Tom W

For what Robert is creating, it fits the bill quite well. My comment is meant for the mostly stock, mostly street cars.

Robert Linton

But is there a better/more powerful nanophosphate lithium-ion battery or an even better lighter weight battery?

LA964RS

Robert...left this same Q over on the H20 board....

...the Braille batteries are lead plate...and cheap and the Voltphreaks are lithium-ion and expensive. They both weigh the same at 6 lbs. What's the difference besides price?

Robert Linton

Have been looking at both of them, as well as at A123.

AVoyvoda

Is it worth considering installing two Volts in parallel (not in series)? Entirely un-sure of my electronics, but if that's possible, then you could end up with a 36 amp/hr "battery" vis a 35 amp/hr Optima Red, for less than half the weight (13 lbs vis 33.4 lbs) with enough juice not to need regular external re-charging. Expensive, of course.
Further, being so small, is it worth considering installation elsewhere, say just behind the seats, the rear bulkhead or in the back of the engine bay, enhancing weight distribution?

Indycam

"Tony from Voltphreaks here. Minor correction, the Optima group 34 has 7 times the Ah rating,"
vs
"36 amp/hr "battery" vis a 35 amp/hr Optima Red,"

AVoyvoda

Thanks for the correction. But now I am completely confused:
If the Optima Red has 7 times the ah rating of the Volt, but weighs only 5 times more (i.e. 33.4 lbs vis 6.5 lbs) then where is the high technology advantage of the Voltphreaks (more energy storage per lb etc) ?

Indycam

Getting the cold cranking amps out of a smaller battery .
How small a battery can put out enough cold cranking amps , time after time without being stressed to failure ?
Every battery is a trade off , the Unobtainium battery would be light , high cold cranking amps , deep drain , with a high amp hour rating and cost little . Unfortunately , you need to trade off one attribute for the offers .

These small batteries have one job in life , start the motor one time before being recharged .
If during a race the alt fails , it will not be long before the electrics quit .
On my van and boat , I hope to have a big enough battery bank to get me where I need to go with a failed alt .

Indycam

"But now I am completely confused:"
Its real easy to be completely confused by the subject .
Different tests run by different people to different standards , get all sorts of results , that are then hyped by sales people who don't know the subject . Then add in the blowhard that knows "everything" but gets it all wrong .

vph_tony

The optima only has 7 times the ah rating of the voltphreaks battery under optimal conditions. I'm sure the number is optimistic too. Under, say, a 50amp drain, the optima might only have 3 or 2 times the ah rating of the voltphreaks due to Peukert's effect. If you discharge that Optima Red top completely, it's a doorstop, or will be on it's last legs. The Voltphreaks battery is true "deep cycle" capable, you can leave it empty and charge it back up a week later without any issues.

If you compare the technology, a lithium nano battery has 4x the energy density of a lead-acid's (a 40 pound lead-acid has the same energy as a 10 pound lithium nano). Lithium cobalt/polymer (laptops, ipods, cell phones, etc) can have up to 6x or 8x the energy density of a lead-acid, but of course you wouldn't want to put this in a car (if it catches fire, it can explode, whereas a lead-acid or lithium nano will burn but not explode). Though there are ways to contain the risk, much like we're doing now with gasoline (a HIGHLY explosive energy source).

The power density of lithium nano is MUCH MUCH better than anything else out there, leaving lithium cobalt and lead-acid in the dust. Power density is how much power (watts x volts) can be put out per unit of weight.

The volume density of lithium is much better than lead-acid's also, but volume isn't usually that much of a concern as weight and power in automotive applications.

Anyways, nano-lithium is going to be powering the future of hybrids and electric cars (PHEV and pure BEVs).

- Tony (voltphreaks.com)

AVoyvoda

Thanks Tony. Your key argument is that “The optima only has 7 times the ah rating of the voltphreaks battery under optimal conditions”. You then continue that in real life “the Optima might only have 3 or 2 times the ah rating of the voltphreaks”.

We must consider that for marketing reasons the Volt people may (probably) state output under optimal conditions as well. In real life then, the Volt may have a lower ah rating too.

You are probably right in your 2 or 3 to 1 assertion, but do you have any data to support your case?

Robert Linton

In short, can the Voltphreaks battery or the Tek Battery be used for a daily driver?

Indycam

"Measurement of Amp-hours remaining is a complex operation requiring computation of an exponential equation discovered by Peukert in 1897."
http://www.smartgauge.co.uk/peukert2.html

“the (red top) Optima might only have 3 or 2 times the ah rating of the voltphreaks”. if you stop the discharge of the optima at some point so as not to deeply drain it .
The yellow/blue top is a different story .

Geoffrey

Robert, I have an Oddesy PC680 in my race car and I consider that a minimum. If it is cold out and the car doesn't start in the first 7-10 seconds of cranking, the battery is dead.

I hope this helps.

vph_tony

Yes the Voltphreaks battery of course is rated optimally too. It's capacity doesn't drop as much under higher current draw. During testing we've gotten 6.5Ah at 5A:



No data on that Odyssey battery, but another thing to keep in mind is that as a long term energy storage device, lead-acids are good since when it's slowly being discharged (in a parked car for example), it will get close to it's rated Ah rating.