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-   -   Mugen MTX-3 (https://www.rctech.net/forum/nitro-road/7666-mugen-mtx-3-a.html)

stefan 01-13-2004 05:42 PM

I finally found some Sanyo 5/4th AAA cells, rated at 830 mAh.

They fit the MTX3 battery tray perfectly and the take 950 mAh charge.

That should do for the longer mains...

Manticore 01-13-2004 05:43 PM


Originally posted by stefan
I finally found some Sanyo 5/4th AAA cells, rated at 830 mAh.

They fit the MTX3 battery tray perfectly and the take 950 mAh charge.

That should do for the longer mains...

you cannot take charge mah as true capacity

you should take discharge mah as reference capacity only.

OZDC 01-13-2004 05:58 PM


Originally posted by Taylor-Racing
Montecore. :nod:

But I've no idea what those blocks do . . and you've only got three weeks. :lol:

Oh well, have to work it out for myself:confused:

Now lets get back to trying to chat up FFG ;)

DC

stefan 01-13-2004 06:11 PM


Originally posted by Manticore
you cannot take charge mah as true capacity

you should take discharge mah as reference capacity only.

That's not true Manti.

These cells take about 150 mAh more charge as the regular AAA cells and that's exactly how they are rated.

When you discharge, it absolutely depends on what amperage you arre using.

When I charge at 0.8 amp and discharge at 0.8 amp, I get 820 mAh out of them.


At 1 amp they only show 740.

Manticore 01-13-2004 07:55 PM


Originally posted by stefan
That's not true Manti.

These cells take about 150 mAh more charge as the regular AAA cells and that's exactly how they are rated.

When you discharge, it absolutely depends on what amperage you arre using.

When I charge at 0.8 amp and discharge at 0.8 amp, I get 820 mAh out of them.


At 1 amp they only show 740.

tell me stefan, when you use your pack on your car, is it charging or discharging? :D :D :D

why the read out is usually higher on charging is that you have additional time consumed besides the real charging period. such as peaking. and your charger calculate the total charging mah in relation to total "charge" time and gives the "total mah charged" which is overstated.

why your read out on discharge is different with different amp? it is because when you use higher amp for discharge, your battery pack overall volt drops much faster then lower discharge amp.

There are a few more factors that hinder the charge and discharge time and they are vary from cell to cell such as internal resistance. but then I am not a battery expert and this is all i know about charge and discharge time.

AMGRacer 01-13-2004 08:02 PM


Originally posted by stefan
That's not true Manti.

These cells take about 150 mAh more charge as the regular AAA cells and that's exactly how they are rated.

When you discharge, it absolutely depends on what amperage you arre using.

When I charge at 0.8 amp and discharge at 0.8 amp, I get 820 mAh out of them.


At 1 amp they only show 740.

Manticore is correct. All chargers calculate "charge mah capacity" by merely calculating how long a particular amperage rate was going into the battery. Eg, 1 Amp for 1 Hour = 1000 mah. That does NOT mean that is how much charge your cells takes. Cell temperature, internal resistance of the batterys and just "natural fluctuations" almost always means that LESS than the indicated charge figures is absorbed by the cells.

The discharge figure is the only figure that you can trust to determine how much capacity a particular pack has. Also not you can fake this out with small packs like nitro receiver packs by running a very small discharge load. A RX pack will indicate more mah when discharged at 0.1 amp rather than 2 amps. Another thing which makes reading discharge times and mah ratings almost useless on RX packs.

Taylor-Racing 01-13-2004 08:12 PM


Originally posted by OZDC
Guys,

New to the MTX3, I started searching through the topic and gave up.

I'd like to know the theory behind the rear blocks (A-A etc) and the adjustable ackerman and how they change the car.

thanks

DC

It's OK DC, I've figured it out.
One set of those blocks works very well and the other two don't.

And the ackerman settings are there so you can't get the understeer dialed out.
;)

Taylor-Racing 01-13-2004 08:15 PM

AMG, Manti, whoever,

How long would you expect a 700Mha RX pack to last on a typical race day?
I know there are a wide bunch of variables which makes any accuracy impossible, but how long?

tl2111 01-13-2004 08:22 PM


Originally posted by Taylor-Racing
AMG, Manti, whoever,

How long would you expect a 700Mha RX pack to last on a typical race day?
I know there are a wide bunch of variables which makes any accuracy impossible, but how long?

Gav

if the battery in good condition, it should last at least 30min final.

Tommy

OZDC 01-13-2004 08:24 PM


Originally posted by Taylor-Racing
AMG, Manti, whoever,

How long would you expect a 700Mha RX pack to last on a typical race day?
I know there are a wide bunch of variables which makes any accuracy impossible, but how long?

To paraphrase; 'quid pro quo' my dear Taylor.

I usually get well over an hour with my 700mah pack.
KO mars with 1 digital servo.

But I always top up b4 the final.

DC

Taylor-Racing 01-13-2004 08:30 PM

OK, if DC reckons about an hour and Tommy says at least 30 minutes then the 45 minute final at the Vic's shouldn't be a problem, eh.

What am I talking about. :weird: . . . we're only going to need to worry about the 10 minute heats. :lol: :lol:

You comig to visit, Tommy?

AMGRacer 01-13-2004 08:32 PM


Originally posted by Taylor-Racing
AMG, Manti, whoever,

How long would you expect a 700Mha RX pack to last on a typical race day?
I know there are a wide bunch of variables which makes any accuracy impossible, but how long?

My experiences long ago:

1000 mah pack with 2 x Hitec 605MG servos (non digital) ran for well over 1 hour easily. I never ran out.

More recently:

My 650mah pack which discharges only 470mah (yep it is trashed) lasts me for 3 x 5 minute heats + 3 x 3 minute warmups and a few more minutes of tooling around. At the track where I run a 10 minute final + warmup it lasts for that as well. This is with 2 digitial 9550 Futabas. My charger usually pulls 100mah out of it after 3 x 5 minutes + 1 x 10 minute final. It will not do a 30 minute final without a topup.

AMGRacer 01-13-2004 08:40 PM


Originally posted by Taylor-Racing
OK, if DC reckons about an hour and Tommy says at least 30 minutes then the 45 minute final at the Vic's shouldn't be a problem, eh.

What am I talking about. :weird: . . . we're only going to need to worry about the 10 minute heats. :lol: :lol:

You comig to visit, Tommy?

An advantage of the V1RR Evo is that you can choose to run a AA sized hump pack. These are available at 1100 and even 1200 mah capacities for very long races. They add 40g or so however.

Manticore 01-13-2004 08:46 PM


Originally posted by AMGRacer
An advantage of the V1RR Evo is that you can choose to run a AA sized hump pack. These are available at 1100 and even 1200 mah capacities for very long races. They add 40g or so however.
but the added 40g is disadvantage !! so it is give and take. :ha: :ha:

tl2111 01-13-2004 09:53 PM


Originally posted by Taylor-Racing
OK, if DC reckons about an hour and Tommy says at least 30 minutes then the 45 minute final at the Vic's shouldn't be a problem, eh.

What am I talking about. :weird: . . . we're only going to need to worry about the 10 minute heats. :lol: :lol:

You comig to visit, Tommy?

Gav

Wouldn't be able to make it this year, maybe next time
well Nimh needs look after otherwise it fail short badly, I use 2 KO Fet servo on my car, it can easily do 20mins practice then 3x5 mins heat and top up for 30 mins final, usually take 400-500mah
hope this help. btw my battery is 700mah


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