ngng

do you let your electronics run for a little bit before cranking? at least with the shorais i've had on my bikes it's something that shorai advises you to do to "warm up" the battery (i'm not an EE, so don't quite me on the wording). it seems counter intuitive when you're at a camp ground in the middle of nowhere to drain your battery, but it did make ad ifference

Spyerx

here's the issue, a lot of makers of Li batteries advertise "lead acid equivalent" not REAL capacity.

So there is a reason the Braille are more expensive, they have higher real capacity.

Example:
This is a 25AH battery, 'equivalent' to a 75AH lead acid battery
https://www.braillebattery.com/index...atteries/i48cx

The VF VPR-P6 is a 31AH equivalent which is about 10AH actual
http://www.voltphreaks.com/linked/Vo...sPriceList.pdf

The Anti Gravity Battery is a 20AH EQUIVALENT which is about an 7AH actual
https://shop.antigravitybatteries.co...omotive/rs-20/

khooni

now this makes complete sense.

I was always wonder about how a higher capacity battery do be so cheap. So the 18Ah from porsche motorsport must be nominal and not PB eq. , it can last 2 weeks while parked up without CTEK charging.

and indeed the RS-20 is a startup battery only.

Spyerx

Remember to LOCK your car when parking it for a while. After a week car goes into sleep mode. Mine can sit for well over a month - 6 weeks w/o an issue with a LION battery in it (Braille).

khooni

tx. do you have the i48cx? i take it that's the right size for 997?

ngng

you've got that SoCal weather though!

orthofrancis

I live in SoCal, and have had a Braille GU1R for 2 months - use it as a daily drive - no issues what so ever - lots of radio use/nighttime driving.

7 pounds weight - around $500 39 PbAcid Eq amp hours/13 AH.

That was a cheap way to save about 40+ pounds.

https://www.braillebattery.com/index...batteries/gu1r

sfo

if you double click the lock button to lock the car, you disable the interior motion and lift sensors, which saves current.

khooni

I didn't know that. Tx

Yargk

This is not true in all cases. The RS-20 is sold as a true 20 Ah battery, 50-60 Ah lead-acid equivalent, for $600 (see below, fine print, also it wouldn't weigh 10 pounds if it was 7 Ah). I'm not saying Braille isn't better, however, the price is still hard to justify. Li-ion batteries are now under $140/kWh, so price likely comes from low volume, hopefully testing costs, but it's not materials cost.

Spyerx

I was just reading what was on the tin

Yargk

Thanks for the citation, I'd guess the writing on the battery paints a more accurate picture since I still think you'd have to work hard to make a Li-Ion battery that heavy for that little energy. (shouldn't be 10 pounds if it's only 20 Ah Pb Eq)

BTW: Any norcal track plans?

ngng

btw, deka makes braille batteries. in case you want to save some money

khooni

That’s interesting. We now have 2 numbers for the manufacturer

Johnb55

I've become a huge fan of Voltphreaks LiFePo batteries. They aren't cheap initially, but after numerous failures with other brands of Lithium batteries I think they may actually be cheaper in the long run. They have circuitry and logic built in to protect the battery that seems to be effective. I've been running a Voltphreaks VPH 900 LiFePo in my street driven GT2 for about four years now with zero problems. I've also put them in our Formula Atlantic race cars after experiencing failures with Ballistic, Braille, Shorai, and one other brand I don't recall. We've experienced zero failures with the VoltPhreaks in the race cars as well. Thirdly, I replaced a failed Odyssey PC925 in my Caterham with a VPH900, also zero problems. It's become my go-to lightweight battery.

I've also experienced many failures with Ballistic and Shorai in motorcycles and basically don't use them anymore.

I know this sounds like a sales pitch, but it's not. I have no affiliation with VoltPhreaks other than buying a lot of their batteries. I'm just posting this in hope that someone else finds it useful.