DIY Tesla Battery pack // Build Updates

[ebenbayer]

Hi Everyone,

I'm planning out a DIY Tesla battery pack (40kWh comprised of 8 5 kWh modules.) [edit: built, see beneath]

My current outback inverters won't cut it with a cut out voltage of 42 volts (which would be ~70% SOC on these Lion packs).

I'm considering a new build with 1 or 2 stacked https://www.altestore.com/store/inverters/off-grid-inverters/3000-to-7000-watts/magnum-energy-mspae-4448-4400-watt-48v-invertercharger-p8110/ Magnum's as they claim an input voltage of down to 36 (I won't go that low to protect packs, but need to get to 40, 38 would be nice on occasion).

Based on reading this forum and elsewhere these seem to have a good reputation.

an other inverters folks would recommend consideration? (need to get to 8 KWH eventually).

I'm of course waiting on the Midnite Inverters!!! But not sure how much longer I will put this project off.

Thanks for any suggestions.

E

[ebenbayer]

I'm going to proceed with a test setup. Ill try and update this thread with results since I didn't see a similar one;

BMS: Orion BMS 2
Pack: 2 Model S Tesla Battery Modules 5.2 kWh, 2s1p configuration to start (~48 V); Plan to go to 2s4p if this works well (40 kWH pack)
Inverter: Magnum Energy 48 V
Charger: Classic 200

Will use Classic for low and high voltage cut off points; BMS with back up shut off.

[ebenbayer]

Hi All,

for those interested.

I completed this install using 10 Tesla modules at 5.1 KWh each for a ~50 KWh bank (42 usable).

I ended up using a controller from evtv to interface directly with the Tesla BMS; this provides cut off in high and low voltage scenarios as a safety. 
Great kit.

of course, easy to reconfigure my existing classics to charge these units safely.

For abundance of caution, I also purchased and placed the units in a fire cabinet.

This system came in around 300$/kwh (batteries + bms).

I was able to use existing outback inverters (they will go down to 36 V via setting changes in MATE)

Overall, super pleased with system performance.

[ZoNiE]

Hi,
Where did you get the Tesla Modules? I have a Rav4 EV with a 40KWh Tesla Battery and will need to replace it someday.

[ebenbayer]

Ebay as a start. Then a local scrapyard / tear down shop (~local = 2-3 hrs away).

Good luck!