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View Full Version : LiPo charger to NiMh w/Tamiya connector questions



Stephen
10-29-2010, 08:07 PM
Hello all!

So I've been using a 12v NiMh battery with a standard male Tamiya connector, this smart charger (http://www.trossenrobotics.com/store/p/5915-Smart-Universal-Charger-for-7-2v-12v-NiMH.aspx) with a standard female Tamiya connector, and this handy-dandy on/off switch (http://www.trossenrobotics.com/p/Battery-wiring-harness.aspx) between my battery and my arbotiX board.

I'm going to purchase this LiPo battery (http://www.trossenrobotics.com/store/p/6293-3S-11-1V-2100mAh-Pro-Lite-V2-20C-LiPo-Battery.aspx) and charger (http://www.trossenrobotics.com/store/p/6431-LiPo-Balance-Charger-Starter-Kit.aspx) from TR, and I want to keep using my NiMh as a secondary/backup battery while the LiPo is charging.

From what I understand the standard Tamiya connectors are old tech, and I can't tell what the above LiPo battery and charger uses, or in general what connectors I should begin using instead. So with that I have a few questions:

1) What will I need to connect my NiMh with Tamiya connector to the new charger (I'll be traveling in a few weeks and lugging two separate chargers around seems redundant!)? Are there adapters for such connections?

2) I've found the battery wiring harness from TR to be super handy. Is there something similar for use with the new LiPo battery that anyone else here is using? Or would I just need to make one myself (using the existing wiring harness and replacing the Tamiya connector with a new/different one)?

3) Erm... will I be okay with a LiPo in my checked luggage on an international flight? What precautions, if any, should I take?

Thanks
Stephen

P.s. At some point I hope to help others more than seeking help myself! :wink:

elaughlin
10-29-2010, 08:24 PM
You can take a look at this thread that I just started about a week ago with some similar questions.

Quick Battery and Wiring Questions (http://forums.trossenrobotics.com/showthread.php?t=4431)

I asked similar questions, because I am for the first time connecting a Lipo battery with the same wiring harness and a battery charger.

lnxfergy
10-29-2010, 08:32 PM
What will I need to connect my NiMh with Tamiya connector to the new charger (I'll be traveling in a few weeks and lugging two separate chargers around seems redundant!)? Are there adapters for such connections?

I believe the Lipos ship without an attached connector. You'll want to pick up some of the T-connectors (often called "deans" connectors). I believe the charger comes with a T/Deans connector end, so mainly you'll just be attaching a female connector to both your new and old battery, and a male connector to the robot.



3) Erm... will I be okay with a LiPo in my checked luggage on an international flight? What precautions, if any, should I take?


I believe you must do them as *carry on* -- so that if they were to burst into flames the crew can access them. The TSA has regulations on LiPo (which unfortunately change from time to time) -- I would check their site for the latest information.

-Fergs

Stephen
10-29-2010, 09:33 PM
Thanks elaughlin and Fergs!

Is the T/Deans connector preferred over Tamiya? Are there other connector types I should consider, or is the T/Deans the way to go?

I ran a quick web search and it looks like one can get connector conversion cables (pre-built Deans to Tamiya for instance), but maybe this should be avoided if one type can handle a greater load than the other. I've never soldered anything and I don't have any equipment to do so just yet. And quite frankly it scares me! So I want to avoid soldering at present; I'll perhaps try my hand at this further down the road, unless of course it's unavoidable if I'm to put a Deans connector on the bare LiPo from TR.

To go the solder-less route at this time, should I use a different connector type (one that I can just crimp)?

Thanks for the tip regarding LiPo as "carry on" Fergs. I'll check the TSA website.

Cheers,
Stephen

darkback2
10-29-2010, 11:59 PM
So I recently switched from Tamiya to T and from NiMH to Lipo. I'm not drawing very much with my walkers, so I'm not too worried about it.

I see every connection as:
1) weight I don't need my walker to carry
2) a potential place where things an go wrong.

I try to have as few connections as possible. That said, off my bot I go crazy with them. While my battery is charging I can run my walker using a wall outlet. For that I have a tamiya connected to a T connector.

On the bot I just use T connectors.

I have found that Tamiya connectors are sometimes hard to plug in, and they can melt if you draw too much current through them.

DB

jes1510
10-30-2010, 12:27 AM
Deans have better current carrying capacity. Tamiya is fine though unless you are pulling a crapload of current.

lnxfergy
10-30-2010, 12:51 AM
Deans have better current carrying capacity. Tamiya is fine though unless you are pulling a crapload of current.

My only other gripe is that Tamiya connectors are more likely to shake themselves loose -- if this is robot is a walker, it's a good idea to think about things shaking themselves apart....

-Fergs

Stephen
10-30-2010, 12:09 PM
Right after posting my questions I ran a quick web search and, as has been suggested in other threads here, there's a tonne of information at a multitude of RC forums! I perhaps should have done that first before forming more sensible questions related to robot construction! :wink:

I also found many YouTube videos on basic soldering of hobbyist batteries and connectors etc. Soldering isn't so scary after all! I just need to purchase a good soldering iron. :happy:

The RC forums I've read go into great debate about Dean, Traxxas, and EC5 connectors. The EC5's seem quite popular with the RC folk. They talk about Dean being difficult to plug/unplug, but perhaps that's the point here regarding shakier walking robots over RC vehicles.

So in terms of robots, has anyone here used the RC5 connectors? Any thoughts?

As far as soldering goes, any tips on a good brand of soldering iron to buy? What else should I get for soldering battery wire/connector parts?

Thanks for all of your insight and suggestions everyone!

Cheers,
Stephen

P.s. For anyone interested here's a link to a RC forum post (CCH1978 right at top of page) which gives a brief overview of different connector types (http://www.rctech.net/forum/radio-electronics/363708-best-battery-connector-4.html).

tician
10-30-2010, 01:15 PM
If you want to go really high end and long term reliable (years of daily use) for soldering, you probably want a Weller soldering station (cheapest you'll find is $100). They are worth the investment if you plan to do a lot of soldering for a long time as all of the important parts are replaceable (tips, heating elements, irons/handles), they get up to temperature very quickly, and I believe the handles are really comfortable.

But I was cheap when purchasing, so I have a 50W station made by Velleman (VTSS5U) I got for <$20 online with a couple extra tips. It has been pushing three years of intermittent use and I have had no problems so far other than user stupidity (copper wire conducts heat very well, so watch your fingers). My only real gripe is that it uses colors instead of numbers for the temperature dial so I have no idea what it actually is temperature wise (I guess "hot enough to melt lead-free solder" is all that really matters). There are plenty of decent generic soldering stations available at various sites. However, I would recommend you stay away from the 15W firestarters as they may not have enough power to easily heat a Dean connector (they also are not a good long term investment as all tips corrode, and if you cannot replace the tip then you must toss the entire iron).

Among the accessories you will need are solder (rosin core means it has some solder flux embedded in it), maybe a tube of solder flux, and something to help hold wires/components in place while soldering (usually a set of second/helping hands (basically a couple of aligator clips on a small articulated frame), but a vise may work better for larger objects like PCBs and connectors). I'd also recommend getting a piece of scrap wood to lay on top of your work surface (if it is at all valuable) to protect it from damage while soldering. This also makes me want to recommend you have a fire extinguisher nearby just in case.

EDIT
I knew there were a few more good/great brands, I just couldn't think of the names. Aoyue is what Sparkfun uses for production, and they sell mostly Aoyue stations (both soldering and hot air rework) plus a Sparkfun branded station (Hakko?).

lnxfergy
10-30-2010, 02:21 PM
The RC forums I've read go into great debate about Dean, Traxxas, and EC5 connectors. The EC5's seem quite popular with the RC folk. They talk about Dean being difficult to plug/unplug, but perhaps that's the point here regarding shakier walking robots over RC vehicles.

The one reason I'd suggest sticking with the Deans connectors is that they are more commonly found -- if you suddenly need new ones, you can be almost certain that most local hobby shops will have them in stock. The same can't be said for some of the newer designs, which may or may not have staying power in the long run.


If you want to go really high end and long term reliable (years of daily use) for soldering, you probably want a Weller soldering station (cheapest you'll find is $100). They are worth the investment if you plan to do a lot of soldering for a long time as all of the important parts are replaceable (tips, heating elements, irons/handles), they get up to temperature very quickly, and I believe the handles are really comfortable.

Actually, I'd take a look at the Aoyue stuff -- it's half the cost of a comparable Weller most of the time and just as robust. I use my $50 Aoyue 937 (see Amazon) on a daily basis, and have had it for about 2 years now, and it's a stellar product. The stock tip is fine enough to do precision work (I regularly rework SMD chips, even the very small pitch ones), yet has the ability to do more heat-intensive soldering (such as putting on deans connectors, which I also do with the same iron). I know of many people who swear by them -- even in production houses.

-Fergs

Stephen
10-30-2010, 04:48 PM
Thanks for the recommendations tician and Fergs. I'm going to go with the Aoyue 937. Amazon sell Deans connectors too, so I'll grab some of those with the same order. With a few other bits and bobs, a LiPo and charger from TR, I should be good to go power wise. Thanks everyone!

Cheers,
Stephen