JST to Deans adapter safe for main power source?

[LostFedExMan]

Hey guys I have a 1/10 scale RS10 XT. I just did dome mad mods to it and now have less space for a battery. So I bought some new batteries in all sorts of sizes to see what'll fit best.

Well problem is, I didn't pay enough attention when buying the batteries and half of them came with the little JST connector that you see in the picture below

http://ep.yimg.com/ca/I/yhst-6219634..._2261_36069241

Some of the batteries are 3 cell, some are 2 cell and they are 500MAH, 800MAH, 1000MAH and 1300MAH.

My question is, is it safe to buy (or make) a JST to Deans adapter (Dean Male to JST Female Adapter DMLJST) and power my crawler with these little 500-800MAH 2-3 cell batteries? My main concern is the wires coming off the small batteries are quite small in comparison to the regular wires on larger batteries. Would this cause an issue or be a possible hazzard?

Thanks for any help

[808DA6]

Whats the electronics spec on your crawler? I'd be very concerned about pulling too much current for those wires.

[LostFedExMan]

I found this picture on RC Universe about the specs of the ESC



I'm not exactly sure what you mean by specs. But the Crawler is MOA, 2 35T 390 motors. Comes with a 7.2V Nimh. I've been running a 3S lipo for 6 months no problem, so I'm not worried about the ESC or crawler being able to handle the 11.4V.

The thing is, if those batteries are 3S, what's the difference in running 11.4V to a smaller RC Helicopter in comparison to a larger RC Crawler. Yes the electronic specs aren't the same, but 11.4V is 11.4V isn't it? If the wires that came on the battery are able to handle 11.4V would it matter if I made an adapter to run the same amount of power from a thinner gauge wire to a larger gauge wire?

Does that make sense or am I talking to myself?... lol

Thanks for the response

[Pete Attryde]

The problem isn't the voltage, it's the current (amps). thinner the wire the lower the amps it can handle, To much current will melt the insulation on the wires and could cause a short circuit or worse case a fire.

That said 390 motors shouldn't pull a huge amount of current so may be ok.

Pete.

[LostFedExMan]

Cool thanks Pete I appreciate that, and it makes sense. I don't know a whole lot about AMP's. Can I just run it for 5 min and see if the wires get warm/hot and judge if it's safe by that you think?

The guy in this video
RS10XT Update #2 - LiPo! - YouTube
is pretty much doing exactly what I'm asking about, running his RS10 on a lipo with the smaller leads, he just soldered on a different connector instead of using an adapter. But he is only using 2S. Would there be a huge difference in current using 3S?

Thanks again

[Erik D_lux]

I dont think the adapter would be an issue and I definitely dont think the Deans would be the issue. I think the only thing you would be concerned with is if the JST itself holds up.

FWIW, I have been running JST plugs without any sort of adapter on my MOA for coming up on a year. I have not had a single issue and they never even get warm. I only run 450mah 25c batteries so I am not sure how much a bigger battery will matter.

JST on my Berg is one of the better things I have done.

[rangercat23]

I use those batteries in my 1.9 comp truck, I just cut off the old connector and solder on deans.
The batteries in my 2.2 pro have the same gauge wire, that truck has dual tekin fxr's and dual tekin 35 turn motors.

You should be safe, if you are running 390 size motors.

[SINister]

Nothing wrong with the batts they will hold up fine. I changed over to the smaller JST connecter on my XR10 over a year ago with no issues. I run the sky 800 and gens ace 450 with the same wire and JST connecters.

[LostFedExMan]

Kick ass thanks for the info! That's exactly what I needed to hear. If it can handle your 540 motors my 390's shouldn't be an issue.

[LostFedExMan]

Just wanted to let everyone know everything works great! I am loving the smaller batteries, I was running these massive 3000 mah 3 cell's just for the run times. But MAN I wish I would have switched to the smaller batteries sooner. Only downside is swapping out and charging more batteries. But that's not a big deal to me.

Thanks again guys

[rangercat23]

glad to hear!!!

One of the good things about smaller batteries is they take less time to charge.

[Charlie-III]

Originally Posted by rangercat23

glad to hear!!!

One of the good things about smaller batteries is they take less time to charge.

At a "1C rate" all batteries take ~1 hour to charge.

[KBrog]

Yup, just make or buy a adapter, it works fine. I made an adapter and run it on my 2.2 S rig. Works fine no problems at all.

[Calderwood]

Originally Posted by Charlie-III

At a "1C rate" all batteries take ~1 hour to charge.

Who charges at 1c? With bigger batteries most people are limited by how many amps the charger is capable of. This is not so much the case with smaller batteries so the 5-10c charge rates that modern lipos are capable of is more attainable.

[Charlie-III]

Originally Posted by nigels_world

Who charges at 1C? With bigger batteries most people are limited by how many amps the charger is capable of. This is not so much the case with smaller batteries so the 5-10c charge rates that modern LiPO's are capable of is more attainable.

I charge at "1C", for what it's worth.

I never stated you couldn't charge at higher rates, I just stated what I stated.

While you can charge at higher rates with pretty much any battery, if you add up the total charge time vs. mah charged, the difference is small.

Charge 10 500mah packs at high rate vs. 1 5000mah pack at high rate, total charge time is similar. Yes, when the 1st small pack is done you can run while the 2nd is charging.
I will give you that.

Not arguing, just commenting.