LTO Starter Battery

[grinchy]

Can't argue with the weight and that does speak to me. I've tried pretty hard in all my mods to add minimal weight. Though I haven't really attacked the problem by removing stock weight.

The failure to start, is that a real or perceived problem? I do a ton of weekend camping and never have a problem with lots of doors open, lights, charging, cellular booster. The reality is that the standard battery has a solid 80Ah reserve. My single upgraded Group 31 has 120Ah of reserve. I don't hesitate to use deep into the reserves on occasion as I know I'll charge it shortly after, and ultimately FLAs are cheap and easy. LED lights do a ton to mitigate draw. I think many perceive the stock battery to have poor capacity, because they may really been dealing with aged or failed batts. Otherwise, a healthy battery has tons of reserve capacity. Then portable solar handles the rest if I'm really using reserves with things like an electric blanket.

Still, I encourage you to give it a try. I know you're more than capable and up to the challenge. Always different ways to skin a cat and just talking through it before you take the jump.

Battery capacity per Lexus is 64aH.

I personally had an SLA/FLA no start twice in the 200 (same battery on it's way out). No warning as usual, just a dead battery cell. Thing is, it happens to everyone. It is the norm. And we just go on down to the battery supply and buy a new one. My minivan is on it's 4th SLA. My Acura also got 3x new ones when I had that. These are all 'oem' from the dealership (price is fine, warranty is better, and they are proven to fail . . .) Each lasted about 3 years. It's just normal, but part of this trial is it doesn't have to be.

My current AGM is also on its way to failing after 3 years in the 200. I naively thought I could make a small change in chemistry and get more longevity (at a high cost, too!) It's a different chemistry, so let's set it aside, but I figure the LTO when sussed will last 30+ years. You can take it from car to car. It's a paradigm shift.

When the stodgy old OEMs (aside from BMW) figure out that they can save 30 lbs at a vehicle corner just by changing the regulator in their alternator for different voltages and speccing a slightly more costly battery, I think adoption will be quite high. I bet at OEM volume the cost isn't even that much of a difference.

I don't need a house batt, I have a small 'solar gen' which is perfectly fine, but if I can use the stock space for the house it becomes at least an option. . .

 

[linuxgod]

Which 280Ah batt did you get? I might one day upgrade my camper as it's still on 2x 6V FLA golf cart batts.

If I'm being honest, I've not really needed more battery than this in my camper. It's around 220Ah rated, and 150Ah usable, and a camper has tons more electrical than the even built out overlanding vehicles.

This one:

204.93€ 38% OFF|Liitokala 3.2V 30Ah 50Ah 105Ah 150Ah 173Ah 200Ah LiFePO4 Accu Diy 12V 24V Motorfiets Elektrische Auto solar Omvormer Batterij|Oplaadbare Batterijen| - AliExpress

Smarter Shopping, Better Living! Aliexpress.com

a.aliexpress.com

4 batteries, technically, though in series that’s 12.8V nominal I also ordered a Daly 100A BMS. We’ll see what the quality is one I receive these in a week or so and have a chance to balance them and then try to deplete the capacity.

FWIW I run on a 100Ah wet cell now, and it’s pretty rare I need more than about 50%, so this is ridiculous overkill capacity... for now. But given the cost for the BMS, shipping, etc the cost to build a 150Ah-200Ah was maybe $150 less, and the Amazon cost of a knock off 200Ah was more than I’ll spend building this, never mind the retail cost of a 100Ah Battle Born or similar.

 

[Sandroad]

Just had a chance to read through this thread. For some reason it reminded me of the many times the 6V battery in my ‘46 Jeep would be dead and I’d have to start it by coasting down the driveway and popping the clutch.

 

[grinchy]

Sadly the LTO cells were never delivered (or at least not delivered to me). Project on indefinite hold.

 

[linuxgod]

Sadly the LTO cells were never delivered (or at least not delivered to me). Project on indefinite hold.

I can’t speak to the LTO cells but I’ve been using my LiFePO4 cells in the camper for the last 3 weeks and they’ve been working awesomely. I’ve not dipped below 69% of 280Ah. The final battery pack I built is pretty close to a group 31 size. I think you could build a 200Ah LFP for $500-600

LFP isn’t ideal for cold weather but as an aux battery it’d work well

 

[grinchy]

For those that want an off the shelf LTO battery, Ioxus had a line. Here is an example:

XS Power/Ioxus IX-3160 60Ah Lithium LTO Battery 10,000 RMS handling 14v

IX-3160 by XS Power An Audio Apex Exclusive! Max Amperage 500a Rated for 10-12k each Over 2500 cranking amps Rugged Group 31 casing Max recommended charge of 16.2 AGM Charger Compatible Internally Balanced 1 year warranty

caraudiobargain.com

Ioxus went on to be bought by XSPower, which is the other retail US vendor for LTO cells.

I think at $900 it is very expensive, but a 40AH LTO diy would cost around $500 at today’s prices, and the smaller 40ah XSPower retail 6 cell packs are $700.

It certainly could be the last battery you ever buy, good for many thousands of cycles and lightweight, but also a high cost of entry.

My AGM is getting closer to dead, will be buying a SLA soon.

 

[Phoenix666]

Registered just for this post!
Having experimented with LTO, something that I would add is that the discharge and charge curves in the last few volts have so little capacity I found charging from 2.0 to 2.6 volts gave so close to 100% capacity, I never bothered going outside those margins. 2.4v max charge is also in the 90% range. This is relevant for the 5 v 6 question, 6 cells gives 95%+ between 12v and 15.6v, 5 gives 10v to 13v. I personally think the former (6) is better, even if you lose a little on the top end.

I wouldn't worry about the alternator going full tilt unless you are using a fair amount of power while the vehicle is not on.

As for capacity, I would see if you can fit these (not affiliated, have dealt with them before, better than Ali) 6 pack - Toshiba 2.3v 20ah LTO - https://batteryhookup.com/products/6-pack-toshiba-2-3v-20ah-lto, perhaps in 2p (if it fits). (If the link gets stripped, search for Battery Hookup LTO)

In answer to all those that are saying why?

Because you can, and the lifetime cost is WAY lower than any lead acid replacement. This should last 20 years (then have reduced capacity) whereas AGM last 3, if not less. The cost of the DCDC charger plus $350US, so perhaps $400US. Can you buy a AGM battery for less than $60US? Even if you could, isn't it worth your time to not change batteries 7 times instead of once?

The lifetime cost + convenience is a total winner.

The only issue is the alternator burning out, and there is a solution to that.

 

[grinchy]

Registered just for this post!
Having experimented with LTO, something that I would add is that the discharge and charge curves in the last few volts have so little capacity I found charging from 2.0 to 2.6 volts gave so close to 100% capacity, I never bothered going outside those margins. 2.4v max charge is also in the 90% range. This is relevant for the 5 v 6 question, 6 cells gives 95%+ between 12v and 15.6v, 5 gives 10v to 13v. I personally think the former (6) is better, even if you lose a little on the top end.

I wouldn't worry about the alternator going full tilt unless you are using a fair amount of power while the vehicle is not on.

As for capacity, I would see if you can fit these (not affiliated, have dealt with them before, better than Ali) 6 pack - Toshiba 2.3v 20ah LTO - https://batteryhookup.com/products/6-pack-toshiba-2-3v-20ah-lto, perhaps in 2p (if it fits). (If the link gets stripped, search for Battery Hookup LTO)

In answer to all those that are saying why?

Because you can, and the lifetime cost is WAY lower than any lead acid replacement. This should last 20 years (then have reduced capacity) whereas AGM last 3, if not less. The cost of the DCDC charger plus $350US, so perhaps $400US. Can you buy a AGM battery for less than $60US? Even if you could, isn't it worth your time to not change batteries 7 times instead of once?

The lifetime cost + convenience is a total winner.

The only issue is the alternator burning out, and there is a solution to that.

It would be nice if there was a consistent stock. For a while there were BMW (I think) envelope backs on the 2nd hand market, but these seem to have dried up. And the cylindrical cells are just a tough form factor for a high density location like under the hood.

It certainly pays to have a search routine thru the reseller sites to find stock, like Battery Hookup.

 

[Phoenix666]

For those that want an off the shelf LTO battery, Ioxus had a line. Here is an example:

XS Power/Ioxus IX-3160 60Ah Lithium LTO Battery 10,000 RMS handling 14v

IX-3160 by XS Power An Audio Apex Exclusive! Max Amperage 500a Rated for 10-12k each Over 2500 cranking amps Rugged Group 31 casing Max recommended charge of 16.2 AGM Charger Compatible Internally Balanced 1 year warranty

caraudiobargain.com

Ioxus went on to be bought by XSPower, which is the other retail US vendor for LTO cells.

I think at $900 it is very expensive, but a 40AH LTO diy would cost around $500 at today’s prices, and the smaller 40ah XSPower retail 6 cell packs are $700.

It certainly could be the last battery you ever buy, good for many thousands of cycles and lightweight, but also a high cost of entry.

My AGM is getting closer to dead, will be buying a SLA soon.

The one thing I look at when browsing LTO premades, is the warranty. If they don't offer more than an AGM, then chances are they are junk. A 1 year warranty? I would avoid that like the plague.

 

[Shadze]

Registered just for this post!
Having experimented with LTO, something that I would add is that the discharge and charge curves in the last few volts have so little capacity I found charging from 2.0 to 2.6 volts gave so close to 100% capacity, I never bothered going outside those margins. 2.4v max charge is also in the 90% range. This is relevant for the 5 v 6 question, 6 cells gives 95%+ between 12v and 15.6v, 5 gives 10v to 13v. I personally think the former (6) is better, even if you lose a little on the top end.

I wouldn't worry about the alternator going full tilt unless you are using a fair amount of power while the vehicle is not on.

As for capacity, I would see if you can fit these (not affiliated, have dealt with them before, better than Ali) 6 pack - Toshiba 2.3v 20ah LTO - https://batteryhookup.com/products/6-pack-toshiba-2-3v-20ah-lto, perhaps in 2p (if it fits). (If the link gets stripped, search for Battery Hookup LTO)

In answer to all those that are saying why?

Because you can, and the lifetime cost is WAY lower than any lead acid replacement. This should last 20 years (then have reduced capacity) whereas AGM last 3, if not less. The cost of the DCDC charger plus $350US, so perhaps $400US. Can you buy a AGM battery for less than $60US? Even if you could, isn't it worth your time to not change batteries 7 times instead of once?

The lifetime cost + convenience is a total winner.

The only issue is the alternator burning out, and there is a solution to that.

I just built a battery for my motorcycle using those cells. Is the DCDC charger necessary
I threw the cells together with a balancer and called it a day.

 

[ubguessin]

A more realistic full power alternator test. The alternator (90A Bosch) is running full tilt for around 15 min+. It gets very hot (180C+ at the windings), but continues to work fine.



Now how long would it run 100% on a 40Ah LTO battery from flat to full at full tilt (140A effective charge out of a 180A alternator -> 3.5C) - roughly 17 min. Probably would burn out the alternator after doing this a few times . . .

To many of these videos bashing alternators charging a LI battery never has another fan blowing air across the alternator as would happen while driving down the road. So how bad is it really to charge a LI battery off of our alternators in that environment?

 

[grinchy]

The issue is that these newer chemistries have far more AH to recharge as they can fully discharge safely, and can take the recharge at 10c or even more. So it can easily toast a tool like an alternator which is designed for a limited overhead chemistry like sla. It is however an issue on large banks of sla, like a marine battery stack. Toasted Alts are well known in that community, as are the workarounds. Basically you have to limit the alternator to a Range that is safe and stay out of the thermal overload danger zone. It’s just a different control circuit, or use a battery charger instead.

 

[Phoenix666]

I have ordered 35ah LTO's and they are on the slow boat from China. I will be testing a 6s as a car replacement, no BMS, just an active balancer.

The alt can't overcharge it, as they have a higher cut off voltage than the alt produces. LTO don't get hurt too much over-discharging (if that can even happen)
So yeah, stay tuned in a month or so and see if I cook my car!

 

[grinchy]

Should be a fun time. I’m sad mine fell off the boat. I hope yours don’t!

 

[kcjaz]

I wonder how well a water cooled alternator would cope?

 

[grinchy]

I wonder how well a water cooled alternator would cope?

it could help, but I suspect that conditions exist that could still thermal overload additional cooling ; the true solution is to cap the current draw of the battery during recharge to a sane amount. It can be as easy as putting a small resistance into the circuit, something like 1 ohm. I did some calcs and had settled on something like 4" of M6 stainless steel. This small inefficiency has very little effect on the performance of the battery under load, but caps the current draw under recharge enough to keep the alternator whole (not that I tested it . . .)

Other solutions exist as well, foremost a separate DC DC charger.

 

[Phoenix666]

Small update. I have spoken to someone from youtube who has tried 5s and 6s LTO and says 5s works better. Admittedly if your alternator is 14.5v 5s works out at almost exactly the top rating of 5s, and you would get 75%(ish) charge on 6s. Their testing shows the 5s is much better. I suspect this is due to voltage drop more than anything else, but it is something I will be experimenting with. Still another month+ before I get the cells, so will report back in then.

I would prefer to go 6s for longevity..

 

[Phoenix666]

They are almost here! Attached and linked (if I can) is a graph of the discharge curve of a 10ah I was discharging at 5A. I have been using this as an example of why 2.25v to 2.6v is optimal, anything outside of that is negligible. 5s is thus 11.25 - 13v, 6s 13.5 - 15.6.
Keeping in mind that the max voltage of LTO is 2.85v 5s gives 14.25v, uncomfortably close to overcharging.


Any suggestions/testing you would like done, please say so!

 

[TeCKis300]

They are almost here! Attached and linked (if I can) is a graph of the discharge curve of a 10ah I was discharging at 5A. I have been using this as an example of why 2.25v to 2.6v is optimal, anything outside of that is negligible. 5s is thus 11.25 - 13v, 6s 13.5 - 15.6.
Keeping in mind that the max voltage of LTO is 2.85v 5s gives 14.25v, uncomfortably close to overcharging.


Any suggestions/testing you would like done, please say so!

View attachment 3007330

I'm all for hacking but I just don't get the why. It's like shoehorning in a solution that is a compromise to the original system design.

LTO just aren't great for 12V systems because of the voltage mismatch. Either too high or too low. Risk overtaxing the native 12V system, or too low and either way are a compromise to capacity. Then a 35Ah LTO is ~1/3rd of the original group 27 battery capacity. It's often said for a FLA, only use half the capacity. The reality is that there is still utility of the full amount, built in emergency reserves if you will. Just that using more half capacity (regularly) may trade life to some minor degree. With such a small LTO battery the likelihood of being stranded is still much higher. Then considering the overload risk to the alternator for a battery in a low state of charge.

It's designed as a system. A great battery in a system designed for a different chemistry....makes for an objectively worse system.


Since we're talking about alternative batteries, meet this bad boy. Not for the car but an RV. The cruiser gets a high quality FLA.

 

[grinchy]

I have an high amp / start amps rated LTO bms if you want. Send me a pm.