Charging/Discharging Batteries

[godale03]

Hey Guys,

I am looking at upgrading my battery charger to the new Super Brain 959. The only type of packs I will be charging is NiMh and NiCd. I do not own any LiPo packs. My question is this.... What is the proper way to charge discharge your batteries? I have never "Cycled" a batter pack in my life. The charger I have now is a "Plug N Play" and I just plug the battery in and go. I understand this is not a great practice. Winter is coming and I want to be able to properly care for my packs. So I guess what I am looking for is advice on how to properly do this. What settings do you charge/discharge receiver packs, and your Stick packs? I have spent alot of money on batteries and would like to keep them running peak as best I can. I have also heard that the plug and play system has a tendancy to False Peak alot..... is this true? Thanks for the help guys.

Tom

 

[HeartBreak]

Depends on the configuration of the cells in the pack. Is it a sport "stick" pack, like those that are priced around $15 at Rat Shack, or are they the side-by-side packs, with the individual cell contacts exposed at the sides?

If they are the side-by-side packs, then the maintenence is a lot easier. What I do is discharge the pack to around 6.6v (1.1v a cell) total, using a deans blackbox and 10 1157 Automotive taillamp bulbs, wired in parallel. This prevents the chance of over-discharging and causing a cell to go into "reversal" (chemically shorting out inside the cell, rendering it useless).

After the pack is "dumped", I let it cool, then place it on an equalising tray, such as Trinity's Realtime 2 (oldie buy goodie), which takes the cells down even further (.9v a cell, if I remember the numbers right).

After a further cooling period, letting the pack cool to room temperature, I charge. Now, here is where the routine for nimh varies from nicad.

Nicad, I store right after equalising, since it has a tendency to "stabilise" itself back to around 1.0v a cell or so (provided it wasn't taken down way too far, or the cell isn't too old).

Nimh, I charge to approximately 40% before storing. I have found that nimh is the total opposite of nicad, in that it will go flat (think of it as soda pop) over time, draining itself.

 

[godale03]

Thanks for the info Heartbreak. The stick packs I am working with of the $50 or so variety. In the T4 I am using SMC's, I believe they are 4200's and for the 18t I am using those new Reedy packs. They are side by side, but are in a srink wrap. I do not solder my own batteries... yet. The reciever packs are standard Orion hump packs.

Tom

 

[HeartBreak]

I wouldn't worry too much about maintenence on reciever packs. Granted, I discharge my reciever packs before charging them, but it's really an unneeded step, since they're cheap and easy to replace (compared to the larger electric packs). Same with the mini's packs. The discharger I use is a home brew unit; I'm sure somewhere out there, there is a commercially available unit.

You do have to worry about discharging at too high of a rate, especially on the 2/3A cells of the reciever pack and minis' pack. If you use a discharger like Deans Blackbox (a little hard to find nowadays), you can connect it to the Deans lightbulb assembly, and that will provide the correct amperage.

Now, as for your SMC's, you can cut little holes in the shrink wrap, to allow the tray to touch the cells' contacts. The others, I would just use 'em as practice packs, until they wear out and then upgrade 'em as they're being replaced.

On my cells, all I do, aside from using good quality battery bars (Deans bars are pretty good), is shoe-goo the cells to each other.

Also, I do a little "cheating" with my packs; I solder 'em as saddle packs, even though they're used in an RC10B3/T3. This allows me to split the weight balance.

 

[godale03]

Wow! I think I got all of that! LOL I will have to read that a few times until I understand it all.

Now as far as a charger... can you recomend a good one? Is the 989 ok? Thanks

Tom

 

[HeartBreak]

Actually, the 989 I would stay away from. The absolute Cadillac of chargers is the Turbo35, but that's grounds for divorce. I would actually recommend a good Novak Millenium off ebay, and a decent power supply for it (Novaks' N-Power would be sufficient). It'll charge anything you throw at it, nimh or nicad.

As for dischargers; deans blackbox and discharger light bar set is the way to go.

Those are my preferrences, I'm sure there's a better setup out there.

 

[Monkey Wrench]

Any chance I can just send you my packs and you take care of them? Man, great stuff, HB, thanks!

 

[HeartBreak]

LOL - it comes from years and years in electric racing. I started back when the Gold tub RC10 was common. I had one of those and a JRXT. I learned all my battery knowledge through trial and error (mostly error) and reading about what guys like Cliff Lett and Ernie Provetti would recommend, and giving that a shot.

I have no experience with LiPo; I know they can be dangerous in the wrong situation.