Voltphreaks 5.5 lbs lithium-ion nano battery
#46
1. cover the positive terminal and any "hot" exposed conductive surfaces.
2. Get a proper seal between the battery and the gas tank and lay the battery on it's side (to make it more secure and to lower its tiny little CG.)
What I see is the only thing "holding" the battery is the bent over end of that aluminum strap ... in a roll-over (perish the thought) if there's not enough friction in the clamping effort of the tab, the bent over end will not hold the battery, which is then free to bounce around on top of the gas tank, at least potentially opening a leak or severing a line? As they say "expect the best, plan for the worst." : )
Also, the "reset" line is a positive voltage circuit -- it needs a very small fuse at the battery end to prevent it turning into a igniter -- if the outer insulation of the wire is severed and shorts to ground, the short circuit can heat the length of that thin wire enough to start a fire in surrounding materials. I know: paranoid, extremely unlikely, but there it is. : )
#48
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Great post. I'd suggest two things:
1. cover the positive terminal and any "hot" exposed conductive surfaces.
2. Get a proper seal between the battery and the gas tank and lay the battery on it's side (to make it more secure and to lower its tiny little CG.)
What I see is the only thing "holding" the battery is the bent over end of that aluminum strap ... in a roll-over (perish the thought) if there's not enough friction in the clamping effort of the tab, the bent over end will not hold the battery, which is then free to bounce around on top of the gas tank, at least potentially opening a leak or severing a line? As they say "expect the best, plan for the worst." : )
Also, the "reset" line is a positive voltage circuit -- it needs a very small fuse at the battery end to prevent it turning into a igniter -- if the outer insulation of the wire is severed and shorts to ground, the short circuit can heat the length of that thin wire enough to start a fire in surrounding materials. I know: paranoid, extremely unlikely, but there it is. : )
1. cover the positive terminal and any "hot" exposed conductive surfaces.
2. Get a proper seal between the battery and the gas tank and lay the battery on it's side (to make it more secure and to lower its tiny little CG.)
What I see is the only thing "holding" the battery is the bent over end of that aluminum strap ... in a roll-over (perish the thought) if there's not enough friction in the clamping effort of the tab, the bent over end will not hold the battery, which is then free to bounce around on top of the gas tank, at least potentially opening a leak or severing a line? As they say "expect the best, plan for the worst." : )
Also, the "reset" line is a positive voltage circuit -- it needs a very small fuse at the battery end to prevent it turning into a igniter -- if the outer insulation of the wire is severed and shorts to ground, the short circuit can heat the length of that thin wire enough to start a fire in surrounding materials. I know: paranoid, extremely unlikely, but there it is. : )
#49
Thanks, Tony.
I think your default setup is great for the RS, where the car is relatively new and electrical is fairly trustworthy.
We've owned a few vintage cars and have had some screwy electrical problems over the years, so I wanted to understand how this protection scheme would effect them. I usually use Odyssee batteries in them due to their weight, deep cycle and long-term storage (when kill switch enabled).
For that application, I'd probably want the battery to act as it does now, not allowing the car to start if it was below a threshold, but allowing it to fully discharge (if necessary) when the engine is running (though I'd like some sort of indicator that it has hit the threshold).
Thanks
I think your default setup is great for the RS, where the car is relatively new and electrical is fairly trustworthy.
We've owned a few vintage cars and have had some screwy electrical problems over the years, so I wanted to understand how this protection scheme would effect them. I usually use Odyssee batteries in them due to their weight, deep cycle and long-term storage (when kill switch enabled).
For that application, I'd probably want the battery to act as it does now, not allowing the car to start if it was below a threshold, but allowing it to fully discharge (if necessary) when the engine is running (though I'd like some sort of indicator that it has hit the threshold).
Thanks
If you want to let the battery fully discharge, the battery can be ordered with a LVC (low voltage cutoff) set to 11.5 volts. This lets the battery fully discharge, while still protecting the battery from being damaged due to over-discharge. Note that the cutoff is active, if you left the headlights on, the battery won't be damaged! From this posting, it appear's Porsche's OEM option has an alarm instead of an active cutoff, which would still let the battery discharge if the headlights are left on and no one is around to heed the alarm:
https://rennlist.com/forums/997-gt2-...boxing.html#12
In general, cars that are more street are ordered with a 12.5V setting, while cars that are more track cars are ordered with the 11.5V setting, just in case the alternator dies during a race, the battery will last longer!
- Tony
#50
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Thanks Tony for the clarification. I think my battery was set at 12.5V so it has some reserve left to start the car back up if battery is drained
#51
For whatever reason, the 997 GT3 always drains the battery. I used to treat it as part of an aerobic workout to have to push it out onto the driveway and roll start it at 6:00am trying to get to the track ... : ) ... and handy to avoid waking the kids!
#52
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Thank god I have a steep driveway. I just let my RS roll down the driveway if I have a dead battery lol
#53
Sale on Voltphreaks lithium batteries
Until the end of June 2010, we'll giving a $300 discount off the VPH750 or VPH900 to anyone on the rennlist forum, just mention rennlist discount when ordering and we'll refund $300 after your purchase.
- Tony (voltphreaks.com)
- Tony (voltphreaks.com)
#54
If someone has an older 911 or a Turbo with more gizmo's, the 900 is probably worth the $100 ... VPH900
Can I ask what's the motivation for the discount? Just generating cash flow (we're in a recession after all) or planning on a new model? At $999 for a Phreak battery, much as I prefer to buy OEM Porsche, $1700 is daft no matter how you cut it. It seems to me, the exotic battery technology is coming into reach. Is this being pushed by something emerging from R&D that's coming into consumer products?
Things are changing -- it won't be long before the after-market vendors are offering electric hub motors and nickel-hydrogen power cell regulators. : )
#55
$999 for the VP750 seems pretty appealing for the amateur racer or hard core weekend driver.
If someone has an older 911 or a Turbo with more gizmo's, the 900 is probably worth the $100 ... VPH900
Can I ask what's the motivation for the discount? Just generating cash flow (we're in a recession after all) or planning on a new model? At $999 for a Phreak battery, much as I prefer to buy OEM Porsche, $1700 is daft no matter how you cut it. It seems to me, the exotic battery technology is coming into reach. Is this being pushed by something emerging from R&D that's coming into consumer products?
Things are changing -- it won't be long before the after-market vendors are offering electric hub motors and nickel-hydrogen power cell regulators. : )
If someone has an older 911 or a Turbo with more gizmo's, the 900 is probably worth the $100 ... VPH900
Can I ask what's the motivation for the discount? Just generating cash flow (we're in a recession after all) or planning on a new model? At $999 for a Phreak battery, much as I prefer to buy OEM Porsche, $1700 is daft no matter how you cut it. It seems to me, the exotic battery technology is coming into reach. Is this being pushed by something emerging from R&D that's coming into consumer products?
Things are changing -- it won't be long before the after-market vendors are offering electric hub motors and nickel-hydrogen power cell regulators. : )
#56
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That is one hell of a deal! I love my 5 lbs Li-ion battery. So far hassle free and the low voltage cut off is a must. I have the tendency to leave things on inside of the car after track day. No more dead battery
#58
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#59
#60
Motivation is just that things are slow, and we want to start things up! Nothing new is coming, though we're always making small incremental improvements, but nothing major. As for Voltphreaks versus Porsche OEM, besides the OEM advantage, the Voltphreaks battery is lighter and actually better (more powerful). It also has the LVC feature to prevent damage from over-discharge, which I believe the Porsche battery does not have. - Tony