New battery tech for battery replacement (2 9volts)?

[Chrishew09]

could this be repacked?

http://cgi.ebay.com/RC-CAR-BATTERY-P...QQcmdZViewItem

I dont think so, it looks like its just 8 1000mAh 1.2V cells in series.

[athomas]

Here is a 9 volt I was looking to purchase. http://www.thomasdistributing.com/ip...le-battery.php

They show a 2.5A max pulse output. They might work, but I would get the actual specs on the solenoid first. If it is indeed a 3.9A draw then they won't. I hope it does work out. This would bbe a great find.

[Chrishew09]

I cant believe that the solenoid draws over 3A continously, maybe pulsed.

[UThomas]

Would the 2 NiHm 9volts together work with the stock charger?

T

[athomas]

I cant believe that the solenoid draws over 3A continously, maybe pulsed.

When on, the solenoid draws 3.9A based on rough calculation. I don't know the real value but it is very high but probably not as high as 3.9A. There are specs here on AO somehwere that state the real value based on the solenoid data sheet.

[Chrishew09]

When on, the solenoid draws 3.9A based on rough calculation. I don't know the real value but it is very high but probably not as high as 3.9A. There are specs here on AO somehwere that state the real value based on the solenoid data sheet.

Yea I saw them once to but I cant find it, all I need is the part number, at one point in time I got a link to the manufactures website that has all the specs.
You know, you can get these exact same solenoids at different voltages, but I think you sacrifice pulling strength (i think).

[athomas]

Yea I saw them once to but I cant find it, all I need is the part number, at one point in time I got a link to the manufactures website that has all the specs.
You know, you can get these exact same solenoids at different voltages, but I think you sacrifice pulling strength (i think).

You don't sacrifice pull strength at all with the different voltages as long as you keep the power rating the same. A lower voltage solenoid would draw more amps. A higher voltage solenoid would draw less amps. As long as the power consumption was the same, the pull strength would be the same.

The emag 18v solenoid was used to keep the current draw down to the value it uses. If a lower voltage one was used, the current requirement would be even more.

[Chrishew09]

You don't sacrifice pull strength at all with the different voltages as long as you keep the power rating the same. A lower voltage solenoid would draw more amps. A higher voltage solenoid would draw less amps. As long as the power consumption was the same, the pull strength would be the same.

The emag 18v solenoid was used to keep the current draw down to the value it uses. If a lower voltage one was used, the current requirement would be even more.

I need to investigate this, I wonder what kind of MOSFET or transistor is used for the solenoid, I imagine when it was designed there wasn't the options there are today for high current MOSFET's, it could be possible to replace the solenoid with a 9v one, and change the MOSFET to a higher current one. Then the size of the battery pack could be cut in half...hum....

[athomas]

The board isn't the problem. The components can handle a lot more current. The batteries were the problem. When the emag was developed, it was cost prohibitive to put on a battery pack with a higher current capacity and lower voltage. To lower the voltage to 9v and maintain the same shot capability as the current design, you would need a 1300mA battery pack. I think you can get this in a lithium design, but I think even today it is still a long shot for a AAA NiMh battery design. Maybe you can find it in a 2/3AA design, but you wouldn't enjoy a big space saving once you go to the larger diameter AA type cell. The C rating may be higher though. Another problem you will run into with NiMh cells running at twice the current, is overheating. They are now running at a high C rate of discharge using the 16.8v designed circuit. If you double the current draw, it may exceed the capability of the cells to supply the current and will lead to reduced charge life and premature cell failure.

[Chrishew09]

The board isn't the problem. The components can handle a lot more current. The batteries were the problem. When the emag was developed, it was cost prohibitive to put on a battery pack with a higher current capacity and lower voltage. To lower the voltage to 9v and maintain the same shot capability as the current design, you would need a 1300mA battery pack. I think you can get this in a lithium design, but I think even today it is still a long shot for a AAA NiMh battery design. Maybe you can find it in a 2/3AA design, but you wouldn't enjoy a big space saving once you go to the larger diameter AA type cell. The C rating may be higher though. Another problem you will run into with NiMh cells running at twice the current, is overheating. They are now running at a high C rate of discharge using the 16.8v designed circuit. If you double the current draw, it may exceed the capability of the cells to supply the current and will lead to reduced charge life and premature cell failure.

Like you mentioned before, I think the answer is a Lithium based cell, and you are right when they designed the emag Lithium cells where not easily avalible.
There are some inexpensive LiPoly cells out there for the R/C market that have a very high "C" rate that are rated for 11.1V that would work.

[UThomas]

Got my 1000 mAh battery pack in yesterday and installed it - works like a champ and looks great. It only cost $41 shipped. Will post picks later this week.

[UThomas]

Paid $42 through paypal and had it less than a week later. I highly recommend Onlybatterypacks; I worked with:

Regards, Jeffrey
Onlybatterypacks.com
Ph: 262-246-0455
Hours: 9am-5pm CST

In my original inquiry I specified:

*Rechargeable
*16.8 volt
*14 NiHm AAA's laid out in a 4x2 rectangle with a 3x2 rectangle on top (so about 5 inches long, 2 inches wide, 1 inch tall - like a trapezoid when looking at the tops)
*Looking for 1000+ mAh
*Termination with wires (I'll solder it to the original connector)

Very easy all around.

[Russ]

UThomas,

that's sweet!

[DoritoBandito77]

Anybody know if the extra 350mAh would be enough to power Mag + warp + haloB?

i am already running my warp this way and it rocks:

http://www.automags.org/forums/showthread.php?t=210132

I have been wanting to drop my halo batteries for a while. i have found some old post of people doing this before but they didn't elaborate and said it was "problematic".

if anybody has done it let me know

i think i would just need a 9v regulator like i used in my warp but in the halo, then simply route the power to it.

thoughts?

[Chrishew09]

Anybody know if the extra 350mAh would be enough to power Mag + warp + haloB?

i am already running my warp this way and it rocks:

http://www.automags.org/forums/showthread.php?t=210132

I have been wanting to drop my halo batteries for a while. i have found some old post of people doing this before but they didn't elaborate and said it was "problematic".

if anybody has done it let me know

i think i would just need a 9v regulator like i used in my warp but in the halo, then simply route the power to it.

thoughts?

Here is my suggestion, run the 9V reg off the 12V reg this way the 9V reg will not be as hot b/c less voltage will need to be dropped at the 9V reg. But make sure that the 12V reg you have can handle the currents of both the warp and halo. Another suggestion is to find out if the Halo will run up to 12V, I wouldn't be surprised if it did, it might even have its own voltage regulator in it that knocks the voltage down to 5V or something, just a thought.