solderless power tubes for a123 batteries
 

Has anyone used these solderless power tubes from http://modelelectronicscorp.com? If so then whats the easiest way to balance the cells? Maby i could put balance wires on there some how. Any thoughts on that? Thanks

I've seen them- I wouldnt trust them as far as I could poop them out my butt.

You need solid solder joints made with good quality solder; the solderless tubes seem to use liquid paste inbetween the cells to make the electrical connections... big thumbs down on that idea.

you are probably right. They could at least make balancing tap on there batts.

It's just a guess but I'd think youd have a hard time passing these packs out your backside. However, I don't know you so maybe you have a freakish Sphincter. :surprised:

It is obvious however that you're naive about this topic. For one, you absolutley do NOT need a solder joint for a "good" electrical connection. Second, these cells have aluminum ends which seem virtually impossible to solder together unless "you" can poop a spot welder out your butt as well.

In conclusion, your opinion is noted but however dismissed due to apparent ignorance.

Yes, I have used these packs and they are great. I would use these packs exclusively if they had the same energy density as Lipo's.

Apposed to popular belief, you do NOT need to balance these cells often. People who want you to buy their balancers would have you belive this so they can sell you more products. The thing about these packs is that they can be assembled & disassembled quickly so you can check the cells individually if/when needed. I've never had to balanced a pack yet.

Neil, I want a spot welder ASAP! :lol:

Ignorant? Me? Impossible.

I appreciate you can make a pretty good electrical connection by sticking your fingers in a plug socket, but my point was that some gooey paste between heavy cells that will be josstling around isnt the best method to make a secure connection. I also know that A123 cells need special solder and flux to solder them together, but you can also get these cells with the solder tabs pre-attached (like from a dewalt pack), so soldering them into packs for rc use is a doddle with even a meager 50watt iron and ordinary lead-free solder. As for balancing- I really wanted to believe you didnt have to balance these cells very often either, one of the reason why I have 4x 6cell packs of them. Truth is though that certain charges like my BC6 wont balance charge these packs, so at the end of charge one cell alsways seem to race away to 3.6v volts whilst the others are still at only ~3.4v or so. I then have to balance the the pack at a lower charge current until all the cells are at 3.6v.

Dont know why that is, and it doesnt happen with my lipos as they all balance charge perectly fine, just seems there isnt a balance charge mode for A123 cells.

So, Im not arrogant or ignorant, as I have plenty of practical experience :yes:

Arrogant? I thought the pooping reference was kinda funny. However, Pete is a friend so I felt compeled to respond in kind.

I'm not afraid to embrace my ignorance as I'm ignorant about a great many things. Sometimes ignorance is bliss :intello:

However, I'm not ignorant about SPT packs and I can tell you from experience that they are a very good solution for rc cars. I'm not going to try and change anyones mind if they have already made it up but until you actually have experience with a product, one should take your opinion with a grain of salt. In other words, I'll trust your opinion about SPT packs just about as far as you can poop one out your butt. :lol:

Given some of the 'videos' Ive seen on the 'certain websites' (before I stopped watching in horror/disgust), I doubt I could poop them very far, but anyway...

I dunno, it just seems a rather strange solution to assembling packs, when everyother piece of advice or common knowledge points to a solid solder joint as the best way. Since these solder tubes do hold the cells securely though (assuming they are assembled with care and attention), I guess the paste could pass the current between cells okay- I wouldnt mind knowing more about the upper limits of what is do-able before losses resulting in excess heat became a factor- hot gooey liquid might tend to trickle where its not wanted and result in a possible short or loss of connection... (that didnt sound at all rude in my mind).

What video are you refering to? Care to share a link?

The silver power paste is only applied in a very small amount which results in really just a light film. I have not seen any evidence that it ever melts or runs when applied this way. I've run SPT's for years without any problems whatsoever.

Solderless connections have less resistance than soldered connections so it makes sense to avoid solder unless absolutely required. With that said, the SPT should be a more efficient pack than a soldered one. The A123 SPT is a great solution for those who would rather avoid Dewalt pack, acquisition, deconstruction, and ultimately resoldering cells in a undesirable side by side formation. Pete also sells a phantom cell so you can run an odd number of cells if desired.

The MEC tubes are the best way to make a stick pack if that's the configuaration you desire with even number of cells.

To balance a small washer is inserted inbetween cells or tiny leads out the sides of pack. Pete had the business for sale not too long ago, did someone buy it?

do use a123 or nimh with the MEC tubes

I use nimh cells with mec tubes only for 6,8,10 cells.