When is it necessary to run with receiver batteries?

[YSL]

guys..

im running the RF with 7.4V Lipo, 4000mAh.
1. JR RS10DS receiver (supports up to 10Ch)
2. Airtronics/Sanwa ERG-VB Servo (13kg torque)
3. 9CH JR Transmitter
4. Cheapo brushless with ESC, 1200kV

it seems the rig is operational even without the NiCd 4.8V receiver pack.
im surprise! i will be putting up a rear dig for the Kyosho RF possibly within the next couple of hrs, therefore will add in another rear servo.
at the moment, there's no BEC as well.

my question is, when do you guys think it's necessary to put on the 4.8V receiver pack?

cheers

[clockworks]

Originally Posted by YSL

guys..

im running the RF with 7.4V Lipo, 4000mAh.
1. JR RS10DS receiver (supports up to 10Ch)
2. Airtronics/Sanwa ERG-VB Servo (13kg torque)
3. 9CH JR Transmitter
4. Cheapo brushless with ESC, 1200kV

it seems the rig is operational even without the NiCd 4.8V receiver pack.
im surprise! i will be putting up a rear dig for the Kyosho RF possibly within the next couple of hrs, therefore will add in another rear servo.
at the moment, there's no BEC as well.

my question is, when do you guys think it's necessary to put on the 4.8V receiver pack?

cheers

Receiver packs aren't necessary with electric RC. As you've discovered, the ESC provides the power needed for the receiver and servos through it's built-in BEC.

As you add more or higher-powered servos, you need to use an external BEC, as most ESCs can only supply a couple of amps.
You could use a receiver pack instead of an external BEC, but a BEC weighs less and you only have to worry about charging the main pack.

[Grizzly4x4]

Originally Posted by clockworks

Receiver packs aren't necessary with electric RC. As you've discovered, the ESC provides the power needed for the receiver and servos through it's built-in BEC.

As you add more or higher-powered servos, you need to use an external BEC, as most ESCs can only supply a couple of amps.
You could use a receiver pack instead of an external BEC, but a BEC weighs less and you only have to worry about charging the main pack.

x2

I think you will find that once you go to two servo's you will want a BEC. The rig may be drivable without one but when you get the steering in a bind I bet you will notice the ESC shutting down. I always run a BEC in a crawler, even if I only have one servo. It just makes your system more reliable.

[YSL]

Originally Posted by Grizzly4x4

x2

I think you will find that once you go to two servo's you will want a BEC. The rig may be drivable without one but when you get the steering in a bind I bet you will notice the ESC shutting down. I always run a BEC in a crawler, even if I only have one servo. It just makes your system more reliable.

Thanks!

great advice.
problem is, i can't seemed to be able to find any RC shops selling BEC here in Tokyo.
shipping cost from the US will be costly if i just need a BEC..

hmm..

[YSL]

Originally Posted by clockworks

Receiver packs aren't necessary with electric RC. As you've discovered, the ESC provides the power needed for the receiver and servos through it's built-in BEC.

As you add more or higher-powered servos, you need to use an external BEC, as most ESCs can only supply a couple of amps.
You could use a receiver pack instead of an external BEC, but a BEC weighs less and you only have to worry about charging the main pack.

clockworks.
thanks a bunch for sharing the knowledge. i've always read about BEC etc..but dun quite understand the real purpose since all along i've been running with receiver packs (including my Tamiya TXT, with dual servo) until you wrote this.

good stuff.
highly appreciated!

cheers

[clockworks]

Originally Posted by YSL

Thanks!

great advice.
problem is, i can't seemed to be able to find any RC shops selling BEC here in Tokyo.
shipping cost from the US will be costly if i just need a BEC..

hmm..

Same problem here in the UK - no shops actually selling BECs. Everyone recommends the Castle BEC, but there aren't any available in the UK as they are currently changing to a new distributor.
I guess the UK crawler market is too small. There are some low current BECs available, suitable for RC aircraft, but no good for the high servo loads of a crawler.

I've noticed a few Hong Kong eBay sellers advertising 5A BECs cheap. Maybe you could try one of those?

[NSR ACCORD]

yea the hong kong dealer are pretty good. Look up http://www.hobbyking.com/hobbycity/s...idProduct=3735 they have all kinds of goodies. hope this help.

[YSL]

Originally Posted by clockworks

Same problem here in the UK - no shops actually selling BECs. Everyone recommends the Castle BEC, but there aren't any available in the UK as they are currently changing to a new distributor.
I guess the UK crawler market is too small. There are some low current BECs available, suitable for RC aircraft, but no good for the high servo loads of a crawler.

I've noticed a few Hong Kong eBay sellers advertising 5A BECs cheap. Maybe you could try one of those?

thanks again.
btw..do you know of the difference between eBay 5A BECs versus Castle's BEC?
i bought Lipo battery, ESC and charger online from Hong Kong, the shop do carry 5A BEC as well..should we stick to Castle's for reliability?

cheers

[NSR ACCORD]

the castle creation bec you can adjust the output voltage, not sure about the other one.

[clockworks]

The Hong Kong ones that I saw had a jumper to swap between 4.8v and 6v.
The Castle BEC has more voltage options, but you need to buy the "Castle Link" programming kit to change it. This costs as much as the BEC.

I've no idea if the Castle BEC is any better - it's possible that they are all made in the same factory in China.
American customers undoubtedly get good customer service from Castle if things go wrong. In other countries, service for Castle equipment will depend on the importer/distributor. If you import a Castle BEC into Japan, you'll have to send it back to the retailer, which will probably cost as much as buying a new one.

If I need a BEC - not sure that I will, as my Novak ESC has a built-in 5A BEC - I'll probably try a Hong Kong one.