Guru
Joined: 08/02/2015
Location: New ZealandPosts: 1255
| Posted: 03:09am 17 Mar 2026 |
Here is the first cut for the individual cell modules, each pcb 44x33mm, so 6 fit on a 100x100 board. The layout closely follows the conceptual drawing, with additional input cell short protection resistors R7/8, these are non critical as there is no voltage divider on Lifepo4 cells, I will prob use 3k3 1%. Two extra leds, each in series with the read and Load opto's indicate when a board is being addressed or balancing load activated.
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The CPU board 280x93mm hosts the 16 cell modules, with a expansion port for another 16, or more, as its serial driven with output buffering on the control wires. The 4 small relays provide isolated low current contacts for "Balancing, Pre-Charge, High Volts, On Load"; these are also serial driven using a TPIC6C595 power shift register, The fan output is for a small 120mm cooling fan sitting above the 16 load resistors.
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As I don't have a full schematic for this, will so some more checks and send the gerbers off today. Hopefully it will be quicker to build and take up less space than the previous version.
Cheers
Mike
Edited 2026-03-17 13:17 by Solar Mike