I am curious as to how far you have gotten in this project, and I have a couple of questions and a suggestion.
Hove you considered an Optima battery?

The sliding clips seem to be a ***** to remove. One removed, why not cut an inch or so from each side (up to the screws) so they are easier to install and of course remove?

Finally what's the exterior demensions of the original battery?

Thanks

 

The project is finished. I've got one installed in my car and have been driving around with it for a week now. Another forum member has one as well, he's welcome to post his thoughts and impressions if he'd like to give an unbiased review. I'm a fan of open communication so here's a whole bunch of info...

OEM Battery

The OEM battery is roughly 13.25" x 7" x 7.4" and weighs 53.5 lbs. It has a few serious problems:
1) It's extremely heavy so removal/installation in the car is physically horrible on your back and it's easy to accidentally damage your interior bumping it into a trim piece.
2) The weight of the battery adds to the excessive weight of a small car of lightweight construction that weighs way too much.
3) The battery is so large that installing it requires removal of a bunch of trim pieces for access.
4) The sliding clamps are Satan incarnate.

To make replacement easier - especially given how many times I removed the battery over the last couple months during designing, prototyping, and testing my lightweight mount - I cut a small notch out of the carpet trim piece. I only did a small section of the backing portion (the hard backside edge that doesn't have carpet on it) where the sliding clamp hits. This made removing the sliding clamps MUCH easier, but it's irreversible and if you mess it up, you mess up the carpet.

Battery Replacement Options


I did a lot of research in this before making a decision. I ruled out Optima pretty quickly because their batteries don't offer the weight loss I was looking for. I could get about 10 lbs out of the car by using a Redtop. AMR uses Redtop batteries in their race cars, and that's the weight loss they specify, too. Their kit is available but it's expensive for what you're getting. I narrowed batteries down to Braille and Odyssey. I've used Odyssey batteries before, and they're good batteries. The PC1200 is close to a Redtop in specs and weight. Below that is the PC925, and below that is the PC680. Meanwhile, Braille has the B3121 (among others). I gathered all of the specs I could find - weights, dimensions, cranking amps, reserves, etc, and compared the batteries. I ended up going with the Braille B3121. Here's a summary of what I decided:

• Odyssey PC680: Smallest one with most weight loss, but least powerful with lowest reserve. Far less powerful and with half the reserve of the Braille, with only a 5 lb drop in weight (PC680 is 16 lbs, B3121 is 21 lbs). The 5 lbs wasn't worth the risk of accidental full-discharge.
• Odyssey PC925: Very similar to the Braille but 5 lbs heavier.
• Odyssey PC1200/Optima Redtop: Only a 10 lb weight loss, not worth the effort.
• Braille B3121: Plenty of cranking power (used on big V8 race cars), enough power reserve that the battery doesn't need to be babysat on a tender if not driven regularly (still recommended, just like the OEM battery), and would get me a 30 lb weight drop compared to the OEM battery. Best combination of all requirements for cranking power, power reserve, and weight loss.

Lightweight Battery Kit

The lightweight kit installs the same way as the OEM battery - it retains the use of the sliding clamps. The good news is that you're not fighting the heavy OEM battery and the clamps at the same time. You can just set the base in its place and then get the clamps on it. Slide the clamps in place, then tighten them down. Then set your battery on the base, put the bracket over the battery, and bolt the bracket in place. Then hook up the battery. Button everything up, and you're done. The best part, though, is that next time you need to replace the battery, it takes 5 minutes. You pull the parcel shelf out, unhook the battery, undo the bracket bolts, and the battery lifts out without removing any of the carpet, trim, etc. You never have to touch the sliding clamps again unless you're removing the battery mount entirely.

I did look at doing a modular design initially, so other batteries would be able to fit. But cost, complexity, and strength would have all been compromised. Especially not worthwhile considering that this is a very low-volume product. So I chose a single battery that offers the best weight loss with lowest risk of accidental depletion.

Availability

Mentioning this because it came up in the other thread... This is a very grey area for forum rules (you guys do know I'm just a volunteer on here, right?). I wanted to cover this to get it out of the way.

Yes, I do sell these - but no, I don't advertise them or anything else on here. I showed the battery mounts in my "Time to get nimble" thread because it was a project I was doing before I started a company to sell them and other things. The catch cans I designed were picked up by Stuart and are sold through VelocityAP. That's why I wasn't shut down for doing the group buy for those when I first designed them, but was shut down when I tried doing a group buy for the battery mounts.

I decided to start my own thing because I have a bunch of ideas for projects I want to do, and honestly I've always wanted my own company anyway. It's something I'm passionate about so I had to go for it I can't advertise them or anything else on here because I'm not a sponsoring vendor. I keep it separate from this so there isn't a conflict of interest. Based on the messages, emails, texts, and phone calls I've had with forum members over the last few years, I think my contribution would be greater to the forum in my current capacity than it'd be as a vendor.

Also, a quick shout-out to Stuart: When I told him I was starting my own thing, he allowed me to sell the catch cans myself even though our original agreement was for him to be the exclusive seller. VelocityAP still sells them, too. Just wanted to give him props for that because it was a really stand-up thing to do.

 

Thanks for the detailed reply.
I know you can't give active links on the list, but can you email me directly with the website address of your new venture?

 

Hi Telum01


dose that braile battery work for DB9?
also I have installed Dash cam in my car with ability to record in parking mode, even when car is off. I have power magic pro Installed so I can set the parameter that if battery voltage drops to 12 V camera will shut off. do you think I am better off with regular AGM battery vs light weight battery?


does your battery mount fit 2009 DB9?
please feel free to pm me pricing info on battery tray


thx

 

It should fit just fine as I believe the V8V and DB9 (among other Astons) use the same battery. The main concern I'd have is the increased drain on the battery while the car is sitting because of the dash cam. If it has an auto-shut off feature, that's great, so long as the battery can still crank the big V12 at that cutoff point. I had a guy lined up in London to test it in his V12V but he disappeared a couple months ago, long before the project was finished.

 

Installation guide to add to the above info:

https://www.6speedonline.com/forums/...placement.html

 

And following up on DB9 fitment...

Based on this:
https://www.6speedonline.com/forums/...ml#post4208779

It looks like there's a lip that covers the forward-facing side of the battery's mount (where the sliding clamps are on the V8V). And there's a bolt-in hold-down bracket that pushes straight down on the rear side of the battery's base. If that's the case, the lightweight mount should still install just fine - the base of the battery mount is the same shape as the base of the OEM battery. So all the OEM hardware should still work and be retained.

 

compared to original battery how much reserve does braille battery has ?

 

OEM Varta: 53.6 lbs, 680 PC Amps*, 90 Ah, 2 hrs 50 mins reserve
Braille B3121: 21 lbs, 1380 PC Amps*, 31 Ah, 1 hr 15 mins reserve
PC680: 15.4 lbs, 520 PC Amps*, 16 Ah, 24 mins reserve
*comparing cranking amps between battery manufacturers is difficult/impossible because each uses its own rating system.

Back to cranking a V12, this is from Braille's description of the B3121 on their website: Used in everything from large Harley Davidsons to Corvettes & Vipers.

 

The odyssey PC680 is by far my favorite battery. Don't let its looks or paper specs fool you, dry cell batteries behave totally differently. On paper it looks weaker but in the car they crank up way faster than standard lead acid batteries.

Also as long as you drive the car once every two weeks and don't live in sub zero environments it's by far the best option. THe BMW guys already made a perfect battery box for it that utilizes the stock lower lip on the tray so installation is a breeze. (If I remember correctly it's called the Russ Wiles battery box)

I ran the PC680 on my M3 for 4 years with almost no problems. The other added benefit is if you ever happen to draw it down by not driving it for months, it charges up insanely fast and can be drawn down dozens of times to zero and recharged with no negative consequences.

If you draw down an Optima even once, the battery is toast. I will never buy an optima ever again

 

Almost no problems? What issues did you have. It looks like a possible what I need.

 

The only issue I had is if I never drove the car for months, other then that it's absolutely problem free. It cranks up the car much faster than standard lead acid battery. Normal batteries usually take 3-4 cranks to fire up... The PC680 would literally fires usually on the first crank rotation, almost instant fire up.

The battery reserve capacity is a lot less of an issue than people claim. Don't let that dissuade you. And for those who run trickle chargers all of this is totally a non issue anyways.

PC680 is also the lowest price and most readily available option bc almost everyone uses them (and for good reason). Go for the maximum weight savings otherwise you might as well stick with stock, going half way is kind of pointless.

 

The Braille B3121 and Odyssey PC680 are both AGM batteries. If you want to sacrifice half the reserve capacity of a battery to get 35 lbs of weight savings instead of 30, by all means.... it's risk to reward as far as I'm concerned!

 

I was never once ever straded bc of a PC680 ... Ever. Not even in 32F weather.

No need to be concerned about reserve capacity. It's got more than enough.

 

Just a quick shout out to telum01 for the video on battery replacement. I laid out the tools you mention, and ran through the steps. Changed my battery in 35 minutes from parcel shelf in to parcle shelf back in. And I agree; those clamps suck ***. I went ahead and notched my trim for the next guy with a pair of tin snips...
Seriosly though; Thank you so much for your helpful videos. 1st beer's on me if you're ever in Tampa.