B

benbell4140

Well Known Member
Hello group, I'm at the point in RV8 fuse construction where I need to choose a battery location. Looking for some suggestions.

O360 with fixed pitch..( probably catto 3 blade)
Steam IFR panel
Grove gear
I weigh around 185

Anyone with a similar setup?

Thanks in advance!
 
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For your light(er) engine and light prop, the firewall battery mount is probably best.
If you change your mind and want a constant speed prop, then you would definitely want to put the battery in the back.

An interesting compromise for some people is to put the battery in the bottom of the front baggage well. Its not suggested in the kit, but it can be a good choice. Trade-offs include surrendering some good baggage space, but it is less nose-heavy, keeps the cables short.

Hope that helps,
 
Ditto what Steve said

With your setup I image fwd mounted battery would be fine. My airplane has the hartzell with the angle valve engine and inverted oil, so I put everything plus the kitchen sink in the back of my airplane - battery included. I haven't weighed my so we'll see how I did.
 
Fun Choice

I put mine in the forward baggage compartment and ran a trickle charger up just aft of the baggage door. I can open the door and connect a charger without having to do anything else. It also makes the engine compartment less cluttered. I would also look at getting the McMasters spring arm for the forward baggage door which works great. Good luck and these are the decisions that you will enjoy making because it means you are that much closer to getting in the air, and that it is "your" airplane, blue skies


Tim Fitzpatrick
N308TF
Waiting on paper work to fly
 
Thanks for all the tips guys, I think I like the forward baggage idea. I'm currently riveting fuse skins and while reading ahead the battery box came up. I'm trying to build as light as possible so I think the forward battery location will suit me fine. By the way these match hole kits are awesome. I started on the fuse kit a little over 2 months ago and we are already riveting skins. Amazing!!

Thanks.
 
Baggage floor

I am building a -8A and I should not have a CG problem light prop and gear are much further back than the -8. I did use the front baggage floor area and made it an Electronics and Equipment bay (E&E Bay). I made a floor extension so now the baggage area is all one floor and the E&E bay is covered, I too plan a plug just inside the baggage area to allow hook up of a batter tender when away from the plane.

I had bought the rear battery wire harness kit from Van's but did not like running more stuff up under the floor. I talked with Scott at Van's about the -8A demo plane and he said the battery up front is fine for my setup and not required in the back. I went further and have magnesium wheels, this is more to safe weight that goes into my IFR panel! Not sure I will be happy with the final W&B, might have to go with a polished paint scheme to save a few more pounds.

Advantages:

Battery in a more hospitable environment
Less stuff on the firewall
Shorter wire runs
Helps CG some

Disadvantage:

Lost some baggage space but with the way I travel the plane has more than enough left over.

Pictures everyone like pictures.

Top view in the middle of wiring

htvjae.jpg


View from side with baggage wall removed, wiring mostly done

23iyryb.jpg


Baggage wall when removed, sitting on the bench, I am adding a power outlet.

1z21sms.jpg
 
Battery

Ben:

If you are married and plan to travel, I think I would use the firewall location. You'd (well maybe you wouldn't) be surprised how much your spouse can drag to the hangar for a trip.

If you do use the fwd. baggage comp. for the battery and other electrical eqpt., you probably can't fit anything else in there for fear of electrical shorts etc., etc.

At times you need the fwd. baggage compt. to adjust for Weight and Ballance.

Then too; in the future, there's a chance you might want to install a removable smoke oil tank in there.
 
I am married and we do plan on taking trips in the 8 one day. The problem is... If I let her bring everything she "needs" I would need to buy a cessna caravan!!! But anyway I think I'd rather the battery on the floor in the baggage area rather than the firewall. Simple maintenance.

Thanks
 
benbell4140 said:
I am married and we do plan on taking trips in the 8 one day. The problem is... If I let her bring everything she "needs" I would need to buy a cessna caravan!!!
Click to expand...

A good friend of mine and his wife have a small british sports car with very little trunk space. He cured her of the "bringing three weeks worth of clothing for a one night trip" problem by buying one suitcase that essentially filled the trunk. After he put his few things in the suitcase he told her she could bring anything she wanted as long is it fit the remaining space.
 
where and which battery

I am at the stage of thinking about batteries. I have an 8 with a hartzel constant speed and a 180hp lycoming. I was planning to use the bottom of the front baggage compartment. What I need to know is

1/ Does this sound like a good location for that combination of engine and prop?

2/ Which battery do most builders use?

Thanks

Jim
 
Battery

Jim,

You need to put the battery in the back, if not for Ben's light prop I would say the same for his, the 8 and 8A flies faster and land better with weight in the back when solo. An 0360 and CS prop will demand the battery in the back. You can do a search on this subject and find a ton of information.

Pat
RV8
RV8A
RV10







Jimboscr said:
I am at the stage of thinking about batteries. I have an 8 with a hartzel constant speed and a 180hp lycoming. I was planning to use the bottom of the front baggage compartment. What I need to know is

1/ Does this sound like a good location for that combination of engine and prop?

2/ Which battery do most builders use?

Thanks

Jim
Click to expand...
 
But anyway I think I'd rather the battery on the floor in the baggage area rather than the firewall. Simple maintenance.
Click to expand...
I can assure you the firewall will be far simpler for Maint ;)

Cowlings will be off every ~50hr check, and your Batt Maint I cannot see much more than checking every year "it is still there" :) Which is easily done cowlings off, and it is open to you and at a convenient working height...

As opposed to holding a baggage door open, maybe flying round in the wind, that is up over a lip ~4'+ in the air, and then with head and arms down 2-3' in a dark small baggage compartment :eek:

Our battery is in the rear location, which would be a pain for Maint, except what "Maint" does a sealed battery need? The compartment comes apart each year to check the elevator linkages.

I can only add as above, it would be a real shame to lose the front/side baggage area. The flexibility of the RV-8 for baggage carrying is great, and I cannot see a need to lose some of this for battery / electrics that the majority of builders / designs perfectly adequately put where Vans intended :eek:

Your choice of course :confused:

I am at the stage of thinking about batteries. I have an 8 with a hartzel constant speed and a 180hp lycoming. I was planning to use the bottom of the front baggage compartment. What I need to know is
1/ Does this sound like a good location for that combination of engine and prop? No - might well be out of Fwd CG limit solo. Hartzell Prop - Battery in Back IMHO
2/ Which battery do most builders use? Odssey PC680
Click to expand...

Andy
RV-8 G-HILZ
RV8tors
 
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Jimboscr said:
I am at the stage of thinking about batteries. I have an 8 with a hartzel constant speed and a 180hp lycoming. I was planning to use the bottom of the front baggage compartment. What I need to know is

1/ Does this sound like a good location for that combination of engine and prop?

2/ Which battery do most builders use?

Thanks

Jim
Click to expand...

I've got an O360-A1A and Hartzell and put my battery (an Odyessey PC680) on the firewall. This has worked fine, although I usually put some weight in the baggage compartment when solo (otherwise I'm close to the forward CG limit). I can carry just about anyone who will fit into the rear seat without threatening the aft limit. However, doing it again I'd probably go with the aft battery location because most of my flying is solo and handling is better with CG closer to mid-range.

Note that moving the battery from the firewall to the forward baggage compartment actually makes very little difference in CG, about 0.07" by my calculation (assuming the PC680).
 
Firewall for me

0-360 with FP Sensenich though. I keep heat on my engine during winter months so my battery is staying warm along with my engine. Not sure that it will make a difference, time will tell.

Randy
8A
 
Jimboscr said:
I am at the stage of thinking about batteries. I have an 8 with a hartzel constant speed and a 180hp lycoming. I was planning to use the bottom of the front baggage compartment. What I need to know is

1/ Does this sound like a good location for that combination of engine and prop?

2/ Which battery do most builders use?

Thanks

Jim
Click to expand...




My thoughts:

There are quite a few -8's flying with this same engine/prop combination, and most of them are in the forward third of the CG envelope when solo. The further forward you get the CG, the more "solid" the airplane feels, the further aft, the lighter it becomes. Back when people used heavy lead/acid batteries, you could make quite a difference in CG with battery location, but with a huge number using PC680's, it is not as big a deal....however, a way is won with individuals, not a single army, so everything you can move aft will give you a lighter control feel - assuming that like most RV-8 pilots, your flying will be done mostly solo. (No matter what you think now, unless you are far out on th bell-shaped curve, this will be how it works out). I like the aft battery location, and look at the battery whenever I have to look at the controls behind the baggage compartment - usually at annual.

AS for the forward location, I personally have found that the little right side part of the forward baggage compartment is incredibly useful for the canopy cover, tools, oil, etc that always live in the airplane. If you travel a lot, it makes a difference! If you are local-only, out-and-back type flyer, then it may not be so important - but ask folks who have been flying for a couple years, not those who THINK they know how they are going to use the space once they finish.

All of the solutions work by the way - my thoughts are just to add data for your consideration.

Paul
 
location of battery

Some good food for thought. I am very happy to consider as many peoples experiences as possible. The more information the better, it allows me to try and make a much more considered decision. Thanks for all who have replied so far.

Cheers

Jim
 
Battery

One additional item. If you put the battery in the back (the correct location if solo most of the time) you can, and I have built a plexiglass window in the top of the hat box. That allows you to hold the back seat forward and with a flashlight inspect your battery, bellcrank and the auto pilot servo in about 60 seconds. No cowlings to remove and also as Paul said, that forward baggage space is very useful space. I actually put a hinged door on the top of the right side hole that seperated it into two baggage areas. You also need a hinged door in the top of the forward baggage for simple access to the brake lines, removing that panel is a pain in the $%#@.

Pat
 
One thing to consider:
You state that you are building as light as possible.
Firewall mount battery has the shortest run of the heaviest wire.
My battery is in the back (alternate engines are heavy) and the heavy gauge wire for the starter is pretty heavy. It all adds up.
It's just something to think about.
 
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