Batteries

[stinger]

Looking to get more info on batteries. Everyone I speak with, complains of the duration (run time) hey get out of their batteries. I'm told to get 4200's or maybe even 4800's and this will help somewhat.

I was just chatting with a R/C car guy and he says he can get me the following. Your thoughts please:

4000mah Capacity
7.4 Volts
44mm X 137mm X 14mm
20C Constant(80 amps)
30C Sustained(120 amps)
50C Burst(200 amps)
185 grams
Comes with Apache/Hyperion Taps


6000mah Capacity
7.4 Volts
44mm X 137mm X 22mm
20C Constant(120 amps)
30C Sustained(180 amps)
50C Burst(300 amps)
297 grams
Comes with Apache/Hyperion Taps


8000mah Capacity
7.4 Volts
44mm X 137mm X 26mm
20C Constant(160 amps)
30C Sustained(240 amps)
50C Burst(400 amps)
365 grams
Comes with Apache/Hyperion Taps


9000mah Capacity
7.4 Volts
44mm X 137mm X 32mm
20C Constant(180 amps)
30C Sustained(270 amps)
50C Burst(450 amps)
443 grams
Comes with Apache/Hyperion Taps

12000mah Capacity
7.4 Volts
44mm X 137mm X 38mm
20C Constant(240 amps)
30C Sustained(360 amps)
50C Burst(600 amps)
545 grams
Comes with Apache/Hyperion Taps


So these batteries appear to be triple the capacity that I have been told. Will these work ?

My system is currently 7.2 V but he says these will still work.


Thoughts?

U-235

[JWLaRue]

All depends on your power

All depends on your power needs....

For example, I run a 4 amp-hr, 12 volt NiMH battery pack with my 1/9th scale Seehund. Operating the boat at mostly scale speeds (with an occasional move like heck to get out of someone's way), that provides me something on the order of 2-1/2 to 3 hours of run time. This includes running the Engle piston used for the ballast system.

-Jeff

[stinger]

longer life

Would not this 12000 mah battery last much longer than a 4200...seems logical, but I dont' know mcuh about batteries. So if the 4200 lasted an hour, would't the 12000 last at least twice as long. I'm just not intetrested in changing batteries and if I can minimize this, then that's the way I want to go...

current set up is 7.2 V 4200 mAH

Thanx!

[chuck chesney]

A pretty good rule of

A pretty good rule of thumb is that bigger is better. Nothing better than having the peace of mind of knowing that your boat and transmitter are not going to run out of juice. If the higher capacity battery will fit in your boat, then thats a good way to go.
By the way, what is the name and source for thr high capacity batteries that your friend gets?

[stinger]

batteries

Bigger is better (in this case) yes, I can agree with that. I believe the physical dimensions will work too. So, I'll get hooked up with the 12000's.

As far as a name brand, he didn't say. I suppose I could easily ask and get back with you if you like. If anyone else is interested in these batteries, e-mail me, I don't mind giving out the info. He said he is a factory sponsored race car guy and can get good deals.

Thanks for all of your help...

U-235

[Guest]

batteries self discharge over a

batteries self discharge over a period of time.

12 AH sounds like overkill to me, after an hour or two I've usually had enough of sailing around and want to bring it in anyway.

Andy

[stinger]

overkill

Over-kill yes, but hey, I'm the king of overkill. I keep hearing how after 30 mins, the sub must be brought in to recharge batteries. If I thought I could get between an hour or two like you mention, I wouldn't be so interested in the 12's.

I guess the problem is no personal experience with batteries leaving me to get "bigger is better". I hate to have to buy a set that lasts 30-40 mins on to have to buy another set.

Just my thoughts... if anyone can shed any light on running time vs battery size that would help.

1/40 scale VII Robbie - twin 400's motors.

thanx!

U-235

[Guest]

4 or 5Ah will be

4 or 5Ah will be ample.

Speed 400's won't draw more than an Amp or so provided they are geared appropriately for the props.

With the money you have saved, purchase a leveller, this will increase your enjoyment of the piloting the boat enormously.

Andy

[bob_eissler]

A 3800 mha 7.2 v

A 3800 mha 7.2 v lasts me at least 45 min in my Robbe type 7 & I think is about $24.00 at Radio Shack. I suspect the batteries you are specing are a lot more expensive. Also, it takes about 10 or 12 min. to recharge a Nickel metal battery pack with a modern charger.

[stinger]

great advise

Great, that's the info I was looking for... cost savings, yes, there definately will be cost savings if I don't have to spend that kind of $$$. Thanks everyone for all of your help, I think I now know what to do... 12's ... no just kidding...

Think the 4200's or 4800's will be just fine....


Thanx!

U-235