LTO (Lithium Titanate Oxide) – The Ultimate Battery for Dash-Cam parking mode (DIY)

viciouslancer said:
I though GPak found an upgraded charger that has a built-in diode - in his video https://dashcamtalk.com/forum/threads/lto-lithium-titanate-oxide-–-the-ultimate-battery-for-dash-cam-parking-mode-diy.50484/post-631154
Click to expand...
That's right, the 25A version has no reverse flow, likely due to built-in reverse current protection.
It also has adjustable low input voltage protection to protect the car battery when the ignition is on but the engine is not running.

For some reason the AliExpress link is broken (see next post), it seems to be some kind of AliExpress glitch because many other links are broken too.
I also noticed that the prices of many items are now higher in some cases significantly.
 
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viciouslancer said:
@GPak

Do you have a full updated build of materials (aside from batteries)? I took a look through the thread and components were upgraded/removed.

I think it's
  • batteries
  • Charger + BMS
  • UPS (optional)
  • XT60 connector with ACC direct to car battery
  • time-delay relay
Click to expand...
Here is the list of components for my updated 5S LTO battery.
Unfortunately some of the links are not working now, sometimes they come back, but you also can search by product description:

Battery – Toshiba SCiB, 20Ah, LTO Cells (also available on AliExpress)
https://batteryhookup.com/products/2-3v-20ah-lto-prismatic-cell

BMS – Smart 4-8S 40A, Active Balance BMS, (JKBMS)
https://www.aliexpress.us/item/3256..._main.179.68be1802BfLCY6&gatewayAdapt=glo2usa

Charge controller – TZT YF-BKT60V25A 25A 9-60V Automatic Buck Boost Module Buck Boost Converter Step up down Converter
https://www.aliexpress.us/item/3256..._main.221.240c18026nX6AV&gatewayAdapt=glo2usa

Relay – Time Delay Relay 10 sec, 5 pin, 12V, 30A, SPDT
https://www.amazon.com/gp/B0744HSF8P
Fuse – Inline 12V 14AWG
https://www.amazon.com/gp/B0CBZ8XVJ3
UPS – DC 12V 8A Dual-Sources Automatic Transfer Switches Controller Battery UPS Power Supply Module
https://www.aliexpress.us/item/3256..._main.189.68be1802BfLCY6&gatewayAdapt=glo2usa

Battery Monitor – Supnova 7-100V Digital Battery Capacity Voltage monitor ($15)
https://www.amazon.com/gp/B0B2ZQRYFX

Power Connector – Amass xt60i Series With Signal 2 + 1 High Current Gold-plated Aviation Plug Male Female Connector XT60IE-M XT60I-F XT60IPW-M
Amass XT60i series with Signal 2+1 High Current Gold-plated

Connector – Gintooyun 3 Pin Terminal
https://www.amazon.com/gp/B0B1DDG79D

For the 5S configuration I used Box – Aluminum Electronic Enclosures 85x145x250mm (tight fit, requires some mod)
https://www.amazon.com/gp/B07WQ3CG78
or
I would prefer this one, it is just slightly bigger for better fit and it is Black
80x16x260 DIY Electronic Housing junction Box Metal Aluminum Case

---------------------
For the 6S configuration I am working with Box - Aluminum Case PCB Junctio Box Electrical Accessory Sand Black Heat Dissipation for GPRS
https://www.aliexpress.us/item/3256..._main.210.1ab01802wlF5nx&gatewayAdapt=glo2usa
 
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GPak said:
That's right, the 25A version has no reverse flow, likely due to built-in reverse current protection.
It also has adjustable low input voltage protection to protect the car battery when the ignition is on but the engine is not running.

For some reason the AliExpress link is broken (see next post), it seems to be some kind of AliExpress glitch because many other links are broken too.
I also noticed that the prices of many items are now higher in some cases significantly.
Click to expand...
Yes, AliExpress doesn't seem as cheap as before. Also, unfortunately for me, some of your links don't ship to Canada, and when I find another listing it's 1.5-2x more.

Have you thought about 3D printing cases?
 
GPak said:
I also noticed that the prices of many items are now higher in some cases significantly.
Click to expand...
I was surprised by this as well. The backflow diode I picked up a while ago was priced at $4 and was offered at $2. That same board is now $8. We’re talking small prices still, but that’s a 4x price increase in just a few months.
 
viciouslancer said:
Have you thought about 3D printing cases?
Click to expand...
The case and other 3D printed parts such as clamps, brackets, reteiners, etc., would be perfect since they would be specifically designed for the given project.
The material should be selected so it is fire-resistant and to ensure the temperature range.
Unfortunately, I do not have a 3D printer.
 
Here is a link to using a Voltage Sensing Relay (VSR) with a DIY LFP battery in my son's car.
This VSR can be used with any battery, including LTO and even Power Stations.

GPak

Post in thread 'LFP (LiFePo4) Battery for Parking, 192Wh (DIY)'

Upgrade - Added Voltage Sensitive Relay (VSR), see attached video for explanation.

So now we have 2 redundant Relays in series, the VSR and the original one in the battery, which is not optimal, but a simple upgrade.

A better solution could be to use this Voltage Sensing Relay instead of the regular Relay inside the Battery without having to use the ACC input to control charging, if there was enough space.

  • Like
 
I proof tested the 6S LTO Battery for use as a Jump Starter and it works as expected.
The jump starter cable has alligator clips on one end and a spark proof XT90 connector on the other end, and the wire gauge is 10AWG.
The wires don't get hot for short cranking, I cranked the car several times in a row to check this.
The maximum current surge was around 330A for a very short period of time.
I only have a 200A fuse in a small form factor that should fit in the box, I'm not sure if it has some delay and will handle the surge, if not I can connect two fuses in parallel.
For this test I meant to use the second multi-meter as a voltmeter to measure voltage drop, but I messed up and used it as a second clamp meter. :banghead:


*************
Next I will proof test Solar charging.
The battery should automatically switch from regular 12VDC charging to a Solar charging once ignition is turned off.
For this I am using an MPPT charge controller.
It is less efficient than the more efficient charge controller I have, however the latter is not an MPPT and will not charge at the low current typical of a small solar panel.
 
I figured that would work, given the output capacity of the batteries. Thanks for the proof of concept! What surprises me is that 10g wire was sufficient for carrying enough current, though it was just a short duration…
 
Many of 'Jump Start' cables available on aliexpress and amazon are 10 AWG, especially the short ones, including the one I used.
However, I was also worried about the 10 AWG wires, but was hoping for an even shorter cable length inside the box and a very short cranking time.
Also, the battery terminals are not heavy duty sized either.
Larger cables would be definitely better but it is more difficult to work with and fit in a small box.
 
GPak said:
Many of 'Jump Start' cables available on aliexpress and amazon are 10 AWG
Click to expand...
Wow- I’ve never gone looking for jumper cables, so I was not aware many were so “thin.” I have a set of jumper cables in the garage and while I’m not sure of their gauge, they are WAY thicker than 10ga. Have to go and dig them out now to see if they are marked…

Let’s just say that if I was building my own set of cables, I’d be looking for much heavier wire! But, I tend to appreciate over engineering things to a level not found in many commercial grade products.
 
Ok, let’s file that under things I’ve never looked closely at before! I just dug out my set of jumper cables and it looks like they, too, are 10g - maybe 8g at best, but that feels generous. Guess I was fooled by the over blown thickness of the wire insulator, but looking at where the wire emerges from the sheath and is crimped to the terminal connector, it’s much thinner than I anticipated. It’s also a pi$$ poor crimp job, too! Yikes…

Looks like many of the cheaper ones on Amazon are copper coated aluminum, too. I’d much rather have copper conductors.
 
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I installed a 200A fuse and tested my 6S LTO Battery again and it worked.
Voltage drop is really minimal from about 15.32V to about 13.68V or about 1.64V at 300A !! (see attached screenshot)
A 200A fuse is not designed to withstand a continuous 300A load, however, a very short-term 300A spike will not cause the 200A fuse to blow.
Later I may try a 150A or even 100A fuse.

 

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Here is the wire I used, and Amazon description:
https://www.amazon.com/gp/B017TGYW3S
- High Quality Ultra Flexible Soft Silicone Rubber Copper Wire! Super Low Impedance, Highly Efficient!
- They are constructed with premium silicone rubber insulation. High temperature resistance 200 degree C, Low temperature resistance in extreme cold -60 degree C. Rated Voltage: 600

10AWG is the largest size wire with terminals best suited for the given 20Ah LTO cell posts and the fuse box, and flexible enough to fit inside the box.
I also ordered 8AWG just in case, but it requires larger terminals that don't fit easily into the LTO posts, and the fuses kit.
https://www.amazon.com/gp/B074P4HSF2

Fuse kit with 200A fuse
https://www.amazon.com/gp/B0CJZMN4FX

Ring Terminals are also Tinned Couper:
Terminals Kit, Crimp Connector Assortment

XT90 Anti-Spark Connecter with Battery Alligator Clamps, 10AWG Cable.
https://www.aliexpress.us/item/3256..._main.126.7cf11802yDKO0R&gatewayAdapt=glo2usa
 
WOW! That's REALLY impressive current output from the 6S battery pack with only 1.6v drop! I should have bought a few more of these batteries while they were available... Amazing stuff!
 
EricSan said:
they are WAY thicker than 10ga
Click to expand...
Back in my car stereo days i had cables in my car, at least as big as garden hose, and the fuse for stuff, 160 A at the source if my memory goop serve me right, smaller for the individual AMPs
 
BTW if i was Toshiba demoing the durability of my cells, i would for sure have one attached by a samurai with his sword. 🙂
 
To conclude the jump starter part,
I decided to test if my LTO 5S, 20Ah battery would work as a jump starter... and it doesn't.
I'm sure the 5S configuration has adequate output voltage and it will work as a jump starter as well, but higher Ah rated LTO cells are needed.

I guess 5S, 20Ah LTO might still work as a jump starter for smaller engines or in parallel with a car battery if it is not completely dead, but I have neither to test.

 
Hmm… that looks like what happens with a depleted main battery, a few clicks and no action, so my guess is the voltage sag under load is too much for the starter motor. 5*2.6v - 1.6 sag under load works out to about 11.4v.

Those XT90 connectors look like they are rated at 40A continuous and 90A peak. Not a good long-term connector for this purpose, but should work in a pinch 🙂
 
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