12V LTO 6S configuration capacity test results w/ standard 12V charger

Will Prowse

Admin
Staff member
Moderator
This test was to see the available capacity when using a standard 12V charger on a 6S configuration LTO battery pack.

First test: I set absorption till HVD, which was around 18V. Without much surprise, I pulled full capacity (20Ah). This test was to ensure that I was pulling 100% capacity at this C rate, which was .25C.
LTO.jpg

Second Test: I attached my 12V AIMS Power battery charger on the pack, and an absorption of 14.5V was reached. Then I did a capacity test.

And I only pulled 78.45% of the total capacity! Check it out:
12v charger lto.jpg


14.5V is a standard charge absorption voltage, and I am sure I could get a better results if I modified it. I just figured it would be interesting to see the measured capacity when using standard 12V charge profiles. Using a flooded cell profile with daily equalization would improve capacity test results. But if you plan to run your system with a max absorption of 14.5V, you will only pull around 80% of the total capacity.

Pretty interesting!
 

Bob B

Photon Sorcerer
Curious if you have reached any conclusions of amps in vs amps out ..... I am wondering about the efficiency of the cells.
 

Will Prowse

Admin
Staff member
Moderator
Curious if you have reached any conclusions of amps in vs amps out ..... I am wondering about the efficiency of the cells.
The efficiency is high. I can pull 96-100% capacity if I keep it under 1C. If you go over that, or use grade B cells, you will have problems. Efficiency plummets at high c rates.
 

Bob B

Photon Sorcerer
Thanks Will .... I have seen some negative reports about the LTO efficiency.
To me it just seemed counter intuitive that a cell with such low IR and ability to handle such high C rates would have poor efficiency ... nothing scientific about that sentiment though.
Glad to see some actual testing on this chemistry.

Are you doing a video for them?
 

Marinepower

Solar Enthusiast
LTO is an interesting technology but the cell voltages make it not great for storage at 12 volt nominal.

But this seems like it would be an interesting start battery for a car, RV or boat. A regular 14.4 alternator would charge a 6S pack to 75% fine and would never over charge it (assuming the cells stay in balance). It would be a cold start champion down to very low temps , last forever and provide enough storage capacity for the needs of a car even if only charged to 75%. I think negative 10C however is the lowest it can be charged, so that would be a limitation. Just a thought....
 
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