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View Full Version : Custom battery packs built, tech questions answered.



cmattp
05-10-2003, 09:13 AM
Hello all. I am a new member to this forum, and look forward to skimishing with all of you soon. I work at Batteries Plus in Round Rock as a tech, and have been custom building battery packs for about 7 years. If anyone has any questions regarding batteries, or charging characteristics, feel free to ask me. And, I can custom build anything you want, with any battery you want me to get you.

Katana
05-10-2003, 02:54 PM
Hello cmattp, great to hear it. Up to this point, I've purchased specialty packs from the airsoft retailers because they're purpose-built and go in with no problems. You end up paying a bit extra this way, however.

I've assembled a few of my own packs as well, but prefer to avoid doing so as soldering tabs onto cans is such a hassle for me. It seems that regardless of how I prep the surface the little buggars refuse to want to stick right. As a result, whenever it's not an emergency, I prefer to have someone else do the 'suck' part of the work for me.

I don't know if you've played elsewhere before or not, but assuming you've surfed the retailer web-sites and have seen the prices they sell pre-built packs for, you'll see what we've been paying. If you can reliably beat that price and/or deliver faster, then you'll have my business.

Hope to see you on the field soon!

cmattp
05-10-2003, 03:51 PM
Hello, Katana. Actually I have a resistance welder at work. (Batteries Plus) I'm the tech at the Round Rock Store. So I do no soldering directly to the can of any cells. If there is a game on May 18 I wilol be there. With Mothers Day, that puts a damper on playing. Look forward to meeting you.

Agrovale
05-12-2003, 09:18 PM
That's cool, you posted before we called you. I don't remember who gave me your number about airsoft packs, but I wanted to see what you would charge for a NiMh AUG pack and a 9.6V 3000mAh pack? :)

cmattp
05-17-2003, 10:10 AM
Hey Agro, I attempted to fit 8 3000 mah subc cells in my Aug, and there is no way to make subc's work in this case. but there is a 4/5a cell nimh (sanyo) @ 2150 mah. that will work in this case. I can assemble that pack for you for $29.00. The problem with nimh cells is that you get lower shots per second as the battery discharges, versus nicd that withstands the voltage drop better, so you get more consistancy on shots per second.

AustinWolv
05-17-2003, 12:07 PM
cmatt, excellent point that I've experienced in both R/C car racing and in Airsoft. I have only one 3000 NiMH pack (9.6V), and I'm in no hurry to buy another over NiCd's because of that reason. Being in the middle of a firefight, and having the NiMH voltage drop off isn't all that fun. Then waiting for the voltage to stabilize some and then be usable again is just plain wacky IMO.

That was a major complaint about the NiMH's back when I raced stock class (when the 3000's were first coming out). Only modified class racers wanted to use them because of the long runtime of them, but stock guys wanted as much voltage as possible, and the drop-off on the 3000's wasn't acceptable. Evidently they've alleviated those concerns to an extent. Can you tell us more about that?

cmattp
05-17-2003, 03:15 PM
Hey Austinwolv, you brought up a good point concerning the R/C industry, and using either Nicd, or Nimh cells.

Here's a scenario for some readers wanting to learn the diff. between Nicd and Nimh discharge characteristics. Let's say you have 2 of the same cell types (subc) and of course the nimh version will have atleast twice the capacity as the Nicd. If your application is a portable MP3 player your Nimh will perform twice as long as your nicd, easy as that. But let's say the application is a R/C car with a highly modified electric motor, similar to the motors in our beloved AEG's. When the motor is being ran there is a high amount of current being drained from the cells (up to 20 amps) as the Nimh cell tends to heat up internally very fast, the voltage begins to drop thus slowing your shots per second. Nimh cells hate heat.Like Wolv said if you let the cells recover from the high heat by letting them cool, you can very well slap it in your AEG and let tit rip again. Nicds are designed alot better for your high drain applications. Both of these chemestries have very similar discharge characteristics at a low rate of drain. But as soon as the Nimh sees a 1C, or 2C drain rate they will fall offwat quicker. check out this site for specs on all of sanyos cells they produce, has some nice diagramsand info on all their cells. http://www.sanyo.com/batteries/specs.cfm