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Discussion Starter · #1 ·
Guys,

Just a heads up. If you ever contemplate purchasing a 6.5 lb Volt Freaks battery and live in the colder states, be prepared to use the OEM battery in the winter months. When the temps are in the teens or even the 20's you have between 48 - 72 hours until your car will be completely dead if sitting. Never a problem in the summer months but the winter is certainly a problem for this battery.


Cheers ///
 

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What is the condition and how many amp hours is the battery?

Did you test the voltage? Could be the battery has sulfur buildup and is not holding a full charge. Also if its not a sealed battery it could need water.
 

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Any idea of the cold performance?
You might check the link I provided.

Their PC 1500 offers CCA: 825A at 0°F & reserve capacity: 135 minutes. Also absorbed glass mat (AGM) technology, won't pit your exterior finish.

VoltFreaks are great for removing vehicle weight and starting in temperate weather, but their limited (~42 minutes) reserve capacity limits their all-around value.

I prefer to know the battery will start my M in extreme weather and won't run out of power if I leave the emergency lights flashing if stranded by the side of a road. Hopefully better lithiums are on the horizon.
 

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The Voltphreaks battery is a good product, but you really need a trickle charger to keep it happy for extended periods of sitting.

Dave
 

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You might check the link I provided.

Their PC 1500 offers CCA: 825A at 0°F & reserve capacity: 135 minutes. Also absorbed glass mat (AGM) technology, won't pit your exterior finish.

VoltFreaks are very light starting batteries but have little reserve capacity.

Thanks I did....

Any idea how this compares to the stock battery?
 

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Thanks I did....

Any idea how this compares to the stock battery?
The OEM is CCA ~720 vs 825A and the reserve is ~120 OEM vs 135 minutes.

As our Ms are power hogs when not running, the greater reserve time will not let the battery discharge as much when sitting. Lead acid batteries do not like deep discharge, shortens their lifespan. If you get stuck in snow, or simply enjoy listening to music with the engine off, get as high reserve as possible.

Comparing cold cranking amps, make sure to compare at zero degrees, not the commonly used 32 degrees.

Gel batteries should last longer than traditional lead acid construction, and being sealed, won't cause rear body pitting caused by the vented OEM battery.
 

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so is there a practical way to get a much lighter battery? seems like an amazing way to save a lot of weight in the rear end, which would be great. I remember searching for this info a while back but there were no good threads on it.
 

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Plenty of info on the e39 side under 'weight savings'. This and other batteries are looked at. The stock battery is an acid and lead monstrosity...an easy target for weight savings.

Dave
 

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Plenty of info on the e39 side under 'weight savings'. This and other batteries are looked at. The stock battery is an acid and lead monstrosity...an easy target for weight savings.

Dave
+1

Our batteries are the uncommon size group 49, and limited alternatives are either replacement lead-acid (~$125), MAT gel (~$250) or Lithium (~$550+). Prices are general reference only, shop around for better deals.

IMO the MAT gel are the best compromise of reduced weight and reserve power. They are safer in a rear end collision and completely sealed. The OEM batteries are vented outside and the corrosive vapor over time will pit the rear bumper area.

Lithiums are really light (~5 lbs) and expensive, but not much reserve.

The lightest setup that won't leave you stranded is possibly hooking up 2 Voltphreaks, 1 powering the car, the other charging as a backup. If the primary fails, switch to the secondary.

The ultimate setup would relocate Voltphreaks under the hood and remove the long and heavy battery cables to the trunk.
 

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+1

Our batteries are the uncommon size group 49, and limited alternatives are either replacement lead-acid (~$125), MAT gel (~$250) or Lithium (~$550+). Prices are general reference only, shop around for better deals.

IMO the MAT gel are the best compromise of reduced weight and reserve power. They are safer in a rear end collision and completely sealed. The OEM batteries are vented outside and the corrosive vapor over time will pit the rear bumper area.

Lithiums are really light (~5 lbs) and expensive, but not much reserve.

The lightest setup that won't leave you stranded is possibly hooking up 2 Voltphreaks, 1 powering the car, the other charging as a backup. If the primary fails, switch to the secondary.

The ultimate setup would relocate Voltphreaks under the hood and remove the long and heavy battery cables to the trunk.
The Oddessy battery weighs 49 pounds? Do you have a favorite for gel batteries that are lighter?
 

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We actually advice against the Voltphreaks battery for M5's unless it's for race use only, as a daily driver, the latest M5's are very advanced cars (read: lots of electronics) that even draw power when parked. The Voltphreaks 6.5# battery just doesn't have a huge buffer (in fact any small lightweight battery is a compromise).

As for the cold start issues, we are working on that. Hopefully we can improve the cold start performance so the battery is "less of a compromise". Also we are working on making it harder to abuse the battery.

- Tony (voltphreaks.com)

so is there a practical way to get a much lighter battery? seems like an amazing way to save a lot of weight in the rear end, which would be great. I remember searching for this info a while back but there were no good threads on it.
 

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Alternative batteries

If performance specs meet or exceed OEM, other size batteries can be substituted if they fit the battery well.

OEM size 49 battery size specs: 15" L X 6/78 W X 7 3/16 H

Optima sells a size 34 battery (D34) which should fit in the battery well.
Reserve Capacity - 120 minutes
CCA @ 0 degrees F. - 750
Weight 43.8 lbs
$189.95 list (inc. shipping)

http://www.1st-optima-batteries.com/index.asp

Direct size 49 replacements:

Sear DieHard Item #02833349000
Reserve Capacity - 140 minutes
CCA @ 0 degrees F. - 805
Weight 52.0 lbs
$129.99 list

http://www.sears.com/shc/s/p_10153_...+Chargers&sName=Automotive+Batteries&sLevel=3

Odyssey Drycell PC 1700T
Reserve Capacity - 156 minutes
CCA @ 0 degrees F. - 875
Weight 52.0 lbs

http://www.batteriesplus.com/pc-289...military-grade-battery-with-sae-terminal.aspx

Closest direct replacement for OEM battery, without the dealership price:

Werker SLI49-LI
Reserve Capacity - 120 minutes
CCA @ 0 degrees F. - 850
Weight 56.5 lbs

http://www.batteriesplus.com/pc-36496-36496-SLI49-LI.aspx
 

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Discussion Starter · #19 ·
We actually advice against the Voltphreaks battery for M5's unless it's for race use only, as a daily driver, the latest M5's are very advanced cars (read: lots of electronics) that even draw power when parked. The Voltphreaks 6.5# battery just doesn't have a huge buffer (in fact any small lightweight battery is a compromise).

As for the cold start issues, we are working on that. Hopefully we can improve the cold start performance so the battery is "less of a compromise". Also we are working on making it harder to abuse the battery.

- Tony (voltphreaks.com)
Well since this is different information that I received a few months ago, I will assume I am/was the test mule for the E60 M5.

That being said, I would still recommend this battery for warmer climates or as suggested above, for racing.

Also, it is just not the "extended sitting time" that is problematic for this battery. With temps below freezing and battery being fully charged, it only takes a couple/ three hours of sitting to start losing your settings (time and date being the first to go).


Cheers ///
 

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I've had my 2nd Volthphreaks 6.5lbs battery on my E39 M5 since October 2007 and have had no issues as I have it hooked-up on a battery tender jr. trickle charger... Car is hibernating in the garage for the winter but when the weather is nice, I take her our for a nice drive and everytime starts right up.

As I mentioned this is my 2nd battery from Voltphreaks and the story with the first one is the same as what you've reported... I left the car in the garage for a week and the battery was totally dead. I really don't think this is the fault of the battery as it does what it's rated for as a battery and one thing very important to consider is when we hook it up to our E39 or E60 M5's with all it's electronic gizmos still awake even when the car is not running, it'll just drain the life out of the VP battery.

So if you want this extremely lightweight battery and you won't be using the car for at least 2 days then go hook it up to a trickle charger.

Very nice mod for its weight savings as long as you're well aware of it's maintenance requirements.
 
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