am going to replace the battery in the 205 and so would like a much smaller and lighter weight battery.

 

Its not going to be powering much, a couple of gauges and ecu, injectors etc.

 

I am going to remove the alternator and just charge between races. I have searched but technology moved on so quickly.

 

Other than the top brands, Odyssey, power vamp etc is there a cheaper alternative that is still going to start the car.

 

The lighter the better really, budget from £50 - £100.

 

Thanks

 

Jon

[Tom Fenton 1,542]

I have an Odyssey, I'm pleased with it. They have come down a lot, a few years ago the only option was a Varley red top, they really were expensive.

[swordfish210 20]

I have an Odyssey, I'm pleased with it. They have come down a lot, a few years ago the only option was a Varley red top, they really were expensive.

 

Odyssey are Varely essentially. Bit of an odd situation but they were building the batterys for Varley and when Varley went bust Odyssey made them for themselvs. Least thats how i think it went down

[harryskid 193]

Demon Tweeks stock Varley Red tops and also Odyssey ! The Odyssey appears to be the cheaper option

[SimonJ 2]

I'm thinking of one of these for my hillclimb car. What model number (amps?) does anyone recommend?

[Paul_13 212 1 Cars]

Surely by removing alternator its going to die pretty quick after starting it? Starting takes a large amount of voltage.

When I had a dodgy alternator which wasn't charging and fully charged battery it wouldn't accelerate at all, the cars going to drain off a lot more than you realise. Ecu, fuelpump, spark plugs(coil/s), all need a decent 12v + feed or they're not going to work?!

 

Why not just get a Denso alternator (can't remember what off), a lot smaller and lighter than oe.

Edited September 30, 2011 by Paul_13

[vern 0]

I use an MX5 gel style battery, is about £90, is smaller and lighter than standard battery yet gives more cranking amps.

http://www.mx5parts.co.uk/product_info.php/products_id/635

[tri_longer 25]

Have a look at Powervamp, same as Odyssey but little bit cheaper.

[wardy18 33 1 Cars]

I ran an Oddessey Extreme 45 with the new engine for the last few events and its a 12.5kg battery but still even on a full charge only had enough juice to turn the engine over for maybe 10 seconds and would be no use in startin the car throughout the day, engine is a 2.3 with a 12.5:1 CR ratio.

 

To start the car now i have a jump battery with jump plugs in the pits with me and at the end of the hillclimb/sprint to restart.

 

So i am now going to save a shed load of weight and replace my Oddessey batt with a 4.9kg Varley Red Top 20, it has no chance of ever starting the car but the way i see it its just a power cell to hold charge from the alternator while im running.

 

My advice is (strongly) do not remove the alternator, i did this when i started racing and a full 2 events i couldnt work out why the car would die half way up the hillclimb on every run at the same place, i checked all wiring, fuel surging etc etc and it turned out that the battery was dieing but then when i would plug in my jump pack at the bottom it would give it a little charge to get back half way up the hill teh next run.

 

If you wanting weight saving by removing the alternator then do what i did, fit a Nippon Denso alternator from a tractor or a <1000cc car (mine was from a Daihatsu Move 887cc)(£25 from ebay) then got a smaller crank pullley for it and larger alternator pulley to overdrive it.

 

Really dont drop the alternator, just creates more issues and keeps you on egde wondering if there is enough charge to get you through the day.

 

Hope this was some help, i have experienced many situations with batteries and alternators and im finally very happy with my current set up.

 

Simon

[jonb_5 6]

Many thanks for the replies, advice taken r.e. alternator I will leave it in.

 

My boss at work runs a Nova GTE on hill climbs with no alternator and just charges up before each event and it is fine but obviously this is a different car so I will leave mine in.

 

Thanks

 

Jon

[wardy18 33 1 Cars]

What battery does he run??

 

If your happy to run the weight of a normal deep cycle car battery (one that can loose complete charge and not bugger up) then you can get away with no alternator, but that's alot of weight to carry!!

[Mark Greenwood 0]

Yeah a NOVA GTE is on carbs, so has not got injection electronics to run...

 

Would last allot longer than a 205 on batt alone..

 

Strictly speaking the injection system on a the 205 is primitive to say the least, and when it was designed, power saving was the last thing on their minds..

[Birdie 0]

I've just bought a powervamp pvr25, very good power to weight ratio imo.

 

http://www.powervampracing.com/detail.asp?ID=23

[tri_longer 25]

Same one I have, though I am still on standard alterntor. I may take a leave out of Simon Wards project and run a small Denso one I think.

[Rippthrough 98]

I ran an Oddessey Extreme 45 with the new engine for the last few events and its a 12.5kg battery but still even on a full charge only had enough juice to turn the engine over for maybe 10 seconds and would be no use in startin the car throughout the day, engine is a 2.3 with a 12.5:1 CR ratio.

 

Then I'd say there's something wrong with your battery or excessive resistance in your wiring, we use a 40 unit on the safari cars and it will quite happily turn over a 3.7 V6 in 15 second on/off bursts for about 5 minutes, even when the cars have been in parce ferme overnight in -20*c temperatures and they're getting cranked over to build oil pressure it copes just fine, got one on the latest 5.0L V10 too, never struggles.

Edited October 12, 2011 by Rippthrough

[wardy18 33 1 Cars]

Oh that's not good then, how do you check the resistance in the wiring??

 

It has been through a crash and dis-logged itself from the mount in the rear of the car and landed in the passenger footwell, it now leaks battery acid ever so slightly so isn't in the best condition!

[Rippthrough 98]

That might explain it

 

Bent the plates at a guess?

[petert 587]

Back in the old days, batteries were only used for starting as carbs and magneto distributors were the norm. But advancements in management and spark requires constant 13.8V, as injector opening time/dead time changes with decreasing voltage. Some ECU's have a look up table, but it needs to be calibrated for the injector being used. If weight is an issue, run a light weight alternator, an 18Ah gell cell and a larger battery connected in parallel by an Anderson plug to start it in the pits.

[wardy18 33 1 Cars]

Does it have to be a 18Ah battery?

 

The Varley Red Top 20 i am going to use is only 13Ah and i run a 40amp Nippon Denso Alternator which gives a constant voltage over 13.8v whilst running and started with the jump battery every time.

 

Even the 25 range is only 16Ah

Edited October 13, 2011 by wardy18

[petert 587]

No, it could be less. Just don't ask it to start the car if you stall it. A tow back to the pits is always embarrassing.

[wardy18 33 1 Cars]

Ok thats a releif, im used to it not starting the car anyways so if i stall or have to shut down i just jump out the car and go grab my jump battery