Maximum Tesla S battery fluid pressure

[GyroGypsy]

This is a great idea. Although I suspect the vacuum will decrease quite swiftly. I was hoping to maintain 30" hg vacuum continuously while applying 1 bar or 15 psi of water flow. There may be a water separator that can be used?

 

[GyroGypsy]

I pulled 25" vacuum through a modified air tank and flow was restored. Thanks for the great idea. I now get about 1 LPM with 15 psi fluid pressure directly connected to a single module in either direction.

Meanwhile I still need original question answered!!!!

 

[noenegdod]

Good to hear!

I have nothing on the battery pressure question. Sorry.

 

[curiouscarbon]

glad to hear flow restored ?

 

[Geomz]

I pulled 25" vacuum through a modified air tank and flow was restored. Thanks for the great idea. I now get about 1 LPM with 15 psi fluid pressure directly connected to a single module in either direction.

Meanwhile I still need original question answered!!!!

@GyroGypsy, according to the 057Tech website specs, ( https://057tech.com/products/battery_modules ) those batteries are rated to around 0.25GPM @2PSI Max! That seems ridiculously low to me, but Jason Hughes has quite the experience and reputation with these modules.
I came here looking for the same info, as I want to pump fluid through my units as well. But I don’t know what is “safe” to do so. And I do want to use the G48 coolant designed for them —to minimize any potential for corrosion.

 

[linuxkidd]

Sorry for reviving this older thread...
I have experienced corrosion flow reduction on multiple modules ( 10'ish modules now, used across multiple installs ). @GyroGypsy wondering if you figured out a way to remove the corrosion and restore higher flow rates?

It's interesting, one set of modules has only been in use a couple of years and is experiencing as much flow reduction as another set running for more than 4 years. Maybe Tesla changed the material used in the fluid channels?
I'd love to get flow restored, otherwise, I'll have to switch to heating pads or similar..

Thanks!

 

[GyroGypsy]

Hi @linuxkidd - bet I can guess your occupation, or avocation!

This project has been moving slowly. Getting no further Tesla information, I abandoned the liquid heating system :^(, installed four Facon CW-ST725 7x25" 12V heating pads with internal thermostats, one on each side of each battery. I had attached each to a .020 aluminum sheet for better heat dispersion, but the internal thermostats would short-duty cycle and not heat long enough to be effective.

I have since removed the internal pad thermostats, added JanFcal High thermal conductivity pads (AMZN), a LM YN DC 24V digital thermostat (AMZN), and a Thornwave.com PowerMon which tracks and stores current usage. Sadly I had to remove 1/2" of battery box insulation to fit in the four conductive pads which offer direct contact, yet cushion against the thin Tesla plastic battery case.

I will start by using the supplied thermostat temperature sensor, which will measure a single point "average" battery box air temperature. Both batteries use two Electrodacus.com BMS which monitors one of two internal Tesla battery temperature sensors per battery, and plan to adjust the digital thermostat reading to best track these. I may later attempt using one of the remaining two Tesla temperature sensors to control the new digital thermostat if K.I.S.S. does not work. The Electrodacus BMS customer service and hardware has been awesome to work with, and I am confident that a thermal shutdown will occur via the BMS when the internal Tesla temperature sensors indicate. Sadly the BMS shuts down but charging and discharging when this happens, and must be overridden if you want to continue discharge during cold times. Sadly our Colorado artic blast has stopped, still sub-freezing nights, but I can always overnight at the nearby mountains for near zero night testing.

Waiting for some final deliveries, and have two weeks of traveling upcoming quickly. I will post test results when done.

 

[linuxkidd]

Hi @GyroGypsy .. Thanks for the update. I've reached out to UltraHeat ( they're known for RV tank heaters, but they have done a LOT more than that.. including LiPo battery heaters ). They're a bit more specialized by application since they can tweak the output temperature of their heating material to match the purpose. RV tank heaters ( and similar ) output a very high temperature compared to what should be applied to LiPo packs. They're working up an estimate for me on two types of heat panels:
1 - End panels with some amount of foam backing to reflect the heat toward the battery
2 - Center panels without any foam, designed to be sandwiched between the battery modules.

I should hear more on this in the next day or two and I'll update here on what they come back with.

I'll be controlling this based on the Tesla temperature sensors ( I interfaced directly to the Tesla BMB to query cell voltages and terminal temperatures ).

I really hate that the flow channel on my modules is non-functional now. I'm tempted to sell these and buy new modules and use a different fluid. However, not dealing with fluid has it's benefits ( fewer moving parts, no risk of spill, etc ).

LK

 

[GyroGypsy]

I will check this out.

I would prefer if the fluid heater system still worked with more even temperature distribution which better averages all cells. One cheap moving part - an aquarium pump. My reservoir and pump was about six feet from the batteries, and three foot was outdoors through insulated hoses.

I won't have time to finish my pads for a couple weeks.

Keep in touch.