Voltphreaks Lithium Battery

[BrewRifle]

Originally Posted by whats77inaname

Specifically says in the instruction manual not to use below 14F.

http://batterytender.com/includes/la...ery_Manual.pdf

However, in the product description, it says the operating range is 0F - 140F.
http://batterytender.com/lithium-iro...-eq-26-35.html

Given I'm in Tx and and it doesn't get that cold here, I'm good with it. If and when by some slim chance it *does* ever get that cold, I can drive the VX



Interesting question, to which I don't have an answer.



According the manual:
"Standard lead-acid chargers may be used, as long as they do not exceed 14.8Volts during charging.
c) Maximum charge rate is 10Amps.
d) It is strongly recommended the use of a lithium specific charger such as the units in the Battery Tender® Lithium Charger series."

The Li specific charger is only $30 on Amazon (P/N 022-0198LI).

Let me know if you end up changing out your battery as I'd like to see the finished product and perhaps even go down the same route to save some weight.

[whats77inaname]

Originally Posted by BrewRifle

Let me know if you end up changing out your battery as I'd like to see the finished product and perhaps even go down the same route to save some weight.

Oh, I'm *definitely* going to do it, the only (1st world) problem I have is that I replaced the battery in the car last year w/the comparable DieHard, and I replaced the battery in the truck 2 months ago w/an Optima Yellowtop :-\ Given that, it becomes hard to rationalize the expenditure in the near future.

But I'm all about saving some weight. I know I've added some things that have added 20lbs or so, and it would be nice to get some of that back, b/c we all know the E9X platform carries quite a bit of heft *lol*. I'm loathe to want to lose any of the luxury of the car at the expense of trimming weight, but this seems like a good trade-off.

[italyix]

Originally Posted by BrewRifle

How did you end up securing yours?

I had the shop fab a simple bracket that bolts it down. At 7 lbs, there is not much to bolt down and the battery does not move at all.

For everyone that is saying baller status or its soo expensive, may I remind everyone that the you are saving 53-55lbs (depending on which unit) for the price of a set of wheels. How much is a full Ti exhaust again? And how much weight do you save per $? Thats right...

And the weight loss is taken away from one of the worst places (besides the roof) to have weight in.

I did this mod and the iND CF roof and the difference is extremely noticeable. Sure $1k for a battery sounds ridiculous but I think we are attributing the price to such a small object that we cannot quantify the purchase. So expensive for a small item?

To everyone out there thinking of doing this, GO FOR IT! Did I mention the battery is also upgradeable and rebuildable?

As far as trickle charges go, Voltphreaks sells one specifically tailored to the battery. I bought one as well in case I needed it.

[Hujan]

Originally Posted by italyix

I had the shop fab a simple bracket that bolts it down. At 7 lbs, there is not much to bolt down and the battery does not move at all.

For everyone that is saying baller status or its soo expensive, may I remind everyone that the you are saving 53-55lbs (depending on which unit) for the price of a set of wheels. How much is a full Ti exhaust again? And how much weight do you save per $? Thats right...

And the weight loss is taken away from one of the worst places (besides the roof) to have weight in.

I did this mod and the iND CF roof and the difference is extremely noticeable. Sure $1k for a battery sounds ridiculous but I think we are attributing the price to such a small object that we cannot quantify the purchase. So expensive for a small item?

To everyone out there thinking of doing this, GO FOR IT! Did I mention the battery is also upgradeable and rebuildable?

As far as trickle charges go, Voltphreaks sells one specifically tailored to the battery. I bought one as well in case I needed it.

I agree with this sentiment. Challenge is asking $2000 for a CF trunk that sales 20 lbs. This is half that for something that saves more than double the weight in the exact same place on the car.

So here's the questions:

1) Would anyone who has successfully fabricated a bracket for one of these be willing to share their source so that I could get a bracket as well?

2) Which unit should we buy that gives us a battery that is closest to OEM in terms of capacity?

[Groundpilot]

OEM battery needs to be registered to the car, non OEM one needs to be programmed and registered also. If this ignored, new battery will not be charged correctly. Undercharging will cause battery discharge, overcharging will cause electrical component damage and other problems.
I would hate to pay $1K for a battery and lose it in a few month, not to mention other possible problems.
Does anyone know if this battery can be programmed to our cars and how?
I dont think this battery is expensive, considering the amount of weight saving it provides, if it works properly that is.
OEM batteries last for 4 to 6 years.

[italyix]

Originally Posted by Groundpilot

OEM battery needs to be registered to the car, non OEM one needs to be programmed and registered also. If this ignored, new battery will not be charged correctly. Undercharging will cause battery discharge, overcharging will cause electrical component damage and other problems.
I would hate to pay $1K for a battery and lose it in a few month, not to mention other possible problems.
Does anyone know if this battery can be programmed to our cars and how?
I dont think this battery is expensive, considering the amount of weight saving it provides, if it works properly that is.
OEM batteries last for 4 to 6 years.

Program battery to 40agm which is the lowest value accepted by our cars.

With regards to bracketry, mine looks like a bent piece of metal.

[whats77inaname]

Originally Posted by Groundpilot

OEM battery needs to be registered to the car, non OEM one needs to be programmed and registered also. If this ignored, new battery will not be charged correctly. Undercharging will cause battery discharge, overcharging will cause electrical component damage and other problems. Does anyone know if this battery can be programmed to our cars and how?

The car doesn't need to be programmed for a non-OEM battery, just registered, same way as you do an OEM. I've posted how to register it, it takes like a minute, literally. Registration simply tells the car that it's a new a new battery, and to charge it as such. Given that, I don't anticipate a problem w/registering an Li battery.

[Groundpilot]

Originally Posted by whats77inaname

The car doesn't need to be programmed for a non-OEM battery, just registered, same way as you do an OEM. I've posted how to register it, it takes like a minute, literally. Registration simply tells the car that it's a new a new battery, and to charge it as such. Given that, I don't anticipate a problem w/registering an Li battery.

Sounds good

[OneMmmm]

Very interested in this for weight savings, but curious about changes to weight distribution.

The front is already heavier, so reducing ~50 lbs. to rear is worth noting. Especially when paired with an exhaust system like Akra Evo that also reduces the weight significantly.

What are options for improving balance in the front with this?

[Groundpilot]

Originally Posted by OneMmmm

Very interested in this for weight savings, but curious about changes to weight distribution.

The front is already heavier, so reducing ~50 lbs. to rear is worth noting. Especially when paired with an exhaust system like Akra Evo that also reduces the weight significantly.

What are options for improving balance in the front with this?

Maybe remove the engine?

[OneMmmm]

Originally Posted by Groundpilot

Maybe remove the engine?

Thanks for the help. I'll look into this.

[pbonsalb]

Aluminum calipers, lighter wheels, lighter front seats, low washer fluid.

[italyix]

Originally Posted by Groundpilot

Maybe remove the engine?

You forgot to cut the floor board and replace with pedal power. But seriously, yes weight is removed from the rear and when coupled with a Ti exhaust system, weight balance is offset.

That is where a corner balance comes in. Most people will not swap the battery to this unit, unless other mods have already been done to the car to make it more track ready, which assumes adjustable suspension in terms of height.

I did the mod to further reduce weight, in addition to the CF roof and Volks wheels. If I had more money when the project started I would have also swapped out the seats to BMW Performance or Sportsters CS to get even more weight off. Not to say I wont do this next year

[Groundpilot]

Biggest weight reduction can be achieved by removing the engine of course, but on a serious note, there is not much we can remove from the front, its much easier to do it in the rear, which definitely will make this car more nose heavy and unbalanced.
By replacing front seats with Recaros or similar, is not really removing anything from the front.

[Hujan]

Weight distribution is a good point. But how much will removing 55 lbs. from the rear of the car upset handling on a car that weighs ~3,400 lbs.?

And if it does, as "italyix" points out, could that not be restored by adjusting the suspension (but in terms of ride height and adjustable sway bars)?

All that said, I would love to find a way to shed some weight from the front of the car. It would be sweet if the mechanism responsible for the auto start/stop was a discrete object that could be unbolted and discarded with relative ease, but I doubt it.

[Beemdog]

Originally Posted by Hujan

All that said, I would love to find a way to shed some weight from the front of the car. It would be sweet if the mechanism responsible for the auto start/stop was a discrete object that could be unbolted and discarded with relative ease, but I doubt it.

I believe the Auto Start/Stop adds little (if any) weight and utilizes the standard engine starter motor.

[Groundpilot]

This may be a good idea to reduce some unsprung weight. Anyone has used these calipers?
http://www.racingbrake.com/BMW-M3-E9...-p/2161-pu.htm

[Richbot]

Unfortunately with a front engine car the important, difficult to change weight is all on the front, so it's expensive to get rid of. However, while the battery weight is nice and far back over the rear axle, it is not in a "good" place just because it's over the rear axle, so I don't think it's going to hurt the car's performance more than the lost weight will help by any means. That 55lb is about 20" off the ground, about 18" behind the rear axle, and about 72" away from the center of gravity. Inertia about the center of gravity has a big effect on handling, so even if the CG moves slightly forward due to this mod, it will also move down and the rearend's pendulum effect about the CG will be a little less severe. The change in CG can be calculated using scales before and after. The ride height change should be minimal with the spring rates we run back there even in stock form. If it doesn't throw cross weight off significantly (which I don't think it will, because at least my car already has a little bit of wedge in it which this would only help by taking some weight off the LF/RR combo) you're golden, also easily checked with scales before and after. Speeding up, slowing down, and turning 55lb is way harder than just tuning around a slight shift in CG, especially if that shift in CG is a partially positive one (downward)

Anyway, suffice to say my next battery will be replaced with one of these, if I don't get bored/drunk and order one before then.

Also, IMO, the Voltphreaks electronics package is worth it for the added failsafes over some of the other stuff that's out there for much, much less money. Rather have the extra protection there on a street car.

[FogCityM3]

For those keeping the car a while, a regular BMW battery will go out every 3 yrs and cost you $300 each time, while with this, for an extra $400-$500 you'll have something that saves weight and will last 2x-3x as long. The higher end German tuning houses that actually race their cars or have time tests (i.e. SportAuto Tuner GP) on well known tracks replace the regular batteries with lightweight ones as part of weight savings programs and you can't argue with some of the results when several weight saving strategies are used in combination.

[italyix]

Originally Posted by FogCityM3

For those keeping the car a while, a regular BMW battery will go out every 3 yrs and cost you $300 each time, while with this, for an extra $400-$500 you'll have something that saves weight and will last 2x-3x as long.

Voltphreaks states the battery will last ~10 years before it needs to be replaced, plus its serviceable and upgradeable as new battery tech comes out.

Originally Posted by Richbot

Also, IMO, the Voltphreaks electronics package is worth it for the added failsafes over some of the other stuff that's out there for much, much less money. Rather have the extra protection there on a street car.

#1 reason I chose this company. I previously spoke with Braille about their Li batteries and they do not offer low voltage cutoff. Plus the battery was more expensive for less amp reserves. As Voltphreaks is a smaller company, their operating expenses might be lower which allows them to pass the savings to the consumer.

[Hujan]

Originally Posted by Richbot

Unfortunately with a front engine car the important, difficult to change weight is all on the front, so it's expensive to get rid of. However, while the battery weight is nice and far back over the rear axle, it is not in a "good" place just because it's over the rear axle, so I don't think it's going to hurt the car's performance more than the lost weight will help by any means. That 55lb is about 20" off the ground, about 18" behind the rear axle, and about 72" away from the center of gravity. Inertia about the center of gravity has a big effect on handling, so even if the CG moves slightly forward due to this mod, it will also move down and the rearend's pendulum effect about the CG will be a little less severe. The change in CG can be calculated using scales before and after. The ride height change should be minimal with the spring rates we run back there even in stock form. If it doesn't throw cross weight off significantly (which I don't think it will, because at least my car already has a little bit of wedge in it which this would only help by taking some weight off the LF/RR combo) you're golden, also easily checked with scales before and after. Speeding up, slowing down, and turning 55lb is way harder than just tuning around a slight shift in CG, especially if that shift in CG is a partially positive one (downward)

Anyway, suffice to say my next battery will be replaced with one of these, if I don't get bored/drunk and order one before then.

Also, IMO, the Voltphreaks electronics package is worth it for the added failsafes over some of the other stuff that's out there for much, much less money. Rather have the extra protection there on a street car.

Originally Posted by FogCityM3

For those keeping the car a while, a regular BMW battery will go out every 3 yrs and cost you $300 each time, while with this, for an extra $400-$500 you'll have something that saves weight and will last 2x-3x as long. The higher end German tuning houses that actually race their cars or have time tests (i.e. SportAuto Tuner GP) on well known tracks replace the regular batteries with lightweight ones as part of weight savings programs and you can't argue with some of the results when several weight saving strategies are used in combination.

Great information, gents. You both made some great points.

[s85e90]

10 years! Wow. That's awesome!