vph_tony

They both can if you keep in mind that the car might last half as long in storage (say 2 weeks versus a month, etc). Also in cold weather it might be more sluggish compared to the stock battery if you get the smaller Voltphreaks batteries. One tip is to leave the high beams on for a minute or two to warm up the battery before trying to crank the car.

BTW a few failed cranks with the Voltphreaks battery will also warm it up, as long as the starter actually turns. If it's just clicking, it might not draw enough current to actually warm up the battery though. This is different than the PC680, which will fail when it's close to empty. The Voltphreaks battery will keep delivering power for most of it's discharge. For example you can start the car when the battery is close to empty (say, 20% full). Once it's empty, you won't be able to start the car. A lead-acid will "indicate" it's charge status by being more sluggish as it gets closer to empty.

- Tony

kos11-12

Hi ,DMS technologie or rally design in UK are provading racing batteries that are 1/2 of the wheight for the same power but you would always have to change the ends of your wires to conecte, not a big deal I have try them on motorcycles for 3 years they hold they charge even better and are obviously sealed.
Konstantin

LA964RS

Tony...thanks for coming over here and answering q's, it is really very helpful. Also, thanks for answering all me emails so quickly.

NOTE: There is a duplicate thread under this heading in Water Cooled under 997GT2/GT3. I posted there that people following the thread should come here for info...but Tony you still may want to check it out.

Robert Linton

Where is the statement on the Voltphreaks web site that said 'you can leave the car for 2-3months with the 6 lbs version, 1-2 months for the 4.5 lbs version and 2-3 weeks for the 3 lbs version'? My apologies it is as pointed out below, in the battery tender section:
VPHR7: 2 to 3 weeks
VPHR12: 1 to 1.5 months
VPHR18: 1.5 to 2 months

Robert Linton

One other question. As Voltphreaks is an LLC which I assume has little or no assets, is there any real value to the warranty or can you simply walk away from any potential liability or problem? I do not mean to be rude or impolite, I would, however, like to know if there is anything real standing behind the battery or do you simply buy parts from A123 or another vendor, have someone such as Greer make the casing and sell it?

Robert Linton

Tony, I am all in favor of and supportive of experimenting. I just need to know the facts so that I can adequately evaluate risks. I have now bought two of the 6 lbs batteries and would like to know the true statistics, e.g., can it hold charge for 2+ months without charging?

LA964RS

Robert look under "battery tender"

https://s.p10.hostingprod.com/@www.v...products_id=39

vph_tony

It depends on the car. In our Civic, it holds a charge for over 3 weeks (we haven't gone tested beyond this). We've let our M3 sit for 2 weeks (we haven't gone beyond this). All cars, even the same model, are different though.

The 2 months estimate is based on extrapolating from the above, and current draw measurements. Cars with a lot of electronics and a higher idle current draw won't last as long, like the BMW M5. The M5 seems to possibly draw several amps for a period after shutting down before entering a "sleep" mode, for example. We don't have an M5 to test, we are getting this information from googling. There also may be periodic "ventilation" where the fans of the climate control unit turns on once in a while, etc, that draws more current. Options like that reduce the time. The stock M5 has a 80Ah OEM battery for a reason!

There might be other cars like this. By "lasting as long", just to clarify, it means how long you can park the car and still start it up (for example when going on vacation for 2 weeks, etc).

We have just updated the numbers listed on the battery tender page again, to be more conservative.

BTW how have the 6lb batteries worked out, have you noticed any issues?

- Tony

vph_tony

We will stand behind the product as long as the company remains solvent. We don't plan on going out of business, but we are a small company, and yes that is a risk for customers to consider. We don't plan on walking away from warranty issues, and will replace/refund defective products (we have a 5 year pro-rated warranty).

- Tony (voltphreaks)

Erik

I will continue following this thread and the one on the GT3 board to see how it pans out. My biggest concern is the lenght that it will hold a charge, and the seemingly large draw that the GT3 seems to have. If I leave my V1 radar detector on for more then 4-5 days, my stock battery is empty.

Robert Linton

Have just ordered another Voltphreaks 6 lbs battery. Will have engineers in England and America testing it and the Tek Battery in the hope that either or both can be used for a variety of purposes.

Robert Linton

Does the Voltphreaks have an over volt protection circuit?

vph_tony

No, it can handle maybe 17V or so, but it will shorten the battery's life. Adding overvoltage protection would greatly increase costs also, since the circuit would have to handle 800 amps. Something to keep in mind, a lead-acid battery has no overvoltage protection either, and will bubble or possibly burst if overcharged.

If you overvoltage the Voltphreak's battery, it will overheat after a while since all that energy being supplied to the battery will be converted to heat, and the battery or the surroundings will possibly catch on fire (but not explode). Keep in mind you'd also need a charger that is capable of supplying a lot of current at high voltages (a higher powered charger).

- Tony

mkozink

Any updates?

LA964RS

Robert, sent you a post-SEMA PM.