I ordered a custom lithium titanate battery off Aliexpress a while ago, 40Ah 5S (so 10.8-14.0V operating range, newer cars with their computer controlled charging systems might be unhappy) in an H5/group 47 case and put it in my car. Weighs a bit under 16lbs and has an active balancing and overcurrent shutoff BMS. Since it's smaller than the stock group 49 battery and 1/3 the weight, I just used a single sliding clip to hold it in. These probably are grade B or used cells with only 80% of advertised capacity, but I drained the battery pretty low and it cranked the engine much more confidently than the stock battery did when fully charged, and they are supposed to last practically forever and be perfectly usable at -30 degrees, so I'm happy.

Tip for getting the sliding clips off (V8 Vantage): Pull the side trim panel outward so its edge comes forward of the rail for the sliding clips, then you have barely enough clearance to slide the clip off behind the panel and fish it out.

Now I have a nearly brand new AM branded battery sitting around unused lol.

 

How safe are these no-name lithium batteries?

 

Very good question! The physical resilience is a feature of the chemistry, they just don't have thermal runaway issues. Because they're lithium titanate, I feel comfortable despite their questionable origins (I also took it apart and after putting some more foam padding feel okay about the physical support for the cells and the wiring and BMS). For example, these aren't tests that would go well with other lithium ion chemistries:

For lithium iron phosphate, I still wouldn't worry about them catching on fire, but the lower lifespan and low voltage/temperature sensitivity make a warranty more appealing (like you'd get when you buy e.g. Antigravity). I would say if you don't need cold weather tolerance, you're better off with lithium iron phosphate (e.g. Antigravity), of which there are many vendors. LFP is a little bit lighter and the voltage matches car usage a little better (11.2-14.4V). You can get the same size battery for 1/3 the price that Antigravity charges if you order on Aliexpress, but after seeing a lot of disassembly videos on Youtube, definitely tread carefully and preferably buy one that other people have disassembled before and found to be made well.

I got this in case I bring the car to the East Coast someday and don't want to mess with heaters or trickle chargers. I would've happily paid more for a better quality product, but this is literally the only choice short of assembling my own pack (I didn't really feel like finding an appropriate balancing circuit and spending an hour wiring it up). Right now as the car is sitting in California, this battery is massive overkill.

 

Thank you for posting your Lithium install.

I contacted Antigravity twice (email & voicemail) and never heard back from them. I may try them again as I would like to move to their larger Lithium battery and replace the Bosch behemoth in the Vantage.

 

Any links to said battery ?

 

TBH because they didn't do the best job putting it together, I didn't really want to advertise for them, but I just checked and the GTKPower Aliexpress store doesn't sell batteries anymore lol. There actually never was a direct link, they did have a listing for a 40Ah battery but I had to ask for an H5/group 47 battery case (to fit base clamp mount European cars) and a 200A car starting BMS (their most powerful one), which brought the price from 230 to 300.

Here's something nearly identical I can find right now ("Facewell Technologies", probably the same company as "Foxell Technologies" w/ poor reputation), says it's made by GTK (Foxell and GTK probably are the same company): https://www.aliexpress.com/item/1005001321054527.html

You would need to ask for an uprated BMS if you want to use it on an AM or you can use the BMS just for its active balancing function and short out the low voltage/overcurrent cutoff MOSFET bank. The auto translate feature on the website works pretty well if you don't know Chinese. If you want the battery for another car, or if you find a battery you like in the wrong size case, just ask them for a car battery case catalog and if they can fit it into the case you want.

However, your location says SF Bay Area, so I would strongly suggest getting a LFP starter battery. There are some you can find with Amazon reviews and US customer support like MightyMax if you don't mind making a bracket for it and fitting some SAE post terminal adapters. On Aliexpress, these "Moseworth" ones seem to have good reviews: https://www.aliexpress.com/item/4000111903929.html (that's an H5/group 47 size case, probably has no cutoff switch so don't run it flat and keep it trickle charged in the cold, 38Ah -> it probably weighs under 12lbs). I'm actually considering buying one just to try it out, maybe put it in the Vantage as it won't be run in freezing temps for the forseeable future, and <300 bucks shipped is pretty cheap.

 

Two PS30 (2x30Ah) for my V12 since two years without any problems ! Save 17kg

https://www.powerlite-units.com/lith...tteries.html#2

 

How do these work with the battery tender/conditioners? Can you use the OEM unit that goes into the cig lighter?

 

No problem with my OEM cigar/lighter in the trunk.
one specific Lithium tender/conditioner is provided with every Battery
see website

 

The price is a bit too much for those PS30s...300 GBP for each battery, and you need two? I'll pass...

 

My '11 DB9 hated the AntiGravity LiOn I installed, not letting me get out of the neighborhood half the time without going into "crash mode detected" and other limp modes. I had to return it and just got a nice AGM battery, down two steps to a H6 to save a little weight (-7.6 lb). I would love to have saved another 30, but Princess Kate has other ideas on how I should save weight.

 

Thanks for the help. I might try that Moseworth LFP unit, 12lbs is substantial lighter than OEM or even AGM units.
Since the Moseworth LFP does not have protections built in, can I leave it on a trickle charger without risking it blowing up or something? Little worried and I do not know much about batteries.

 

https://www.powerlite-units.com/file...heet_PS-30.pdf

Just looking at the weight of 2.7kg immediately tells me it's not 30Ah. A 30Ah 4S LFP pack weighs about 5kg. They're sneakily using "Pb equivalent rating", you actually have 2 16Ah packs for 32Ah total. That's solid, but I think you overpaid a little. On a v12 I would personally want at least 40Ah for a car that isn't daily driven.

A good way to get 40Ah in the USA if you're willing to put up with the trouble of making a battery tray is two of these: https://www.batteryspace.com/lifepo4...assed-dgr.aspx

A car battery isn't being cycled like crazy so LED balancing is okay. The cells are high quality and high C-rate.

My wild guess is that it probably has a balancing board but not a cutoff circuit, so yes you don't want it to go flat. I didn't bother measuring the parasitic load on my Vantage, but I would guess that if you leave the car sitting around 6-8 weeks it'll kill the battery. You can leave LFP or LTO on a trickle charger, they're not fussy at all about charging, but with a relatively big 40Ah battery you really don't need to trickle charge it most of the time, maybe plug it in occasionally in the winter if the car sits unused (to avoid the alternator attempting to push a large current through a cold battery, only LTO and lead acid can tolerate that). Bay Area winters are mild but on colder days it's near freezing, and that could be bad for a battery that's low on charge.

I think our cars have 130A alternators so it's not as dangerous as running on say a modern Porsche or BMW with a 180A alternator, but at idle it's still enough to push 40A charging current to the battery which is pretty substantial.

 

Thanks, just pulled the trigger on the Moseworth LFP unit.

 

Sorry to hear your car didn't like the lithium battery, maybe the newer cars have a different ECU? Next time your battery goes, I think you can actually go down another size and save a few more lbs (H5, -14lbs). I think typically for AGM, H5s are 60Ah, H6s are 72Ah, H7s are 80Ah. The reserve capacity is still plenty.

For people who are brave enough (or daily drive their cars) to run something as small as the Odyssey PC680 and don't want to go lithium ion, an easier solution without the custom bracket and a bit more capacity is group 90/T5 (33lbs, about 40Ah) or group 42, (35Ah and 28lbs). The tabs at the bottom of a group 42 may need a little trimming but that beats a custom battery tray. If the starter needs some more help, you can add ultracapacitors in parallel (it takes very little to provide vastly improved starting, as you're adding on top of the battery's power, just 60 farads will crank a warm 4L engine on its own).