Mad Wax

Anyone use one of these? Looks useful if the main pack packs it'll go back to secondary pack (a AAA 4.8V should do)

http://www.rc-car-online.de/failsafe_eng.htm#3

chevyman_de

I don't think a 4-cell AAA pack is a good idea. AAA cells are not exactly up to the loads of the high power servos in a largescale car. If you have only four cells that could easily cause a low-batt failsafe to engage. I'd definitely opt for a 5-cell backup pack.

chowderhead72

My Feedback: (4)

I agree with Chevyman although if you were to use a nitro type reciever pack (1200-1500mah) you might have something btw AAA's are only 700mah and not much better than nothing.

Mad Wax

Only for emergency failsafe though, surely it's enough?

chevyman_de

Even when it's an emergency, they're are still the same servos under the same loads. Some digital servos need 6 volts to run properly.

Mad Wax

What about when using analogue servos? (Hitec 645)

badz

My Feedback: (1)

One 1/4 scale servo will drain them 4aaa's in no time flat...toss a 5cell hump pack in it from a nitro or just run dual sub c packs....added weight wont mean much unless your racing....

chevyman_de

Four cells should be OK, but I would stay away from those tiny AAA cells and use AA cells instead.

Transporter67

Why not just use a normal signal and voltage failsafe and have a spare battery pack?

In case of total failure of the battery pack I have a 6v relay connected to the kill switch that shuts the engine down if the battery pack fails or becomes disconected.