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Thread: Lithium Ion battery for the E/X-Mag?

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  1. #1

    Lithium Ion battery for the E/X-Mag?

    There's no doubt that battery technology has advanced from the time the E-Mag was initially introduced and I was wondering if there has been anybody that has looked into developing a Lithium Ion battery pack for the E-Mag.

    You probably need to develop a new charger as well, but I think the increased shot count per charge and weight savings VS the stock NiMH might make this an appealing upgrade for E/X-Mag owners.

    Thoughts AO?
    Steve Shuey , Team Crimson Reign

  2. #2
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    There is probably a battery pack ready made for the RC Airplane and heli market that would be readily adaptable to the emag.

    Plenty of charger options too. Would just take some research to find one that fits and at the right voltage. I believe the lithium cells come in at 3.7 Volts nominal. So you could expect to get packs in multiples of that voltage.

  3. #3
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    The lithium polymer cells are commonly used by the electric rc airplane and helis. These are popular because they lack the heavy protective casing around the cells. Since the E-Mag has a metal battery "case" anyway I see no reason that these batteries couldn't be used safely for this application.

    If you go messing around with lithium batteries make sure you take some time to learn about their quirks and how to safely use them.

    For instance, they like to catch fire if seriously abused. Also if they are over discharged there is a risk that they can catch fire when recharged. Or if they are charged with the wrong type of charger.

  4. #4
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    Someone get me some specs. I just happen to work for a conpany that makes lith car batteries. Ill talk to the engineer

    To leave feedback: Click seller/buyers name, Click feedback score, Click leave feedback

  5. #5
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    its hard to get the size right. 4 cell lipo is your go too.
    3 cell would work i think at 11.1 v.
    4 cell is 14.8 v
    but with lip you need a cutoff installed so you dont balloon your packs and have it melt your gun when it goes bye bye.

    ive been looking into getting packs that will fit but its really hard to get the size down.

    the the MaH would be small. but that wont be an issue since the lipos would run you for days.

    could get ahold or Orion, Maxxamps, Venom, etc, but they are big guys in the industry and an order would have to be for a 1000+ i think, if they could make 100+ for good price i may be able to buy em and resell to you guys.

    issues:-
    -size
    -price
    -cutoff for to save the battery.
    -and hookup to the marker.
    ** question for the techs who know:
    *_* can you opperate the emag off of 11.1 v? if so i will run testing.
    My sydarm weighs less than yours!!!

  6. #6
    Join Date
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    Here is a copy of a battery pack explanation I did a while back.

    A 4 cell pack would have a 14.8V nominal rating. 14.8V would cause a reduction in power by about 22%. That should still trip the sear, but it would cut into any buffer needed to maintain operational consistency in all instances. That means you better keep the mechanism clean. It would probably be better to add an extra cell.

    Don't go exactly by the rating on the cells or packs. In reality, Lipo cells have a fully charged voltage value of 4.25V so most charger limit it to 4.2V. The minimum safe voltage is 3V so most use a cutoff of 3.3V. That gives a four cell pack a voltage range of 13.2V to 16.8V. The discharge line from 16.8V to 13.2V is fairly linear and results in the 14.8V nominal rating. The calculations show a 15V average but in reality its not perfectly linear so the real average is 14.8V.

    NiMh cells have a fully charged voltage value of about 1.4V but it drops to 1.3V very quickly so the 1.3V value is used for the upper value when determining average operating outputs. The minimum voltage is 1.0V, but the drop from 1.1V to 1.0V occurs very quickly so the 1.1V value is used for the lower voltage. The resulting average is 1.2V which is the industry value used for packaging. A 14 cell pack rated at 16.8v actually ranges from 18.2V to 15.4V.

    Checking the voltage values of the lowest value for each pack type, it shows a reduction in power by 27% for the LiPo compared to the NiMh pack. This is worst than the 22% calculated using nominal values. As the pack gets discharged, you might end up with firing issues using a 14.8V LiPo pack.

    Therefore, I would recommend the 5 cell LiPo. The overall voltage will be a bit higher using the 5 cell LiPo pack. This will cause higher current draw which will heat the solenoid more. Its a 20% increase in power consumption when the battery is fully charged. I don't think the dwell of the solenoid will allow it to catastrophically overheat. If it proves to be a problem, put a 5Watt 0.5ohm resistor in series with the battery pack. That will bring the pack down to the same operating parameters as a NiMh pack.

    LiPo packs and lithium chargers in general are easily configured to be safely charged these days. An off the shelf RC charger has the ability to properly balance a lithium based battery pack and the packs have charge/discharge regulators built in so that you can't charge or discharge them past their danger point.
    Except for the Automag in front, its usually the man behind the equipment that counts.

  7. #7
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    Quote Originally Posted by knownothingmags View Post
    *_* can you opperate the emag off of 11.1 v? if so i will run testing.
    If a 3 cell is all that could be fit into the Emag battery pack a voltage "boost" circuit could be added provided there is a little room left over.

    There is always another way to skin the cat... it just depends on how much work one wants to do.

    I just did a google search for lipo cells and came up with a few promising links but don't have the time to investigate in depth right now.

    Could someone post the internal dimensions of the Emag battery?

  8. #8
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    I got the packs in today. Again this is where it stalls for me until I get my new circuit board. That said here's option one for me.









    I'll eventually charge these and do a few test cycles...check that they can handle high rof without catching fire...if we're good I'll try to source individual cells for a single pack. If that falls through I may look at buying more of these and dissecting until I can scavenge enough cells for a proper balanced pack.
    faster is better...

  9. #9
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    Quote Originally Posted by 2xFast View Post
    I got the packs in today. Again this is where it stalls for me until I get my new circuit board. ...

    ...I'll eventually charge these and do a few test cycles...check that they can handle high rof without catching fire...if we're good I'll try to source individual cells for a single pack. If that falls through I may look at buying more of these and dissecting until I can scavenge enough cells for a proper balanced pack.
    These will handle the load quite well. Their specs indicate that they can handle 17.5A which is much more than the required 6A. The voltage for a 5S pack (3S + 2S) is more than adequate and will produce the required 6A.

    To run them just connect in series. For charging, you'll have to connect each pack to a charger independently for proper balance charging, or make an adapter to convert both plugs to interface a single plug so that both packs can be balance charged together.

    The packs are too long for the emag case. Make a piece that bolts onto the bottom of the emag pack to extend its length, and you can still use it.

  10. #10
    I am playing around with this light battery idea too. I will leave the battery packs to someone else with the know how but i was thinking about 5 axis machining a new battery housing for the new pack.....make it look cool.
    If done right it could give the gun a new look.

  11. #11
    Oops didn't notice you were shooting for 5s. Voltage should be plenty. Good luck with that.
    "Accuracy by aiming."


    Definitely not on the A-Team.

  12. #12
    Join Date
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    Time to refresh this thread. I'm in the market for a new battery for some lowers I just bought. I always disliked how big the battery is on Emag lowers. So has anyone made any progress on a new battery option? I'm not an engineer, but I work with a few. My co-workers had a few ideas, but nothing that hasn't already been said.

    So now my question is could we just get a company to custom make a new battery pack for us Emag owners? I found these 2 websites that might be helpful:

    http://www.batterygiant.com/custom_p...lder/start.asp

    http://www.houseofbatteries.com/cust...FeJF7AodLQYAuw

    If we just gave either of these companies the specs of what we need couldn't they just make a new battery?

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