In need a battery pro...

[Brian_BigSquidRC]

Hey guys,

I thought I'd give making my own receiver packs a try. Seems a lot cheaper, and you can get some good batteries. So I got a box.. and figure it would take me a few trys to get it right...

Well..After trashing 3 packs.. I'm looking for help/suggestions. I'm making 5 cell hump packs.
The first one seemed to last the longest... got a few charges out of it.. then it just leaked.
The second, I was happy with my soldering and started to charge it. I was keeping a eye on it, and would reach over and feel it every few min to make sure it wasn't getting hot. These are 1200mah cells.
I decided to try charging it at 1.3 because at 1.1 it seemed to take forever and I never got a full charge.. well it was doing fine at 1.3 and the MAH were up where they should of been when all of a sudden.. Hisssssssss the thing was about to blow.. I unplugged it, and it was like 300 degrees! I tossed it out in the snow, where it melted a big section. =0
On to pack/attempt 3. All seemed ok... the volt meter shows it at all good I think, but I can't charge it for more then 100mah! I charged and discharged it a few times.. nada..
I only have like enough for one more pack =\ Anyone care to make suggestions, or give it a try.. let me know! Here I thought I'd save some $$.. and just ending up wasting them and having trouble.


Brian

(Yes I'm using rechargables )

[Michowski]

are you using rechargables? lol jk. Im sure somebody like sixcamaro can help you out. He built a few packs if i remember correctly

[FreeRideFrosty]

We built my buddies 5-cell hump pack. We never had any problems with it but I can't think of anything special that we did...

[thenewguy821]

Brian, I can help you out. I just made myself a 2400Mah Hump pack tonight. It was actually easier than I thought. I just had to make sure the Iron was clean, and keep the cells from getting too hot.

Also, With the first charge, charge it SLOW. I set mine to .1 amp. It will get a better peak, and lengthen the life of the battery. After that, future chargings for AA or 2/3A cells should be around 1.0 Amp. This keeps the heat down, and allows a better charge. When the batteries get too hot, they can false peak easier.

[Mr. Tune]

What cells are you using? How are you soldering them up, series or parallel? What charger are you using?

[FreeRideFrosty]

That is the only thing we did too... make sure you don't overheat the cells or they get damaged just as if they were to get too hot charging.

[FreeRideFrosty]

We used some no-name 2000 mah cells soldered in series I believe. Charged with a crappy wall charger...

[thenewguy821]

Sand down the tip of your iron (if it has buildup on it), re-tin the tip, Sand down the ends of the batteries. Once all that was done, I checked the "layout" of the cells, and glued them together. I then let the iron get up to temp, placed the tip on the end of the battery, and applied Solder to the battery. (DON'T put the battery bar on right away. It will take too much heat to do it all right away) I did all the ends on one side of the pack. Then DOUBLE CHECK the polarity, and where the bars will go. Set the bar (or wire) on top of the solder ball, and set the iron on top of the bar. As the solder heats, it will automatically join the bar to the battery.

[Brian_BigSquidRC]

Wow thanks for all the responses guys!

Well. I'm using the Venom 1200's. I do suck at soldering.. maybe I'm overheating them. It wouldn't surprise me in the least if that was the case.
I'm useing the Duratrax Ice Charger.. I have charged a lot of batteries with it.. never had problems till the 'homemade' packs started.

I'm doing them in Series. so if pack is facing me...
- -
+ + +

with a wire on the opposies sites of the bottom. (One on -, one on +) Which I 'think' is correct.

thenewguy821: care to take a stab with my last set so I don't ruin them all? =)

[thenewguy821]

I can do that... Let me know when, and where you want to get together. I'll show you what to do as I do it.

[Brian_BigSquidRC]

cool..
geez.. i thought I was the only one who does not sleep.. what the heck are all of you doing up?! =)

PS: had a good time at the track tonight.. met a ton of people. The Matrix is doing well, but running VERY hot. Going to call them tomorrow for suggestions.. it's super rich, and tossed on a better/new air filter.. still can't keep it under 300.

[thenewguy821]

We all were going insane on posts.... 17 pages, and 263 posts ON ONE THREAD from 9:00 to 11:30.

Sounds like there may be an air leak on the Matrix. What fuel/percentage are you running, and what plug? Also, check your Gear mesh and drivetrain for binding. If the engine is working too hard, that could keep the temps up.

[Brian_BigSquidRC]

Nothign seemed to be binding.. I'll recheck the mesh.

O'Donnels, 20%.
I'm getting a lot of smoke, which I thought air leaks cause you to run lean = no smoke.
I'm now using OS8 plugs.. but at the temps I'm running, it's eating them like cookies!

Brian

[thenewguy821]

An air leak will cause the engine to be lean, but the needles will keep the extra fuel/oil going into the engine, so it will still smoke. Check all the screws for the Head and backplate. Loosen the carb pinch bolt, and push down on the carb lightly as you tighten it back up. Start the buggy, and run it up to temp. Pick it up, and look closely around the head and backplate for bubbles, or fuel residue. This may help solve the problem.

[Brian_BigSquidRC]

Thanks again.. Hopefully I get a chance this weekend to mess with it.

Brian

[thenewguy821]

Not a problem... Worst case scenario, you may need to seal the engine. IF that is the case, some High Temp RTV and a few minutes is all it takes.

You could also TEST your Fuel tank and fuel lines. That is another source of Air leaks. Take a fresh piece of fuel tubing, connect it to the pressure tap. Take the other piece of tubing from the carb. Hold your finger over the tube that goes to the carb and blow into the pressure tube. You will hear or see if your fuel line or tank is the problem

[Tex]

an OS8 is too short of a plug for that motor. You need a standard 'long' plug (like an MC59). With the 20% (and being that OD is heavy in oil IMO) I would run a hot plug.

[thenewguy821]

OD is only 11% oil. Wouldn't he want a cold plug if the temps are too hot? I thought I heard somewhere that the colder plugs actually drop engine temp a little. ( I may be wrong about that though)

Also, I didn't know the OS8 was too short. I didn't realize that plugs were different lengths, thought the only variance was Turbo and standard

[Michowski]

no, Nitro fuel burns really cool compared to regular gasaline. The higher the nitro the cooler it burns. The purpose of a cold plug is its supposed to stay lit up easier because of how cool 30% burns. The hot plugs are supposed to take the heat better and stay lit up with a hotter gas.

[Michowski]

Any plug will work with any fuel but the colder plugs are supposed to work easier with 30% and higher the same for a hot plug and lower % fuel

[thenewguy821]

Gotcha.... < 30%=Hot Plug >30%=Cold Plug

[Michowski]

in theory it was meant to be 30% - cold plug, hot plug - 20% and lower. A colder plug burns easier then a hot with 30% fuel. Thats why a cold plug is recommended with 30% and above. Hard to explain but il talk to you about it on sunday.

[slim]

http://www.teamhelotes.com

[Tex]

a hot plug for me equals crisper throttle response and a better idling engine.

And yes 'regular' non turbo plugs come in short and long lengths. If you use a short plug in a standard button head it'll work but the temps will be unreliable and you will have loss of compression (because the plug doesn't fill the combustion chamber fully, it's like adding two shims under your cooling head)

A long plug in a head designed for short plugs will cause your piston to hit the plug...not good.

"Most" OS motors take a short plug but some like the TM's take a standard plug.

[thenewguy821]

He's got the Cen Matrix. What plug should that take? I'm just used to running McCoy's MC-9.