Help me in choosing toy car battery

Thread Starter

sachin1101

Joined Jan 4, 2014
1
Hi,

I need to replace Sealed Lead acid battery(SLA).
SLA specification - 6v X 700mAh


If I use my understanding then Total power of the battery
= 6 x 0.7 = 4.2 (I forget the power unit )

I am thinking of using commonly available NiMH 1.2v AA batteries.

however these AA batteries has high mAh ( 1900 to 2500) when compared.

So my basic question is can 4 AA batteries of 1.2v 1900 mAh can be used in place of the original battery (SLA) ?

Please confirm my understanding -
The current drawn from the battery depends upon the resistance of the circuit. The NiMH battery combination ( 4.8 x 1900 mAh) wont burn the RC toy car circuit as it would draw ~700 mAh.

:) Please help.
thanks
Sachin
 

MikeML

Joined Oct 2, 2009
5,444
mAh is the size of the fuel tank, not the pressure at its outlet, nor the pipe coming out of it.

Your new battery must have nearly the same resting voltage as the old one. (6V=the pressure at the fuel tank outlet).

If your 700mAh battery lasted 2 hours, then a 1400mAh battery will last twice as long (the size of the fuel tank).
 

wayneh

Joined Sep 9, 2010
18,164
If I use my understanding then Total power of the battery
= 6 x 0.7 = 4.2 (I forget the power unit )
That would be watt•hours. The electricity entering your home is usually metered in kW•hr. For whatever reason, we usually stick with mA•hr or A•hr with batteries. As noted, it's a capacity rating. More capacity equals more run time (as long as the current
required can be maintained).

I think the 4 AAs will work nicely. There's no reason not to try. In my opinion there would be little risk of using 5 AAs, but there may be no need.
 

bountyhunter

Joined Sep 7, 2009
2,512
Hi,

I need to replace Sealed Lead acid battery(SLA).
SLA specification - 6v X 700mAh


If I use my understanding then Total power of the battery
= 6 x 0.7 = 4.2 (I forget the power unit )

I am thinking of using commonly available NiMH 1.2v AA batteries.

however these AA batteries has high mAh ( 1900 to 2500) when compared.

So my basic question is can 4 AA batteries of 1.2v 1900 mAh can be used in place of the original battery (SLA) ?
YES, but you need five cells since the nominal cell voltage is 1.25V.
 

GopherT

Joined Nov 23, 2012
8,009
One other thing to watch out for is the C-rating of the batteries. That is, how much resistance is in the battery (internal resistance) and, therefore, what load (amps) can be drawn from the batteries power and still be at 12 volts (near 12 volts).

The higher the C rating for RC cars - especially with brushless motors - the better.
 

bountyhunter

Joined Sep 7, 2009
2,512
Hi,

I need to replace Sealed Lead acid battery(SLA).
SLA specification - 6v X 700mAh


If I use my understanding then Total power of the battery
= 6 x 0.7 = 4.2 (I forget the power unit )

I am thinking of using commonly available NiMH 1.2v AA batteries.

however these AA batteries has high mAh ( 1900 to 2500) when compared.

So my basic question is can 4 AA batteries of 1.2v 1900 mAh can be used in place of the original battery (SLA) ?

Please confirm my understanding -
The current drawn from the battery depends upon the resistance of the circuit. The NiMH battery combination ( 4.8 x 1900 mAh) wont burn the RC toy car circuit as it would draw ~700 mAh.

:) Please help.
thanks
Sachin
By an interesting coincidence, the mA-hr rating for a AAA size Ni-MH cell is also 700 mA-hr. That means you could use five AAA cells and have just about exactly what you have now except it would probably be smaller and lighter.

http://www.all-battery.com/aaa700ma...22_a_7c10407&gclid=COHW48v75bsCFcJqfgodD24AAA
 
Top