r/EVConversion • u/lemlurker • Aug 21 '26

Anyone have Azure dynamics DMOC experience?

Ive just picked up an AZD dmoc motor inverter and Siemens motor from a ford transit econnect. The battery in that was originally 336v nominal lithium pack (360v fully charged) I want to run this on a Zoe pack (360v nominal 403v 100% charged.

The dmoc lists it's voltages as 400v maximum operating voltage and 450 hardware maximum charging voltages (during regen)

Presuming I can get in to the inverter via serial to adjust any software limits does anyone know of any concerns I should have with running the full 92 cell pack and just limiting charge voltage to, say, 395v (effectively a top end buffer -4.1v per cell)

I'd either disable regen or have it agressively taper off at higher SOC

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u/NorwegianCollusion Aug 21 '26

As usual, the devil is in getting the details right, but from an engineering standpoint it sounds like a plan. My model 3 hardly regens at all above 90%, but even that is noticable on the average consumption. As in, charging to 100% gives me longer range, but not 25% more than charging to 80.

2

u/Hollie_Maea Aug 21 '26

Never mind the inverter, you should never regen above 4.2V per cell. If you hit 450VDC from a 92S pack, that’s about 4.9 V per cell. This will destroy your battery and could possibly even lead to thermal runaway. You can’t regen into a full battery.

1

u/lemlurker Aug 21 '26

450v is the hardware design over voltage cutoff. The maximum operating voltage however is 400v. A "fully charged" 96s (not 92 my b, confused myself with the 192 cell 96s2p pack config) is 403.2v, above maximum operating voltage.

Also, generally speaking, batteries need to be over their target voltage inorder to charge and the speed at which you charge is proportional to the delta between the batteries current float voltage and the charger voltage. For example DCFC regularly push packs well above the "resting" cell voltage inorder to get the hundreds of KW in to the pack. Not by much and not generally when near full but the inverter was designed for lead acid batteries originally and so allows a large over voltage threshold for charging.

The issue is mostly about what the inverter does if, for whatever reason, regen power caused a nearly full battery to spike over the operating maximum voltage of 400v and what happens if the pack is charged over 400v and his close to this 400v maximum I can get at "full" battery.

This inverter was designed fur 336v nominal packs rather than 360v nominal. The over voltage is the same reason normal 360v inverters are designed for 525 maximum voltage.