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

[GPak]

The first video:

 

[GPak]

Here is the video on "ANT" BMS App + bonus:

 

[GPak]

Here is the list of all components for 7S LTO Battery Pack:

Battery – Toshiba SCiB LTO Cells (7x$18=$126)
https://batteryhookup.com/products/2-3v-20ah-lto-prismatic-cell
BMS – Smart 7-16S 40A ANT BMS ($30)
https://www.aliexpress.us/item/3256..._main.187.1f7d1802FO46sr&gatewayAdapt=glo2usa
Charger – DC Adjustable Step-Up Power Supply CC-CV 1200W 20A ($14)
https://www.amazon.com/gp/B0CGTBMNJQ
Fan – Coolerguys 12V Ultra Quiet 50x10mm ($7)
https://www.amazon.com/gp/B07V5K75B2
Relay – SPDT Time delay 10s 12V 30A ($15)
https://www.amazon.com/gp/B0744HSF8P
Fuse – Inline 12V 12AWG ($6)
https://www.amazon.com/gp/B0CBZ96RS2
Buck Converter - AITRIP 2 Pack DC Converter DC 8-35V to 5V 3A 15W ($10)
https://www.amazon.com/gp/B0CNSRWTF8
Battery Monitor – Supnova 7-100V Digital Battery Capacity Voltage monitor ($15)
https://www.amazon.com/gp/B0B2ZQRYFX
Power Connector – MR60 Pigtail Wire 12AWG 100mm/3.93in Male/Female ($8)
https://www.amazon.com/gp/B0C3BKMZDK
Connector – Gintooyun 3 Pin Terminal ($5)
https://www.amazon.com/gp/B0B1DDG79D
Box - Zulkit Electronic Metal Enclosures 8.3x7.1x5.5 in / 210x180x140mm ($21)
https://www.amazon.com/gp/B09XWS2FTM
Hardware and miscellanies – ($30)

 

[GPak]

Some additional info and thoughts:

Total cost is $287 not as cheap as I originally thought but still not bad for LTO Battery, with 322Wh usable capacity and with up to 200W charge rate, including in sub-freezing temperatures.
Plus lots of fun designing, building and testing it.
Plus no need to submit ticket to manufacturer if something goes wrong, because I am the "manufacturer", and I can fix it on the fly – priceless!
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All high power wires in Battery pack are 12AWG, and they are quite difficult to work with, I believe for such a short wires 14AWG would be fine, especially if limit the max current to say 15A and 14AWG wires are much easier to work with.
I also believe now that 6S configuration is better way to go, it works with buck-boost charger and the standard hardwire kit.
All components except BMS are from Amazon, getting them from Aliexpress could considerably reduce the total price.
Building a battery pack for a specific system setup (removing the versatility) will further reduce the overall price by removing certain unnecessary components, such as the 2x5V buck converters and associated switches/connectors if only 12V output is required.
And finally, if the battery size is a concern because the need to hide it, for example, under a seat or in a hidden trunk compartment, then smaller capacity LTO cells may be used or a 4S configuration battery can be built.
That is exactly what I did for my wife’s battery pack and will soon post few videos to show the build process.
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I missed this one in my previous post:
Cigarette Lighter Power Cord - Heavy-Duty 14AWG 20A Male Plug 6ft/1.9m
https://www.amazon.com/gp/B08GFRB8VP

 

[GPak]

Here is the first video of the 4S LTO battery, showing the main components and their purpose.
Total energy capacity is 184Wh, almost double of the most dedicated dash cam batteries on the market.
It is considerably smaller in size and cost compere to 7S configuration.

 

[GPak]

And here is the second video to show how it operates.
Next I will test it in my Jeep for a couple of weeks to see how reliably it performs in everyday real world conditions.

 

[mentadent]

Would you ever build them and sell them?

 

[GPak]

Would you ever build them and sell them?

No, this is just new hobby for me, I am having a lot of fun with this batteries.
Even so components are cheap the assembly process is quite labor intensive.

I am going to distribute all these batteries and couple of suitable Power Stations I have, between my family members.
And since my family members have no plans for dash cams, I also will have to buy and install dash cams for them.
Every hobby comes with price, I guess

 

[mentadent]

Thank you for the answer.

 

[GPak]

"Houston, we have a problem"

Unfortunately I had to stop testing 4S LTO in a car due to significant radio frequency interference (RFI).
I am trying to pinpoint the cause of RFI with some of FM Radio channels.
Since RFI is only present during charging, and not present during parking, all the low power components involved in parking, such as BMS, UPS and pair of Buck Converters are beyond suspicion.
The Time Delay Relay (TDR) is the same as in 7S configuration which does not have noticeable RFI, hence TDR is also beyond suspicion.
Next, I temporary removed the Back Flow Diode to check if it has anything to do with RFI and it does not, so Diode is also beyond suspicion.
All that remains is the Charger.

At this point I am looking at 3 possible solutions:

1. Use Ferrite Cores Ring Clip-On RFI EMI Noise Suppression Filter Cable Clip
https://www.amazon.com/gp/B0CSXZWGD6

2. Use some sort of Power Supply Filtering Boards
https://www.amazon.com/gp/B0C84QLSDX
https://www.amazon.com/gp/B0B9KQW12W

3. Find a different Charger that will fit in a Box.

 

[DigitalCorpus]

Do you have an oscilloscope or are you just looking to do broad filtering? Ferrite beads also have different filtering bands and if you look around at some datasheets on mouser or digikey, you can get an idea of what size you want any how many loops your power lines should/can do through one. I wish we weren't on opposite coasts so I could roll through and assist on the diagnostic end.

 

[GPak]

Do you have an oscilloscope or are you just looking to do broad filtering? Ferrite beads also have different filtering bands and if you look around at some datasheets on mouser or digikey, you can get an idea of what size you want any how many loops your power lines should/can do through one. I wish we weren't on opposite coasts so I could roll through and assist on the diagnostic end.

No, I don’t have an oscilloscope, in my case it’s a trial and error method with help of YouTube - quite labor-intensive.
I have tried 4 different types and sizes of ferrites and toroidal core in every possible location and wires... with very limited success.
Ultimately the charger was the problem, it was faulty in addition to being poorly designed.
Luckily I had 3 different ones that I could use (thanks to the low prices on Aliexpress I always order alternatives).
The challenge was to fit inside the box, I will report the fix soon after completing short tests.

 

[GPak]

RFI issue is fixed.

I used a bunch of different size and shape and material ferrites and toroidal cores on all wires inside the box and outside on power wires for charging and power wires going to DVRs.
Tried many configurations with different loop counts and crossings where possible. Nothing really helped.
Interestingly when I was simply touching the power wires for charging or power wires going to DVRs the condition would noticeably improve, but still not acceptable.
So it was clear, it is necessary to eliminate the source of RFI – the charger itself.
The challenge was to fit the new charger in the box, the original one was the smallest one.

I have the second exact same charger, but it was also noisy (the apparent design flaw).
This one:
https://www.amazon.com/gp/B08DHNFLP3
I also have 4 more different options, but only 2 could fit.
Here is the one I installed and RFI problem is completely gone.
It has a soft start, still needs a back-flow protection diode (which I had to bend up in order to fit), but unlike the previous one, it runs so much cooler that I think the active cooling fan is overkill.
https://www.aliexpress.us/item/3256..._main.109.3e2c194dhkvfqL&gatewayAdapt=glo2usa

And pictures to show the new charger installed:

 

[TheSpanishInq]

Always nice when a puzzle gets solved