"wet" or "dry" battery for racing

[C.U.Motorsport]

is it better to use a dedicated racing "dry" battery such as the Varley Red Top or will a normal "wet" car battery do???

[R59]

All depends on what you're racing. ie: what are you trying to start, how often will you need to start it (ie: in some regulations they state that you must be able to repeatedly start the engine).

And how much weight you want to save. Do you need to save it? Could the battery form part of your ballast if you have to add weight?

There are quite a few nice SLA's on the market now (sealed lead acid - or GEL batteries), which will supply a good cranking current. The benefit of these is that they can be mounted anyway up, so find a gap, and put your battery in there.

I use a wet "063" battery to run my V8 Chevy powered Astra. It has plenty of capacity for what I want, it's not too heavy, but I need cranking current to make sure. What's more, it's cheaper than chips.

On a single seater (FF1600 or similar), I'd be looking at a small SLA (about 17-25Ah would do), with a start battery socket.

It's one of those "how long is a piece of string" questions.

Like - should I fit an alternator on my racing car (which has been well and truly thrashed to death on this forum elsewhere).

Rob.

[Notso Swift]

Originally Posted by racing59

It's one of those "how long is a piece of string" questions.

Or when the sizes start to get up, how deep are your pockets?:lol:

Yes they are better (IMHO), are they worth the extra, only you can answer.

[C.U.Motorsport]

So you DO get better performance from a varley but it comes at a price. Ok cheers

[dtype38]

If you want most "bang for your bucks" then I can recommend the Red Top 15. If you check the specs this gives a much better cranking output for its weight than the rest of the range. It's constructed differently and the downside is that it has less reseve than the others. That said I've used the same one on my big Jag engine for the last three years without any repeat starting problems :-)

[johnny yuma]

Slightly related topic, with remote battery location what is a rule of thumb on maximum length of + lead before current struggles to get to the starter ? Any other advice[3 litre sedan],wet cell battery.

[Notso Swift]

Doesn't it change with the thickness of the cable?
thiner cable = less amps due to more resistance (as shown by heat).
I don't know of voltage drop being much of an issue with the couple of meters we are talking about. (but IIRC) bigger cable has a grater voltage drop)

[1200Datto27]

The location of the (-) connection and lenght of that cable makes a difference as well.

[robm]

Hi, with regards to the above query there are significant advantages of using 'dry' batteries. Firstly safety, a dry battery uses AGM technology (absorbed glass mat) this means the inside of the battery is completely dry as the electrolyte is soaked up into specialist glass matting. This means that if the battery is inverted or punctured during an accident their is no risk of harmful acid leaking which can cause serious injury and damage. Do not confuse dry batteries with Gel types. As the name suggests these have a semi liquid gel interior. This can still leak if puctured allbeit at a slower rate than 'wet' types. However as the gel battery is used and warms up the gel thins so can leak at a faster rate if punctured then. A Varley Red Top also has a fire resistant casing.

Secondly power to weight ratio. The cranking power of dry batteries allow you to use an item alot smaller and lighter than a wet alternative.

Location is also an issue. The safety qualities of the dry battery allow you to install it in any orientation (nothing wiill leak out) allowing the weight to be placed in a specific place for balance or space saving requirements.

Beware not all dry batteries are the same!!! the most well known of the dry cell racing batteries are the Varley Red top. These are the only ones that use 19 plate lead technology in each cell, offering the maximum power output per size and fast recovery and charge rate. There are dry cell batteries out there being sold as racing batteries in the same dimensions as the varley range and some even use names such as RT15, 30 etc. They are not racing batteries but were designed for static stand alone applications such as telecoms use etc. They have less lead plates per cell providing upto 30% less power and do not carry a motorsport guarantee. there are also more and more clone products coming from the far east. If it doesnt say Varley on the label and DMS technologies it isnt a Varley!

Yes Varley batteries are expensive but many people over specify what they really need. A red Top 15 for instance can power a Formula Ford 1600 on a full test day without top up charges or a charge system (alternator) on the car. For cars that do have a charge system the Red Top 15 can do an amazing job for such a small item as used in Formula Nippon, A1gp, Radicals, Formula BMW etc. So you dont necessarily need the Red Top 30 or 40 that many people think.

Maintenance: With dry cell batteries they will last a long time if looked after properly, always make sure that they are left fully charged. A new Red Top if charged fully after use will been fine for a year if disconected. Do not leave them without charge in (this is a common mistake made by people used to older battery technologies).

Installation: Even though a Varley Red top has a motorsport application warranty, it will need to be installed correctly to avoid excess shock and vibration. Always if possible use absorbant material around the battery. Foam underlay or Tool box tray foam is ideal and do not strap too tightly.

I hope this information helps. Rob M

[tzei]

I know two occasions that new red tops have given up the task. Panasonics have lasted.

[robm]

If that happens and it is very rare, DMS will take the battery back, and analize (with a dedicated research and development team) what has caused the failure, and if it is product failure rather than installation error or missuse a replacement will be issued. For istance, at the first UK round of A1gp at Brands hatch there were some battery issues with an installation problem, but with DMS working with Lola and the teams the product has now worked faultlessly.

Happy racing!

[norman-normal]

I have been running one in my daily driver (Toyota Supra Turbo 3L, power everything) for more than a year now. It is an Odyssey PC680MJT: 7in L, 3 1/4 W,6-5/8 H Weight: 15.4 pounds. It replaced a 40+ pound wet bat that was located in the worst possible place, high over the drivers ft wheel. I located it flat on its side on the floor behind the passenger seat. I used 2ga cable with 6 strong ground connections and a battery cut-off switch near the battery that I can operate with out attracting attention.
I have had no problems, it has much cranking power. Cost $100. inc shipping

IMHO any time you can lose 24# gain a better weight distribution, its a definite win.