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Originally Posted by suneel112
Doing some research for a project, I came accross Saphion U-Charge batteries (from Valence)...A lighter battery is the Ultralife UBI-2590 UBI-2590 . |
One should read further and check out the safety warning at
http://www.ultralifebatteries.com/wh...recautions.pdf
You will note in this document that these batteries should never be subjected to discharge above the rated current, dropping or sudden or repitive shocks. The result may be heat, explosion, or fire.
It is also interesting to look closely at the discharge curves compared to SLA. For one, check that the batteries being compared are the same size but not the same current rating so the curves are slewed to make the Li battery look way better. Note also the discharge for the Li batteries runs out to a point and then takes a nose dive while the SLA battery slowly drops the terminal voltage. The final thing to note is the graph only shows performance down to 10 volts not the eight that we are more interested in. Using this type of battery in one of our matches would produce a dead robot when the battery is discharged instead of a marginally operational robot. A check of the original spec sheet will also inform you of the need for special charging and special protection circuitry as part of the battery to protect the user from exceding the safe discharge ratings.
I like the use of solar chargers, or human powered chargers. A robot that was using one of those methods should be given a couple of extra points in a match where they are using a battery charged by one of these methods.