Battery/Servo combo
 

We have a question on how much amp draw we can get out of lipo or NIMH Batteries.

We are putting it on a Mojo Moass60.

We were thinking of these servos. Anyone know about them?
http://www.hobbycity.com/hobbycity/s...sp?idProduct=2



This UBEC, But what size lipo? 3s 800mah weighs about the same as a AA pack, but is that big enough?
http://www.hobbycity.com/hobbycity/s...idProduct=6320

We can also use a 6v AA NIMH 2600ma pack too. Would that be too many amps out of these though?

RE: Battery/Servo combo
 

Remember that the battery connection to the rcvr will only pass 3 to 4 amps continous and at 4 probably not for long. On a Mojo, at a relatively slow 3D pace, servo draw will (should) not be a problem. Your peak current draw may be high but only for parts of a second. Just be sure not to stall any of the servos. To be sure you can check with an in-line current meter. It is really the only way to know for sure. Good luck.

RE: Battery/Servo combo
 

Those wouldn't be my first choice for servos and as for batteries then A123 cells are your very best option. They'll provide ten times as much current as you'll ever need and you can choose from 1100mAH (very light) or 2300mAH (100A current capacity). A123s don't need regulators either so you get a much simpler installation.

RE: Battery/Servo combo
 

xjet, what would be your choice then? Any good vendors for A123 batteries?

RE: Battery/Servo combo
 

Well if you've got the money you can't go past the Hitec coreless digitals such as the [link=http://servocity.com/html/hs-7965mg_servo.html]HS7965[/link] but if you're on a budget then things get a bit trickier.

I'm hesitant to recommend any of the servos sold by Hobby City mainly because they keep changing the specs without telling anyone. Quite a few people have already been caught out by finding an HC servo they're happy with then ordering some more, only to find out that the new ones are grossly inferior to the originals.

I've got HS5925 servos on my Mojo 60 and they're wicked-fast and powerful with an A123 pack but I'm also the first to confess that this really is overkill for a lightweight profile bird.

A more cost-effective option might be the [link=http://servocity.com/html/hs-5625mg_digital_speed.html]Hitec HS5925[/link] but by today's standards, they're still pretty pricey for a 3-pole digital servo.

In my tests, the Savox servos proved to be *very* good but I don't know of a US reseller of these yet. Their equivalent to the HS5625 has a RRP of $42 and their equivalent of the HS7965 is $65.

The bottom line is that you can use almost any metal-geared servo in the tail of a Mojo 60 and any you can even get away with nylon-geared servos on ailerons. I've got Futaba 3010s on the wing of my Mojo but they're an *awful* servo very, very sloppy, so I couldn't recommend them.

As for A123 packs you can get them from a variety of sources but I've found [link=http://www.radicalrc.com]Radical RC[/link] to offer good prices and unbeatable service.

RE: Battery/Servo combo
 

In their infinte wisdom (and arrogance) the RCU moderators seem to have disabled my ability to edit my own posts so I have to post this correction I meant the HS5625, not 5925 above.

Sigh!

RE: Battery/Servo combo
 

Thanks for your input. Anyone else have suggestions?

RE: Battery/Servo combo
 

You're kidding about this, right? Why would they single you out like that? And clearly, not being able to edit a post does nothing to stifle your ability to simply make another post, so what could they possibly be trying to prove?

RE: Battery/Servo combo
 

Not kidding it was done once before. I expect it's "punishment" for speaking my mind about shonky products (not good for advertising revenue perhaps).

I've also had my ability to include a .sig and an avatar deactivated.

Small minds as they say...

RE: Battery/Servo combo
 

Wow. That's sad. [:o]

RE: Battery/Servo combo
 

On one of my Mojo 60's, my MoAss in particular, I am using an Intellect 6V 1500mah pack from Radical RC that is driving Hitec HS 5625MG's and DS821's and it is a great combo!!!!! Very light and plenty of power/flight time. At some point, I would like to try out the A123's myself.

RE: Battery/Servo combo
 

Tom at Wild Hare has a nice A123 starter package:

A123 battery starter kit

We now have a nice kit to get you started with the A123 battery technology. The kit includes 1 2500mah battery pack (sufficient to properly power any R/C aircraft, really), a Cellpro 4S charger, charge cord to connect to the battery pack or any charge jack, and one Smart Fly super switch

GO TO: http://www.wildharerc.com/html/specials.html

Walt...

RE: Battery/Servo combo
 

Be careful they may not be genuine A123s to the best of my knowledge (although I may be wrong), A123s only come in 1100 and 2300mAH capacities. It's either *not* a true A123 or they're overstating the capacity. Either way, this does not appear to be particularly ethical.

Check [link=http://www.a123systems.com/products]the A123 Systems website[/link] for more info.

RE: Battery/Servo combo