Heya JB, I use a castle BEC and wired it up like the picture. Use shrink wrap to make small sleeves that capture both power leads...keeps everything neat and together.

See pic.

Cheers

Ahh...I like that. Not sure why I didn't think of it before. I'd have to un-solder the factory battery plugs already on the battery leads to the ESC but I'd rather do that with my limited soldering skills than trying to un-solder at the ESC itself.

Did you use shrink tubing to keep the wires together...the white bands in your pic?

You don't have to unsolder the wires on the HW Xerun ESC. Just pre-tin the BEC wires, put a decent glob of solder on the tip of the iron and then solder the BEC wires to the ESC posts. Attached is a pic of what I am talking about.

BTW, don't be scared of soldering. It's easy. All you need is a good iron and to remember to pre-tin all parts, including the iron. Use the flat part of the iron tip and you are golden.

Exactly...just remember to put them on before soldering ;)

Cheers

Hideeho
I did some searching a while back for an alternative to the cc BEC & found this:
http://www.gryphon-mall.com/product.php?id_product=80
I never bought one (rx8g2 eliminated the need) but found the helicopter crowd seemed to really like them. It should fill your need quite well as it uses dip switches to set the output voltage.

I like the hard case (as long as it's not to big) and the 7.4v selectable voltage. Only gotcha I see is the specs show the lowest input voltage being a 3s pack. If that is true it will not work with those using an external BEC in short course.

I liked it too for the selectable features and the case. Good Catch on the 3S part...I'm not in short course, but I may run 2S to cut the power.

One thing I'm still a bit confused on is how to know how much current my BEC needs to support. Seems the most common are 3A, 5A, or 10A. My truck is a savage running 4s, 2150kv 4074 motor, with the hobbywing 150A esc. It only has one servo the hitec HS-645MG for steering.

Am I correct in the way I should size the BEC is to add up all the servos/devices that would need power and determine the max current they'd need? If so my one servo would not be anywhere near 3A would it? Even if I upgraded to a High Voltage and High Torque one, I don't know that it would ever go over 3A would it?

I ask this because I'm thinking of going with one of the $5 turnigy ones that's 3 or 5A and up to 6V. (I know if I get a HV servo I'd need a "bigger" BEC to supply the higher voltage).

Hideeho
I was looking at the BEC for an ebug, so I overlooked the minimum voltage. You may want to email/call them & ask about running it 2s. I would ASSUME:rolleyes: it would work for 7.4v but be limited in output to what ever the lipo provides & 7a-8a, but I could be wrong.

The amperage a system needs depends on the ESC, servo & receiver you are running. High speed, high torque servos require more amperage. Some brands (savox) of servos pull higher current than others. Some ESC's (castle, turnigy, sp) provide lower current than others. Some receivers (spektrum dsm1) pass less current to things plugged into it. That said, I am currently running a castle MMP, savox 1258, spektrum 3100 (DMS2) in a b44 with no glitchbuster & no issues with brown outs. I believe the brown out issues people have complained about are the result of DSM1 spektrum receivers (I'm sure other things can contribute).

maybe someone can help me then with determining my BEC amerage needs since I'm still new to electrics and some of my equipment is old and therfore hard to find out what current it's drawing.

Here's my setup....
ESC: Hobbywing 1/8th 150A
Receiver: Old Airtronics MX-3 receiver system (FM) or a Team Durango RTR pull 2.4Ghz system - TDRX1 receiver
Servo - Hitec HS-645MG

Hideeho
Out side of a savox servo with a DSM1 receiver, brown outs are pretty rare. In all honesty, any other (non high voltage) combination should be just fine.

You mentioned a 1/8 ESC. Are you runing this setup in a 1/8 application? If you are, I'm not sure that servo is going to last very long.

Yes - it's in a savage. I've been running it for a few years (granted the truck has been shelved for a few years too). When it breaks I'll get a new one.

So would a 3A BEC be sufficient then? I mean is there any reason to step up to a 10A one?

I just bash in the back yard so if anything I may end up at some point with a HV servo...but probably not...I'd be more likely to just replace it with a high torque servo - perhaps something like SC-1256TG which is still running 6.0V

I run a Savage as well. An XL flux, with some 5mm plates, and jumbo tires, and it weighs over 18lbs.

I bash-only with it as well, but I'm ordering that Polaris BEC. Heck, no 'castle link' required, and it's in a hard-case. It's obviously intended for larger scale applications here, so I can only imagine that it's designed better to handle larger loads. I'm sold, ordered it.

double-post

Hideeho
While it's a big truck, those big tires & actually using a servo saver is whats kept it from selfdestructing. That 1256 you mentioned will make a HUGE difference with those tires. I highly recommend it.

For what your running 3a should be just fine. If you get the 1256 (or something similar) you may find the truck start to glitch. This will be a brown out. I'm not saying it WILL happen, but if it does, 1st try a glitch buster. This is a capacitor used to store extra power when the system isn't using it, & release it when the system damands more than can be supplied. This will probably solve your problem for around $7 from your lhs. If it continues, or you get a high voltage servo, thats when you need an actual BEC like the polaris.

1 word of caution for everyone, if you get the BEC & are running a servo rated at 6.0v DO NOT RUN HIGHER VOLTAGE THAN LISTED. You will kill it, very quickly & it won't be fixed under warranty, no matter how new. Also, verify you receiver can handle 7.4v before hooking it up. I know all spektrum dsm2, & dsmr (the new one does 9.6v) receivers can. I'm pretty possitive newer receivers from other brands (Airtronics fhss-3, 4, & 4t, Futaba fhss/s/t & fasst (some to 8.4v), Radio post does a listed 14.8v:eek:!) can handle high voltage. I don't know about others, so please check before doing it.

Castle BEC - not sure if this is covered in instructions, but make sure to program it before you solder to ESC.

I soldered mine to MMP, and when I pluged it into Castlelink, both the ESC and the BEC powerd on, and the BEC was not recognized. I unsoldered the negative BEC wire, and Castlelink recognized it properly.