What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Stainless steel EarthX battery box?

sritchie

Well Known Member
Hey all,

Does anyone know of a place that sells stainless steel battery boxes that will fit the EarthX ETX680 or ETX900 batteries? I'm planning on mounting two batteries on the firewall and want to avoid the aluminum battery boxes that they sell.

Thanks!
 
Much higher temperature resistance with stainless steel. As for a reasonably priced solution that didn't offset all the weight reduction of using the battery, I never found one 12-18 mos ago when I was searching. Would be interested if one could be found though.
 
Last edited:
Got it, that's good to know. I guess if a fire breaks out then the battery's toast anyway and I'll have to trust the rest of the fire protection to keep my now-loose batteries from causing too much damage as they careen around the cowling!
 
Hey all,

Does anyone know of a place that sells stainless steel battery boxes that will fit the EarthX ETX680 or ETX900 batteries? I'm planning on mounting two batteries on the firewall and want to avoid the aluminum battery boxes that they sell.

Thanks!

I don't know of any ready made boxes, but check with Scherer Metals, 3518 Larimer St., 303-295-2412. They do a lot of the architectural stainless in the Front Range area. I am pretty sure that they can build one for you.
 
Or - don't mount the battery(s) on the engine side of the firewall. Problem solved and other problems avoided.

Carl

When I installed an LiFePO4 battery and performed an FMEA to assess the risks, mounting the battery outside the cockpit/passenger compartment was required to mitigate the risks associated with an outgassing battery. Not sure I'd want to have something that could spew toxic fumes inside with me unless it was enclosed and vented externally...which is easily done from the engine side of the firewall.
 
I'm curious. Why do you want to avoid the aluminum boxes?

You are probably right, aluminum should be ok, but sealed for venting gases outside the cowl or cabin. Aluminum melting is 1200F or so and the thermal runaway temps of LiFeP (LFP below) is just over 780F (~400C).
Here is a comparison of some technologies temperature during an induced ramp and resulting thermal runaway from a government report. In a contained box, the lack of oxygen should not set the plastic case on fire and just melt and smoke.

DCtELuc--nTT9AgmB7IiGIm8QkohO60Az17artmwpGa83Fi41zKTx4FBo0bSMNRdTbzGP27muECk6jlT_wGo5YMKzHlLTfh-9VAV4eDjgk3J_YKVstiip2WHuja_4E7o-HArCsNTa7ajUIgiNoktCIIpEYm1WG0eAjGSlyfbRov3dUfs_ksxd_mZtxvMchUR_2iV6XP9iF4ttyiCQBDRxWDfYCq7O9dPUk5vAuGKx0q_9LLS6K92otpQWIwwggroBfWyvWn66jA-b1yM58dWpVvSBGUivRBjN1aCb_KRa6243XAOOO-4Cxug-WFuJyFNiefRDNZnZ1oeELw-KnR6Y_HzX-pQZm3m5gvjuM6XR8h_U5eyam5M2w-Yd-_rKdo8J7SZ5NbuhMph66u3yxRsf-wit-o-8tob8r91sx9GUuwm08qdYf5gNWDNJVj0GCOSwahV0U_TCpfpjEI7W3A6a3tBMDbsvd-12SQUW0ds7aFKt73p1ApskCvlcnU924t4-kWPXevtdhxTsufHc_C3IDdcoD3HecGnpezT1Ria9DosYvWWYeJX0-FC9Tx-HaDr3n7cjAHk4rP56XyG2lG18c7UJggdno-C5DuSMBsV7_vZoLg2=w860-h626-no
 
Last edited:
Got it, that's good to know. I guess if a fire breaks out then the battery's toast anyway and I'll have to trust the rest of the fire protection to keep my now-loose batteries from causing too much damage as they careen around the cowling!
I was looking for a box to contain and vent a runaway battery, not protect against a fire in the engine compartment.
 
I was looking for a box to contain and vent a runaway battery, not protect against a fire in the engine compartment.


A couple of weeks ago, I purchased an EarthX battery for my -4. I suggested to one of the nice folks at EarthX that a closed/vented box for their batteries would be an excellent addition to their product line. I also suggested that the box use the same mounting hole pattern to make it easy for me to upgrade...

I installed the standard box yesterday and am eagerly awaiting the new one:)

Regards,
 
Battery Box!

...We are currently tooling up to make them.
Sealed, vented, stainless and virtually
flame proof. Will post photos soon.
Thanks, Allan ..:D
 
AS Aero Battery Box

Hi Allan,

I just ordered several items from you guys over the weekend and saw that you have already processed the order and it's on the way! Thank you for the amazing customer service!

Question, will you have a battery box option that allows for two EarthX batteries to be installed?

Thanks!
 
Last edited:
Hi Allan,

I just ordered several items from you guys over the weekend and saw that you have already processed the order and it's on the way! Thank you for the amazing customer service!

Question, will you have a battery box option that allows for two EarthX batteries to be installed?

Thanks!

...I am not sure if you want both in one box, or two boxes? We are still evaluating the most popular sizes Etc.
These new battery containment boxes, will be vary light, very thin stainless with snap on lids and vent. Thanks, Allan..:D
 
Last edited:
PC680 box

The ETX batteries are close enough that a couple of shims and the supplied padding should work with a PC680 box.
 
...I am not sure if you want both in one box, or two boxes? We are still evaluating the most popular sizes Etc.
These new battery containment boxes, will be vary light, very thin stainless with snap on lids and vent. Thanks, Allan..:D

Allen,

I would be interested in a two battery box for the firewall side. Sized for two PC680s would be ideal so that if replacements for EarthXs were not available while away, other batteries could be substituted.
 
When I installed an LiFePO4 battery and performed an FMEA to assess the risks, mounting the battery outside the cockpit/passenger compartment was required to mitigate the risks associated with an outgassing battery. Not sure I'd want to have something that could spew toxic fumes inside with me unless it was enclosed and vented externally...which is easily done from the engine side of the firewall.

I offer that engaging in design decisions to mitigate against this risk is good reason to rethink this battery for airplane application.

Carl
 
Risk assessment and mitigation identification is a sound engineering principle.

And it's something done on every aircraft, on virtually every system. And it's something we should all be doing even if we choose to use "conventional" equipment.
 
I offer that engaging in design decisions to mitigate against this risk is good reason to rethink this battery for airplane application.

Carl

A little perspective. The predominant small aircraft batteries up until the 1990's was the flooded cell lead acid battery. This battery was typically enclosed in a battery box, and mostly a sealed steel battery box to deal with acid spillage and if the battery was inside the airplane, to vent flammable vapors (hydrogen) and acid fumes overboard. Flooded cell batteries were not unknown to explode from time to time, but it is a short event with little fire.

The sealed variants of lead acid batteries came about more recently removing the need for overboard venting along with concerns about acid spillage.

Turbine airplanes and helicopters, including most transport airplanes have been certified for years with Nicad batteries that are known to have thermal runaways. In fact regulations were written for certified aircraft to require temperature monitors and mitigation procedures should a battery start to runaway. They are fully enclosed in stainless steel or steel cases and vented overboard as they too vent flammable gasses, particularly when in a runaway condition. When the runaway situation first was experienced back in the 60's there were cases of the battery exploding during thermal runaways. In helicopters some had the nose of the aircraft (where the battery typically was) destroyed. Quite a serious situation

So, batteries capable of thermal failures and outgassing are nothing new. Enclosing batteries in cases to vent possible flammable vapors overboard is also nothing new.

LiFePo chemistry vents at temperatures below the flash point for the vapors, a key difference from most other Li-ion chemistries. That means that a venting event should be limited to just venting, and a properly designed case should be sealed and vent those vapors overboard. Like all batteries there is the possibility of fire if they continue to be charged, i.e. The BMS fails and the pilot fails to disconnect the battery. That fire should also be contained by the enclosure.

None of these concepts are new. We just got away from them with the sealed lead acid batteries, and going back a compromise to get a lighter battery.
 
Thanks Allan! I'm looking forward to your product. I'm thinking just one battery per box, that will give me more latitude in selecting the mounting location.

cheers!
 
ETA?

Thanks Allan! I'm looking forward to your product. I'm thinking just one battery per box, that will give me more latitude in selecting the mounting location.

cheers!

Hey Allan,

Just wanted to check back in on this thread, as I'd love to purchase two of these boxes before insulating my firewall. Do you have an ETA on the product, or at least the dimensions?

Thanks so much!
 
Back
Top