Triton setup for 8 cells 1000 mAh - Please help :)

| Just curious, what physcial size are the cells?

Judging from 1000 mAh and NiMH, 4/3 AAA seems most likely, or it could be 2/3 A.

| >I have Triton charger and I was wondering if someone can help me with | > the settings for my battery pack. I have a NiMH 8 cells 1000 mAh pack. | > I made the battery packs after I bought the cells over the internet | > (1.2v 1000 mAh per cell). | >

| > The baterry pack doesn't last more than 4 to 5 minutes and after a full | > charge the display indicates an average of 640 mHA

Have you done the formative charge at C/10 for 15 hours or so? This is very important for getting new NiMH cells (and to a lesser degree, NiCd) cells to work properly.

You may be discharging the pack faster than it should be, and so you're hitting the low voltage cutoff when there's still capacity left in the cells. If so, this plane probably needs a larger pack, or at least a pack that can handle higher discharge rates. Or perhaps a smaller prop, to lower the discharge rate.

Try discharging the cells, then charge at C/10 for 15 hours or so, then discharge, then fast charge at 1C, then discharge with the Triton at 0.5C (500 mA) to 0.9 volts/cell (7.2 volts) and see what sort of capacity you get.

| > I used solder wick to make the connections between the cells. Do you | > think this might be a problem?

No, solder wick works great, especially if you coat the entire wick in solder. But if you soldered too long, you may have damaged the cells.

Each cell is a AAA.

CB

First, RTFM.

The Triton does a good job of figuring out what rates a particular cell type can reliably use. AAA NiMh simply do not like high rates at all, and while they will 'charge', the capacity will never be what you might expect.

Use NiMh Auto and let theTriton set the rates. The charger does a good job of figuring out what the cells can give and take.

Get rid of anything over 200 mAh for AAA cells, and set the top off rate to minimum (100 mAh).

IMHO AAA NiMh cells rated for 1000 mAh are deceptive advertising or creative marketing, whichever you prefer.

Above all, mind the cell temperatures. It's very easy to 'cook' AAA NiMh cells. BTDT.

First off, ditto what Doug said. I had a similar problem with a couple NiMH packs when I first got them. Turned out the packs were never being fully charged. I was using the pre-made charge cords sold by Tower Hobbies. Really small wire. They worked OK for small packs at a low charge rate, but when I used them on larger packs at a higher rate it seemed that the voltage drop across the charger leads would cause a false peak and the Triton would think the cells had peaked and were fully charged. I made up my own charge leads out of larger wire, 18 gauge, and the problem went away. Don't know if this is your problem, but it could be. Hope this helps and remember the C/10 initial charge is very important for NiMH cells. That would be 100ma for your 1000 ma cells. Try cycling the pack at discharge = 200ma, charge = 100ma about 4 or 5 times. Yes, it'll take several days. You didn't say what brand the cells were. There are some crappy ones out there that will never give you their rated capacity. Paul

Thanks to all for your help.

This is the link to the batteries I am using:

Titanium NIMH Rechargeable Battery

I am going to try recicling the batteries and let's see what happens.

Thanks again.

CB

| This is the link to the batteries I am using: | | Titanium NIMH Rechargeable Battery | |

Ok, but the largest capacity of AAA NiMH cells that I've heard of up until now was 800 mAh. Apparantly these people and others are now selling 1000 mAh cells, so under some ideal conditions you might actually get 1000 mAh out of them.

However, these are not designed for high discharge rates like your helicopter requires. I don't exactly know how much power it requires, but it's probably around five amps.

They get high capacity out of these cells by making the plates smaller

-- so the internal resistance goes up. These cells probably aren't good for more than three amps of current draw.

| I am going to try recicling the batteries and let's see what happens.

It may help, but I doubt it'll make these batteries work well. If they get hot during normal flight, they're not really good.

To add to Doug's statement.

Rule of thumb in battery design. In a given cell size, high capacity is gained at the expense of discharge current capacity. The plates are smaller in surface area but much thicker so the internal resistance is higher. More active material, less substrate (conductive material) to act as current collector.