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cdog4w
2007.03.16, 03:43 PM
Hi, I generally run lipos in my larger cars so I don't actually have that much nimh experience. Specifically the initial charge and conditioning portion. I have a mini-z AWD and just a single set of RS rechargeables currently, but just ordered 24 fujicell 1000's from ebay seller wosmile. Part of the impetus was an upcoming Kyosho demo at the NW Hobby expo and waiting for my single set of batteries to charge after a run was NOT an option :) I had read that these cells were a great deal on performance/price so I decided to go for it. I wasn't planning on posting about this until I saw spoon's thread about these cells going poof in a high quality charger... On to the questions:

1 - how to charge - I have a triton charger, but no charge tray as such. I know its "better" to use a quality charge tray like the PN or atomic, but would a simple 4x AAA pack from RS be adequate? I'm not really racing competitively since the scene in the area is underdeveloped. My concern would be more with making sure the cells aren't abused or imbalanced. What about building my own tray (maybe slice some pvc in half and have screw terminals at each end like the atomic line tray)?

2 - initial cycling, cell matching - Any suggested settings for cycling the cells to start? Should I cycle the cells individually to match them? (would take forever on a triton. I do have a single cell charge clip I made (U shape chunk with screws to retain the cell, I clip the charge leads to the screws on each end) for this purpose.

3 - worth buying a dedicated charger - Is it worth buying the lacross or maha chargers if I already have a triton? I like the idea of individually charged cells but the chargers aren't super cheap and I have a nice peak charger already.

4 - any other tips or advice would be welcome.

Spoon
2007.03.16, 04:43 PM
See responses below.

Hi, I generally run lipos in my larger cars so I don't actually have that much nimh experience. Specifically the initial charge and conditioning portion. I have a mini-z AWD and just a single set of RS rechargeables currently, but just ordered 24 fujicell 1000's from ebay seller wosmile. Part of the impetus was an upcoming Kyosho demo at the NW Hobby expo and waiting for my single set of batteries to charge after a run was NOT an option :) I had read that these cells were a great deal on performance/price so I decided to go for it. I wasn't planning on posting about this until I saw spoon's thread about these cells going poof in a high quality charger... On to the questions:

1 - how to charge - I have a triton charger, but no charge tray as such. I know its "better" to use a quality charge tray like the PN or atomic, but would a simple 4x AAA pack from RS be adequate? I'm not really racing competitively since the scene in the area is underdeveloped. My concern would be more with making sure the cells aren't abused or imbalanced. What about building my own tray (maybe slice some pvc in half and have screw terminals at each end like the atomic line tray)?

You can probably get away with a RS tray. The charging trays are pretty cheap though. You might want to get a discharger to make sure everything is balanced. I might be selling one soon but that's for another post.

2 - initial cycling, cell matching - Any suggested settings for cycling the cells to start? Should I cycle the cells individually to match them? (would take forever on a triton. I do have a single cell charge clip I made (U shape chunk with screws to retain the cell, I clip the charge leads to the screws on each end) for this purpose.

3 - worth buying a dedicated charger - Is it worth buying the lacross or maha chargers if I already have a triton? I like the idea of individually charged cells but the chargers aren't super cheap and I have a nice peak charger already.

Yes, I would get a dedicated charger. It's just easier to do the initial cycle that way. Also, with a single dedicated charger and your current charger with the tray you can charge two sets of batteries on race day. Then you won't be waiting.

4 - any other tips or advice would be welcome.

I don't think this post really addresses your primary questions but there's a little bit of useful info here.
http://128racing.blogspot.com/2007/01/battery-care.html
I should probably update it with break-in information. Gotta do more research now.

cdog4w
2007.03.16, 05:42 PM
Thanks for the quick reply. After your issue with the maha and having heard of so many other defective lacross (at least enough that more than one forum user has mentioned it), I'm hesitant to snag one despite your advice (which is sound advice). On the upside, 6 sets of race batteries should have me ready for race day even if I only have one charger running day of. That does bring up another question, what if I got an 8 cell charge pocket from radioshack and charged 8 at once on the triton? I could get even crazier and hook up 3 of those in series and charge all 24 cells at once :) I hear this actually works (mostly I've heard of people charging three 6 cell packs in series) but I don't think I'd try it!

You recommend a discharge tray, but isn't that a function of the 2 prime chargers listed here (the maha you have and the bc-900)? Ah, just read your blog and saw that it immediately jumps back into charge cycle after discharging.

I guess what I'm looking for now is some info on the difference between individual cell charging and pack charging since that is the prime difference between what I have and getting a new charger. Obviously individual cell charging is the optimal method, but that doesn't mean the pack charging isn't more than adequate so I'm just wondering what the finer distinctions would be.

Getting an individual cell charger would be totally worth it if only for the initial cycling if I wanted to do matched packs. Maybe sinister_y can chime in since he seems to run matched sets of cells.

Spoon
2007.03.16, 06:07 PM
You are correct about my suggestion about the discharger. I was going follow up by saying save your money on the discharger and just get a charger that does it all. One thing that is nice about the two chargers currently going head to head (LaCross and MaHa) is that customer service seems to be top notch.

If you are considering getting a separate charger I would highly recommend one of the current leaders. The ability to discharge and select charging rates is really worth it. There are plenty of quick chargers out there for less money but none that I know of that have half the features of the LaCrosse or Maha.

shuter
2007.03.16, 07:16 PM
I agree with Spoons advice. Buying a charger dedicated to properly preparing your AAA & AA NiMH batteries makes the most sense to me. The Lacrosse or Maha chargers will automatically discharge/charge your batteries for optimum performance and read out each cells individual ratings. There are some great peak chargers out there but they carry their own sets of problems. Charging a set of batteries or multiple sets of batteries in treys seems risky to me. If you have a weak cell in the pack you have no way of knowing it. You are likely to find out during the next race.

There has recently been a lot of time spent by a number of people on this site concerning these issues. Check out the other threads on chargers, discharging and batteries right here for additional information. If you wish to read further I recommend http://www.batteryuniversity.com/.

cdog4w
2007.03.16, 07:25 PM
Thanks for the advice. Seems like the MAHA is better overall but the lacrosse is a bit cheaper and easier to find?

It's a tough decision because I don't race seriously (yet, though I would like to) so its hard to justify $45-80 for a charger when I know the triton will do an ok job (just not as good as the aforementioned dedicated chargers). I guess I'll see how much interest there is at the upcoming expo and if a scene begins to form then I'll have to pick one up.

cdog4w
2007.03.20, 04:07 PM
Got the batteries on Saturday, haven't charged them yet. I have decided to start with my triton and a charge pocket for now, and might move on to the lacross or maha in the future. Seems 16hour 0.1C charge current break-in followed by a 0.2C discharge is the recommendation, but it also seems that has caused trouble for some users of the lacrosse and maha. I think I'll just do a normal 0.1C peak charge (5mV delta), followed by a 0.2C discharge and cycle them 2x that way. After that should I go to the full charge current? Any rec's on that? I was thinking 750-1000mA with a 5mV deltaV.

Very excited for this weekend.