A lead acid, or gel cell type battery, when rapidly discharged, it can
sometimes have a temporary recovery effect. I cannot remember the theory of
why this happens. I can only remember something about the internal heat
making the acid more active. There is a complex theory behind this.

If you know the amp hour rating of the battery, and the average amount of
current being pulled from the battery, you can then make an approximate
prediction of how long the battery will last between charges.

If your motor is rated 350 Watts at 12 Volts under load, this means that the
motor will draw about 30 amps. If your battery is rated at 60 amps, then it
should last about 2 hours, considering all conditions being perfect.

When a motor starts under mechanical load, it will draw a very large surge
of current compared to its normal operation. When it has very little
mechanical load on it, will draw less current. Without doing a very in debt
real time analysis of the motor's current consumption, it would be difficult
to accurately predict how long the battery should last.

Testing a battery when not under load, will not give a true indication to
what its real loaded voltage would be. In many cases, a battery will read
nearly the full charged voltage, but when loaded, it will not supply.

When I test gel, or lead acid batteries, I use a dummy load for heavy duty
type batteries. I have a dummy load that will pull 10 amps at 12 volts. To
test the battery, I connect the 10 dummy load across the battery, and then I
monitor the battery on a DVM for at least 5 to 10 minutes. The voltage will
drop a little, and then remain fairly stable if the battery is properly
holding its charge.

As for safety, it is very good that you bought a sealed gel cell. If you use
a liquid lead acid battery in a toy car, and there is a spillage due to
abrupt use, or a roll-over, the acid can be a very serious danger. Acid
spills on skin is a very serious thing! Using a lead acid battery in a
device that is going to have abrupt operation, such as an electric toy car
is not a very good practice.

Never use a liquid lead acid battery in your home, unless there is proper
ventilation. The acid fumes, and the hydrogen gas that can be given off is
very dangerous. The battery will give off most of its fumes during the time
of charging, or discharging.


--

JANA
_____


"rutman" wrote in message
...
Hello.


To being with, please accept my apologies for the noobie questions I
am about to make.

Heres the info.


1. Two small electrical motors rated 12volts 230 watts powers a
Peg-Perego electrical jeep. it looks like one of them power wheels
ride on toys. Since the original battery died, I started asking
questions and reading previous usenet posts as to replacing the
expensive power wheels battery for an ordinary car battery.

I received quite a few replies. Some were cons others pros regarding
the car battery adaptation idea. Apparently this has been done
sucessfully before my many people. Some replies were concern as to the
safety etc. Following advice from this group as well as having read
meny hours of googles , I decided to install a new heavy duty deep
cycle GEL battery. It cost me almost triple as much as buying a
regular 12vs car battery. However, from my own personal research as
other people advices as well, it looks like this was the way to go.

I also bought an inline 40a fuse and installed it on the positive
cable.

My kid took out the jeep for a ride, and he was having a blast,
until..... the jeep started slowing down. WAYYY down.. almost to a
crawl. This is odd, i told myself.. it surely did not seem like the
so called deep cycle battery lasted any longer that the orginal small
power wheel jeep battery! we are talking like 40 minutes of play time
with my kid going around for a ride or two.

So I popped the hood. Checked all the cables. The positive and
negative cable were warm but not Hot.. good sign I guess. I touched
the battery just to get a touchy feeling.. cold.. I went under the
vehicle and touched both motors. I was thinking that maybe the motors
were over heating or something as that, which might caused the jeep to
crawl. They were warm , not hot at all.

Took out my volt meter. Checked the battery for power.

It was reading at 11.40 volts!. thats almost a full charge.!

now heres the really odd part.

left the jeep sitting there for about 40 minutes while i went to a
local canadian tire to purchase a battery charger ( I didnt have one,
and since I just bought this deep cycle.. arghh.. more money )
came back. I was unpacking the goodies and noticed that my son had
already jumped back onto the truck and he was doing some wheelies! all
of sudden the power came back for about 5 minutes before dropping to a
crawl again. Check the battery's voltage. It was reading at 11.20
volts. Had my son drive the jeep until it wouldnt move anymore to see
how fast the deep cycle battery drained.. when the jeep coulnt move
anymore and I connected the volt meter, it read at 10.20 volts.


now here are my questions.


If the battery is reading at 11.40 volts ( almost a full charge ) why
are the motors turning sooo slow.

I know that the motors are rated at 12v 230 watts.. so if the battery
drops below 11 volts should this caused the motors to simply quit
turning the wheel?


I didnt check for the battery Ah rating. I took it for granted that a
deep cycle battery meant for a small boat, rideon lawn mover , or even
a small vehicle should be enough to put out enough juice to run two
12v motors rated at 230watts... but maybe i am wrong?

the original batteries the jeep uses are 12v 10Ah....

Could it be that the deep cycle battery may be defective? could this
explain the drop of power being supplied to the motors?


Finally.


whats the best setting to charge the deep cycle battery? My charger
has a setting for 10a and 2a. I am currently using 2a setting. (
trickle charge )