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asymptonic

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Yeah, I was just looking over their tables and boggling at the wrong-math of their module/voltage calculations.

brian_

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Yeah, I was just looking over their tables and boggling at the wrong-math of their module/voltage calculations.
It's okay once you realize that they are using different electrical groupings of the same cells, and are listing the parallel cell group as if it is one cell of larger capacity.

asymptonic

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Yeah, I understood what they were going for, but it just didn't match my expectations. This line in particular irritated me. 20 modules at 22v nominal for a Hyper9 HV results in way over the allowed max voltage for the inverter without paralleling the modules:

brian_

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Yeah, I understood what they were going for, but it just didn't match my expectations. This line in particular irritated me. 20 modules at 22v nominal for a Hyper9 HV results in way over the allowed max voltage for the inverter without paralleling the modules:

View attachment 126443
That example combination is
• 71.0 kWh
• 20 modules
• 40 cells (actually cell groups) in series
• 480 Ah
• 22.2 V nominal module voltage
• 25.2 V maximum module voltage
• 148 V nominal pack voltage
• 168 V maximum pack voltage
• 940 lb or 428 kg
This is from the examples which are supposed to be using 3.55 kWh modules, with 71.0. kWh in 20 modules they are 3.55 kWh each. With 40S in 20 modules they are 2S modules, which do have 480 Ah capacity. That's the #11 module type:
11) OXDP 3.55kWh 7.4vdc 2s Spec Order
The module description specifies a suitable voltage (3.7 V/cell x 2 cells = 7.4 V), but the example has the wrong module voltage - presumably just a typo. 40S @ 3.7 V/cell or 20 modules in series @ 7.4 V/module is the right voltage (148 V nominal, 168 V peak), and that's suitable for HyPer 9HV.

The 56.8 kWh line for 16 of the 3.55 kWh 2S modules has the same module voltage error and there's at least one other line with a similar error.

asymptonic

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Yep, I feel like they had an intern put together a spreadsheet. Either way doesn't build a ton of confidence beyond the fact that there is clearly some decent fabrication engineering surrounding whatever their cell supply is. The 'Energy' modules are pretty obviously generic but they spent more time in their engineering and marketing on the 'power' modules. They are appealing for the more varied voltages available and varied sizes, but..

brian_

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Yep, I feel like they had an intern put together a spreadsheet. Either way doesn't build a ton of confidence...
I just imported their example configurations (for all three Power module sizes: 2.66, 3.55, and 5.3 kWh) to a spreadsheet and ran some checks: the only errors are that the module voltages for types 8 (3.55 kWh 16S) and 11 (3.55 kWh 2S) are incorrectly stated in the example table, in every instance of those modules - that's almost half of the 3.55 kWh examples. The other values (total pack voltage, Ah capacity, number of cells in series, and energy for the stated number of the appropriate module) are all correct (meaning consistent with module specs) even for these configurations.

... there is clearly some decent fabrication engineering surrounding whatever their cell supply is. The 'Energy' modules are pretty obviously generic but they spent more time in their engineering and marketing on the 'power' modules. They are appealing for the more varied voltages available and varied sizes, but..
I agree that it is a systematically assembled range of module options from a single cell size and corresponding set of module stack components.

brian_

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In sorting through the example configurations, I noticed that they are all listed at no more than 1800 A peak current, although with the larger capacities (240 Ah and up, resulting from 8 or more of their 30 Ah cells in parallel) more than that would be expected for the cells; lower capacities are rated at 8C peak current. There must be an interconnection wiring or device limit at 1800 A. I assume that this is not an issue for the vast majority of builders.

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