Lightweight battery options

P

philipw

Member
 Bristol
Hi All,

Current battery is nearing the end of its life so decided to replace with a more lightweight option.

Do any of you have experience with Li batteries and their expected life. Looking at options from Liteblox and Deadweight.
 
Is the car used frequently, or left for weeks on a trickle charge/battery conditioner?

I’ve seen a few posts on smaller/lightweight conversions…some times to gain a bit of boot space, and some times for weight loss for track work. Don’t remember either of those names though, the only ones I remember are Braille and Odyssey.

However, I’ve no direct experience of either.
 
I’m bumping this up to ask the same question about lithium batteries.

My normal battery has just died-won’t charge past 12.3/12.4V and drops to 11ish overnight.

I recently lost my garage so am parked underground and can’t trickle charge for the time being. I’m reluctant to buy a normal battery as I only use the car 1-2 times a month max. I could, of course, disconnect it but it’s a hassle and I will inevitably forget and kill another battery.

I don’t expect many have gone the lithium route given the cost but it seems like it might ‘almost’ pay for itself and save a few kg in the process!

Any thoughts on brands and suitability are greatly appreciated :thumbsup:
 
Surely it's just easier to disconnect if you use it so little. Or put an isolator switch in.

Does the M have an adjustable battery tray? You could fit the smallest physical size that meets the CCA required to start.

Lithium look *very* expensive and have smaller capacity for the same physical size. I'd not be tempted to take the risk.
 
Whilst disconnecting isn’t difficult, it’s an added hassle I was hoping to avoid. I had a period of time where I was doing that and it got old pretty quickly.

The battery is buried under the carpet bulge and inflator, there are, iirc, 2 holes for different size battery clamps. Removing the carpet cover is a minor fiddle but it’s the wear and tear on the prongs I’d like to avoid.

A simple kill switch could be a solution but I don’t want to get in to chopping up the wiring.
 
Does ANY car manufacturer use Lithium 12v batteries in cars?, they require different charging programs, all the cars I know either use Lead Acid AGM or Flooded cell batteries that are cheap and easily available.
 
BMW, Porsche and probably others. Most aftermarket ones designed for starting a car have a built in BMS to regulate charging. More modern cars will no doubt do that via the ECU where different charging profile can be set.
 
I've had a Deadweight Touge 500 for 3 years and can't fault it. My car has been SORN'd a lot during this period, but when it's on the road I just don't think about the fact that it has a LiFePO4 battery at all. It also cranks noticeably harder/faster than the OEM batteries I'd had beforehand.

There's some parasitic drain in my car and the BMS has kicked in once after 3+ months of no use (couldn't tell you exactly how long; might be longer). It's a much better experience than with a lead acid battery - it just turns "off" and there's no risk of damaging it with low charge levels. It also doesn't lose any charge if you decide to disconnect it.

Very expensive of course, unless you are talking £/kg, in which case it's one of the best mods you can do. I e-mailed deadweight asking for a forum discount and they were happy to take 5% off.
 
beanie said:
BMW, Porsche and probably others. Most aftermarket ones designed for starting a car have a built in BMS to regulate charging. More modern cars will no doubt do that via the ECU where different charging profile can be set.
Click to expand...
The BMW M series amongst them apparently but not M40, technology had overtaken me, thanks.
 
MrPT said:
I've had a Deadweight Touge 500 for 3 years and can't fault it. My car has been SORN'd a lot during this period, but when it's on the road I just don't think about the fact that it has a LiFePO4 battery at all. It also cranks noticeably harder/faster than the OEM batteries I'd had beforehand.

There's some parasitic drain in my car and the BMS has kicked in once after 3+ months of no use (couldn't tell you exactly how long; might be longer). It's a much better experience than with a lead acid battery - it just turns "off" and there's no risk of damaging it with low charge levels. It also doesn't lose any charge if you decide to disconnect it.

Very expensive of course, unless you are talking £/kg, in which case it's one of the best mods you can do. I e-mailed deadweight asking for a forum discount and they were happy to take 5% off.
Click to expand...

Thanks for the reply :thumbsup:

I didn’t realize the deadweight had a low level shut off, I’d seen the ‘restart’ features on other brands like antigravity and liteblox but they’re a bit more costly-particularly the liteblox!

I take it you don’t disconnect it?
 
Ah, I think the antigravity restart feature is a bit different in that it effectively guarantees enough juice is left for a start. This is just standard over-drain protection, which may or may not leave enough to start a cold S54 that hasn't been turned over in a while. I doubt you'll see many LiFePO4 batteries without BMS as they get a bit explodey if overcharged.

Oddly enough, I just decided to disconnect the battery yesterday (along with setting mouse traps around the car etc for winter!). It's been off the road for four months but I bet it would still start based on nothing more than how "peppy" it seems when you open the door, turn the ignition on etc. :lol:
 
Good to know the over-drain feature is there, will save you knackering it if/when you forget.
 
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