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Popjinx
11-10-2005, 07:58 PM
What do we need to keep in mind when designing and building a battery tray or battery compartment for a lipo? How much foam cushioning is considered enough around the battery itself (if any) while not impeding cooling. I know the battery(s) need to be secured where they can't be punctured. Is velcro on balsa or plastic enough? It would be nice to get an idea of what you guys are doing.

I switched to brushless/lipo after my initiation into rc (Aerobird). I'm flying a modified Aspire EP and a fxhobbies Bandit. I've been lucky and not had any hard landings or crashes, YET. When it happens, it would be nice to give the battery a chance of survival.

If this subject has been "beaten up" already, please accept my apology.

Thanks in advance,
Mike

NotAnAceYet
11-10-2005, 08:19 PM
I use a velcro square on the back of the Lipo - attached to fuse - then another thin strap of velcro around it. Just a little extra safety so the Lipo won't "eject" from the fuse during a "less than perfect" landing.

Larry

ForestCam
11-10-2005, 08:34 PM
I use a piece of industrial strength velcro about the same size as the batt (approx. 1.5" x 2.5").

You'd be suprised just how much holding power velcro has. I once worked at an apartment complex that had a big screen in the rec room with a VCR on top of it. The VCR was held in place by a piece of velcro that covered the entire bottom. When the VCR eventually died I had to use two flatbars and a long kitchen knife to remove it and ended up bending the VCR's chassis quite a bit.:D

Popjinx
11-10-2005, 08:58 PM
I've tried the velcro. I put a piece the length of the battery pack in my Aspire one time and was worried that I'd damage that dang-pricey TP 4200mAh pack prying it out. I kept charging it in the plane for a month out of fear (LOL)!

My new fxhobbies Bandit has a 2-1/2" fuse (square pvc gutter pipe, actually) I'll be mounting the battery packs in. I'm just trying to take precautions and give the batteries some cushion if anyone thinks it's necessary. These are 2 Falcon 5000mAh 3s2p packs wired in series (AXI 412018 motor). If I ruin these doing something stupid other than driving the plane into the ground, there will be gnashing lf teeth. I've learned some expensive "operator error" lessons with less expensive batteries. I wanna just fly with these; not over-amp them, not leave them plugged into the esc till they fade into paper weights.....

hoppy
11-10-2005, 09:06 PM
If possible, I use a Velcro strap-in method. With some scrap pieces of depron, make a loose fitting cage for the battery and attach a Velcro strap across the top to hold the pack in. I don't like to do a lot of pulling on the packs if I can help it.

A small piece of spongy foam in the front part of the compartment will help cushion the impact if....

Flywhat2
06-05-2011, 10:03 PM
Hi Folks,
I like to hold batteries in place with velcro. Can I use hot glue to glue one part of velcro to a LiPo battery ? or is the heat too much for the batt?
Thanks much, Fly

icarus46
06-12-2011, 07:42 AM
Hi Folks,
I like to hold batteries in place with velcro. Can I use hot glue to glue one part of velcro to a LiPo battery ? or is the heat too much for the batt?
Thanks much, Fly
Just clean the batt case with alcohol and cotton and stick the velcro to it. If it comes loose later I just use a small amount of epoxy.

Davethebluessinger
07-27-2011, 04:30 PM
If the standard adhesive on the velcro isn't man enough, I use some contact adhesive like UHU or (UK) Evo Stik.
Clean the lipo first then apply a thin coat of glue to the case and the same to the sticky side of the velcro then let it dry til it's touch dry. then carefully align the two parts before allowing them to touch because you're only gonna get one go! :eek:
Remember to use UHU POR if it's a foamie!:D

On my swift II I recut the mounting holes for servos and the lipo into the top face of the wing and made the Lipo a really snug fit, I lined the bottom of the cavity with correx for strength and glued it into place. Next I got hold of some 2mm stainless wire and pushed it straight through the foam appx 3/4" either side of the cavity. On the underside I bent the wire at rightangles and put a small reinforcing piece of correx between the wire and the bottom surface, I hot glued and then taped over it. Then I bent the wires protruding through the top surface into a hooked loops. I use doubled elastic bands (dropped by the postman) to stretch over the lipo and pull it firmly into place. Never lost a lipo yet despite a few less than perfect landings!:D
On the Mini Swift I did the same thing except I used a small garden tie type velcro strip glued under the correx liner and protruding out back and front so it can be wrapped tightly around a 500mAh lipo. Again, no problems with ejected batteries after a lot of flights.

road king 97
07-27-2011, 06:03 PM
I epoxy my velcro down on the bottom of my planes most have a platform i made ,the velcro sticks good to the battery packs so i dont glue it .I then put a strap also just to make sure it wont come loose . I also build small boxes to hold my reciever to the bottom or side so it wont come loose and pull wires out ,velcro on thos too. I use zip ties on the recievers also . Only zip ties on my escs to hold in place only so it does not overheat . I never use foam around any of them because of heat build up that may happen. I also use velcro on my servo wires to stick to the side of my fuse and the sticky tape holds the connecter together also so it wont come appart . Makes a neat looking inside with every thing in its place . joe

TheLastDom
09-14-2011, 11:52 PM
Velcro seems like the best option. I would think that foam would just add some nasty fumes to a fire if there was a bad crash.

rcers
09-15-2011, 12:13 AM
Nothing you can do with totally protect a LiPo in a crash. So dont' worry too much about that.

Velcro works well for small packs.

For large packs I use a small strip of velcro to keep it from sliding back or forth. Then I use seat belts to secure the pack in the plane. I use the velcro straps for this. They work well for larger packs.

I seat belt everything over 3s 2200 after having a slightly larger pack eject on a rather violent snap. :)

Mike

road king 97
09-15-2011, 12:47 AM
Nothing you can do with totally protect a LiPo in a crash. So dont' worry too much about that.

Velcro works well for small packs.

For large packs I use a small strip of velcro to keep it from sliding back or forth. Then I use seat belts to secure the pack in the plane. I use the velcro straps for this. They work well for larger packs.

I seat belt everything over 3s 2200 after having a slightly larger pack eject on a rather violent snap. :)

Mike I try to strap my small packs down to and velcro not to protect the battery but to stop it from going out the front of my plane in a sudden stop . Heavy objects can cause alot of damage . joe

tobydogs
09-15-2011, 03:30 AM
for the larger kits and kits with tight quarters to stash lipos[Sig hog bipe,GP RV-40,GP extra 300s,tower uproar,Sig cobra,Herr Pitts special,mini telemaster,Herr j3cub,Herr mini sport's x2,Sig aqua star.aquastar skimmer]i built battery compartments that have thumb screw latches and are air cooled by design. all these birds still exist in the hanger and i did build threads a on most of them or can provide pictures.

the 3dhs aj slick,airfoils profile yak ,gaunli p47 use Velcro the battery and the fuse/with a velcro strap to secure it. i do use velcro straps to secure the 6cell batts in the larger birds to keep them from shifting forward or back even a little.[2 3cell packs rubber banded together] and and the velcro fuzzy side to cushion the batts in there compartments.

one reason i enjoy building compartments is most of the builds were meant for glow power/fuel tank areas to fill which weighs more than my ep motors and esc's....i rarely have to add lead weight to get cg as batteries are easy to position during the build process.

just a few pictures of compartments...the last 2 pictures are of the slick#1 and the hole in the battery after the crash. the first hog bipe also was destroyed and the batteries were ruined. hog # 2 is better built.

solentlife
09-15-2011, 12:44 PM
I find that a lot of parkflyers etc. like my ME109 are a bit thin in the fuselage where batterys / gear go ... especially over wing. Relying on wing being mounted and strengthening fueslage at that point.

So - I developed a trick ... many of us have old Frequent flyer cards / non-security plastic cards that expire. These make excellent 'trays' to epoxy down onto compartment floor / foam to add a bit of strength. The second advantage is the surface being hard plastic takes velcro / double tape adhesive better than the foam or other material of the model.

So card fixed in plane. Velcro pad on battery and corresponding other in plane. I then put a small wad either side of battery to make it more firm as velcro is not absolute and allows movement. The wad is a lot smaller then the battery length etc. as I believe in having maximum air around my battery to keep it cool.

I would never wrap it in foam as we used to do with NiCD / NiMH packs in models ...

Look at a helicopter LiPo ... velcro pad to keep in place and a velcro strap tight around to make sure it stays in place and doesn't move while flying ... watch em 3D and you'll see that has to be secure ! Nothing else.

I'd also certainly not start glueing stuff to the LiPo with epoxy etc. unless you want pack to be permament !