EARTH X under cowl ….how is battery temp ?

[Stewbronco]

Saw a very neat EARTH X install in RV3 cowl cheek…but alas will not fit RV4 cowl cheek ! …..looking at options and not too keen on in cabin install . Anyone got an RV4 with EARTH X firewall forward ? Any battery over temp problems ?
Might be talked into the vented battery in cabin but I think prefer to explore thermal battery box and blast tube on FWF install . Thanks. Stew

 

[ty1295]

I have an earth-X on my firewall in my 9, and several customers with firewall installs on 8's and 7's. Not a signle issue on any of them, except that they start so much nicer with more power.

 

[cccjbr6]

Earth X under cowl

The heat was too much for two of them so I had to buy a third one and install it inside the cabin between the sets of rudder pedals of the RV6A.

 

[DanH]

Folks, it's easy to determine temperature. One measurement is better than all the opinions in the world.

An LM34 (degrees F) or LM35 (degrees C) works with 12V main bus power and can be read directly from an ordinary digital voltmeter. Put one on the end of a three-wire conductor and place it anywhere for a quick read.

 

[jclark]

What Dan said ...+

Folks, it's easy to determine temperature. One measurement is better than all the opinions in the world.

An LM34 (degrees F) or LM35 (degrees C) works with 12V main bus power and can be read directly from an ordinary digital voltmeter. Put one on the end of a three-wire conductor and place it anywhere for a quick read.

Measured Temps at the battery under cowl of RV8 some time ago. All below threshold.

Also, have you considered the 680C (as in Compact)?
I would think that they would fit in the cheeks.

 

[David Paule]

I saw an RV-4 that had its battery in the cowl cheek, FWF, I think behind the aft RH cylinder. That's what gave me the idea for putting mine in the cowl cheek extension.

I think that the RV-4, with the same but longer cowl than an RV-3, has skinnier extensions. I used RV-4 cheek extensions but had to extend the edges to fit my RV-3 cowl - and then, thankfully, the 680C fit. Even so, it's a snug fit.

Dave

 

[Stewbronco]

Definitely Skinner cowl cheeks

Yes Dave ...it was your cheek install that I referred to ...very nice and you are correct,much smaller cross section cheek extensions on the -4 . Room FWF is occupied on both sides ...Raven inverted canister on RH side and oil cooler on LH side ( could squeeze 680 C in there but hot air from cooler obviously counter productive ) ....may just live with the 10 lb weight salving of going to PC680 from old Concorde in stick location. Many thanks. Stew

 

[moespeeds]

Keep in mind that EarthX makes a vented version for interior installations. They say it could meltdown under your seat, and you'd never know as all gasses are vented overboard via tubes and a bulkhead fitting.

 

[climberrn]

My EFIS (Dynon) has provisions for 2 additional thermocouples. Placed one zip tied to the battery box. Have an audible warning set if it gets too hot, as in early detection of engine fire. Looking back on Savvy, most flights 30-35C. The literature I found from EarthX says 60C continuous is acceptable and 65C for up to 30 minute’s during operation. Ok for up to 85C after shutdown, but not in operation. 7A, right upper firewall, standard Vans box.

Saw an insulated box on their site that has provisions for a blast tube.

 

[DanH]

Keep in mind that EarthX makes a vented version for interior installations. They say it could meltdown under your seat, and you'd never know as all gasses are vented overboard via tubes and a bulkhead fitting.

Hope so, because I have two going inside on a 7A.

My EFIS (Dynon) has provisions for 2 additional thermocouples. Placed one zip tied to the battery box....Looking back on Savvy, most flights 30-35C.

Calibration? 35C is way less than typical. I'd call summer exit air temperatures less than 50C to be unusual. I've recorded exit air temps as high as 109C.

Think of it this way. The goal is an efficient cooling system. To be efficient, we want the air mass to pick up as much heat as possible, so we can flow less of it.

Ok for up to 85C after shutdown, but not in operation. ...
Saw an insulated box on their site that has provisions for a blast tube.

Blast tube is useless after shutdown, and so the battery is hot when used for cranking.

 

[scrollF4]

Single blast tube, no problems

I run a blast tube from my rear baffle wall to the insulated stainless steel ETX900 battery box, firewall mounted behind cylinder #3. I have never measured the temps but have had ZERO temperature-related issues, even after hot summer day shutdowns.

Sorry if my response doesn't directly relate to the OP's original question.

 

[dmattmul]

Temps under the cowling

I have 2 Earth X batteries FWF one located stock location RV-14 and the other low pilot's side. (Close to the exhausts) Anti-Splat heat shields to help protect the lower battery) Blast tube on the lower battery but before EarthX made their heat shield polished chrome version. (Which I think are very, very nice) I have 2 O-ring thermocouples attached to my G3X tucked down inside the battery box's. I also have 2 strip temperature indicators attached to the top of each battery box. (Purchased from Amazon) Plans FWF battery (Upper passenger side) runs ~ 35 to 45 F over ambient once allowed to equilibrate in cruise. Lower battery runs 55 to 65 F over ambient again once allowed to equilibrate. My lower battery if I sit waiting for departure will set off the EarthX temperature warning. After I get to cruise altitude goes off. 3 years and 450 hrs. of use I have 95% ampacity left in the upper battery and 85% left in the lower one. Measuring residual ampacity, a good thing. Starter is Skytech NL and not the lightweight model. B&C primary and pad mount alternators. My plan is to change out the lower battery next conditional and the upper battery 2 years later.

 

[Stewbronco]

Many thanks

Great ....exactly the type of info I was looking for ....many thanks to all. Cheers. Stew

 

[vas4vans]

Great ....exactly the type of info I was looking for ....many thanks to all. Cheers. Stew

I have 2 Earth X batteries FWF one located stock location RV-14 and the other low pilot's side. (Close to the exhausts) Anti-Splat heat shields to help protect the lower battery) Blast tube on the lower battery but before EarthX made their heat shield polished chrome version. (Which I think are very, very nice) I have 2 O-ring thermocouples attached to my G3X tucked down inside the battery box's. I also have 2 strip temperature indicators attached to the top of each battery box. (Purchased from Amazon) Plans FWF battery (Upper passenger side) runs ~ 35 to 45 F over ambient once allowed to equilibrate in cruise. Lower battery runs 55 to 65 F over ambient again once allowed to equilibrate. My lower battery if I sit waiting for departure will set off the EarthX temperature warning. After I get to cruise altitude goes off. 3 years and 450 hrs. of use I have 95% ampacity left in the upper battery and 85% left in the lower one. Measuring residual ampacity, a good thing. Starter is Skytech NL and not the lightweight model. B&C primary and pad mount alternators. My plan is to change out the lower battery next conditional and the upper battery 2 years later.

I too have two of the ETX-900 batteries mounted FWF one down low and one up higher. When I first bought the plane a bit over a year ago, I was seeing regular messages on the EFIS from the lower battery on hot days especially when doing pattern work. Apparently the previous owner hadn't been getting those messages so EarthX sent me a replacement battery free of charge (awesome customer service!) but that didn't solve the problem.

An A&P friend (who also owns a -10) suggested a modification to send some air from a scat tube to the area around the battery and that essentially fixed the issue.

One after-note is that when I was training/practicing for my commercial checkride over the last couple of months (since's it's become hot), the message come on couple of times when practicing low-speed, high deck-angle maneuvers like slow flight and chandelles in hot conditions (90 degrees+). It did also show up on the checkride (temp was 95+) but then once the checkride and paperwork (success!) was done, I took off with the temperature at 103 degrees to fly back home and the message didn't show up again.

They do have an insulated battery box (https://earthxbatteries.com/product/bb-th-thermal-battery-box-e-case/) available in case you are particularly concerned about it. You will probably have to fashion an insulated lid for it. If things change and the message starts to come back more regularly, I would seriously think about swapping out my lightweight box for it.

 

[DanH]

Insulation slows the rate of temperature change. It will not prevent the battery from heating. It merely heats more slowly. When hot, an insulated battery will also cool more slowly.

 

[Dustyone]

Data is a good thing

I fitted an EarthX insulated battery box to an RV-10 and as others have pointed out the hottest temp reached was after shut down.

However with the insulated EarthX Battery box, the battery operating temps were never exceeded with a good margin.

Air-Con equipped RV-10 with EarthX battery installed on the firewall.

Battery box installed and tested with digital 4 channel Temp Meter,

The results showed after test flying that the battery remained within operating testing ranges even after shut down.

Blue : Cowl Temp at blast tube above battery
Orange: Inside battery case against the battery front face about half way down
Yellow : Inside battery case underneath the battery

You can see that the cowl inside temperature at this location peaked at about 75 Deg C ( 167Deg F )after shut down but the battery only reached 58 Deg C (136Deg F) which is below the EarthX Storage Temp of 70 Deg C and below the battery max operating temp of 60 Deg C.

 

[vas4vans]

I fitted an EarthX insulated battery box to an RV-10 and as others have pointed out the hottest temp reached was after shut down.

However with the insulated EarthX Battery box, the battery operating temps were never exceeded with a good margin.
......
You can see that the cowl inside temperature at this location peaked at about 75 Deg C ( 167Deg F )after shut down but the battery only reached 58 Deg C (136Deg F) which is below the EarthX Storage Temp of 70 Deg C and below the battery max operating temp of 60 Deg C.

Hi Ashley, what is your setup to get these temperature measurements?

Thanks.