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Justin
2010.01.10, 08:15 PM
Hi All,

been digging around for battery solutions and I came across the Atomic Mods LiPo battery which doesn't sound like a bad option. According to the description written on the page, it states that it will work with the standard electronics of any Mini Z, however it requires small modifications (which they claim aren't too hard).

Does anyone have a clear set of diagrams or instructions of what needs to be done for an MR-02 to run on LiPo?

Thanks in advance!

wildthing
2010.01.10, 09:10 PM
On my iwaver and mini Z, this is what I plan to do to wireup a lipo:

This is designed to be used on a lipo 10440 cylindrical type (10mm diameter, 44mm length) with a wiring modification that would make the set-up 2S2P or 2 batteries in series and 2 batteries in parallel.

This set-up will double the mAh capacity of the lipo and double the output voltage (7.4v).

I will be using a lipo battery with 360mAh that are wired parallel so that they become 720mAh. Then series connect two of these parallel batteries so that they they become 7.4v.

ianc
2010.01.10, 11:33 PM
This set-up will double the mAh capacity of the lipo and double the output voltage (7.4v).

Stock voltage is ~5V (4.8 nominal), so not quite...

ianc

wildthing
2010.01.11, 04:35 AM
^^ huh?!?

Isn't lipo have about 3.7volts each (full charge... so in series or 2S configuration... it would give out 7.4volts).

... these lipos are also charged full to 4.2v so two lipo in series would be 8.4v...

ianc
2010.01.11, 11:23 AM
Sorry, my bad, you are quite correct of course.

I thought you were saying you'd double the voltage of the stock (nimh) batts, but now that I actually READ it, I find that's not the case. :D

ianc

Traveler
2010.01.11, 02:29 PM
Hi All,

been digging around for battery solutions and I came across the Atomic Mods LiPo battery which doesn't sound like a bad option. According to the description written on the page, it states that it will work with the standard electronics of any Mini Z, however it requires small modifications (which they claim aren't too hard).

Does anyone have a clear set of diagrams or instructions of what needs to be done for an MR-02 to run on LiPo?

Thanks in advance!

I don't recommend this mod unless you have a runway to drive it on. Its way too fast to handle. :)

But if you choose to do it, there is a tutorial on it on A.M.s website!

Justin
2010.01.11, 04:45 PM
I don't recommend this mod unless you have a runway to drive it on. Its way too fast to handle. :)

By the sounds of it, you've done it to your car:p I know it'll be faster (consider the voltage bump of double), so I was expecting double the speed. But if you'll need an excessive amount of room to run it, then maybe it's not a wise idea.

Just found the link - must have skipped over it on the A.M. website (my bad). I was thinking it'd be an easier alternative to running NiMh rechargable AAA's as I already have a Li-Po charger. Decisions:confused:

cowboysir
2010.01.11, 05:13 PM
The voltage peak of a li-po does state 8.4volts but that is a no-load reading, just like some aaa's state a no-load voltage of 1.5v. When load is applied it functions from a 7.4volt basis.

As for doing this modification, you will find it very difficult to control on a RCP race surface. The lack of grip and higher peak speeds will make for crashes and spinouts at every turn.

Keep the li-po conversions for xmods which don't have real performance in the first place.;)

wildthing
2010.01.11, 06:16 PM
your observations on lipo about the speed burst is true...

on my rental iwavers I only use 1 cell of lipo (14430) per car and I have to bring down the EPA of the throttle to 55% so that the "newbies" who rent them won't crash it hard.

My AAA holder (keystone part # 170) arrived yesterday so I can now arrange me a good charging tray from my 10430 lipos. I will test my modified Iwaver and MA010 on my carpet tracks with a 21 feet straightway later and see if I can handle it well enough.

Justin
2010.01.11, 06:51 PM
Keep the li-po conversions for xmods which don't have real performance in the first place.;)

LOL :D

Everyone's basically talked me out of it now. I was going to use in on an indoor track where they run 1/18. If it's peaky and the EPA has to be dulled down, then there isn't much point to run with Li-Po's (except the long run time and even performance throughout). Furthermore, another thing I noticed is - there is no balance charger plug or I'm going blind since I skipped over the tutorial on the battery installation.

wildthing
2010.01.11, 09:04 PM
oh well... I still hate the charging of NiMh... I will probably stick with my lipos and simply learn how to it up properly. :D

Z06 Tony
2010.02.03, 02:08 PM
On my iwaver and mini Z, this is what I plan to do to wireup a lipo:

This is designed to be used on a lipo 10440 cylindrical type (10mm diameter, 44mm length) with a wiring modification that would make the set-up 2S2P or 2 batteries in series and 2 batteries in parallel.

This set-up will double the mAh capacity of the lipo and double the output voltage (7.4v).

I will be using a lipo battery with 360mAh that are wired parallel so that they become 720mAh. Then series connect two of these parallel batteries so that they they become 7.4v.

That is not right. You only double the voltage not the mAh. That would be magic. I use 2 3.7v 400Ah lipos wired to get 7.4v 400mAh. The people who are saying not to do it have never done it so they are NOT talking from experience. My track is this and the straights are perfect for 2s lipo

mikedw
2010.02.03, 02:20 PM
2S2P- that's four batteries not two.

color01
2010.02.03, 04:31 PM
7.4V LiPo is not unusuable, but you have to motor down to account for the voltage jump. A PN70t car with 2S LiPo can be geared up to the point that it walks away from Mod cars on NiMH. If you'll be racing against 1/18's then the infield shouldn't be too tight for the car (LiPos can make the car too punch for really tight infield sections), so a 2S2P setup would be fine.

For racing against other Mini-Z's, a 1S4P setup would be much more desirable. If you follow the current situation in 1/12 pan cars, the classes are moving from 4.8V NiMH to 1S (3.7V) LiPo, and motoring up a little bit to compensate for the reduced voltage. In a Mini-Z, a 1S4P setup will give you ridiculous runtimes, and you actually won't lose much speed at all due to the 4P LiPo having much lower internal resistance than the stock 4S NiMH config. Although you won't have quite the same punch with 1S4P LiPo, you'll also get much more consistent performance throughout a 5-minute qualifier or main (you could probably make it through a 20-minute main while everyone else would've dumped a long time ago). If serious competition is not your goal (PNWC, Atomic WC, Tekin, KO, etc. races all require NiMH batteries), then I'd personally go with 1S4P LiPo.



One more thing: I believe the 10440 cells are metal-cased lithium-ions rather than lithium-polymer cells. Watch the heat when you charge them up, and don't exceed a ~300mA charge rate per cell.

Z06 Tony
2010.02.03, 06:37 PM
7.4V LiPo is not unusuable, but you have to motor down to account for the voltage jump. A PN70t car with 2S LiPo can be geared up to the point that it walks away from Mod cars on NiMH. If you'll be racing against 1/18's then the infield shouldn't be too tight for the car (LiPos can make the car too punch for really tight infield sections), so a 2S2P setup would be fine.

For racing against other Mini-Z's, a 1S4P setup would be much more desirable. If you follow the current situation in 1/12 pan cars, the classes are moving from 4.8V NiMH to 1S (3.7V) LiPo, and motoring up a little bit to compensate for the reduced voltage. In a Mini-Z, a 1S4P setup will give you ridiculous runtimes, and you actually won't lose much speed at all due to the 4P LiPo having much lower internal resistance than the stock 4S NiMH config. Although you won't have quite the same punch with 1S4P LiPo, you'll also get much more consistent performance throughout a 5-minute qualifier or main (you could probably make it through a 20-minute main while everyone else would've dumped a long time ago). If serious competition is not your goal (PNWC, Atomic WC, Tekin, KO, etc. races all require NiMH batteries), then I'd personally go with 1S4P LiPo.



One more thing: I believe the 10440 cells are metal-cased lithium-ions rather than lithium-polymer cells. Watch the heat when you charge them up, and don't exceed a ~300mA charge rate per cell.

Thank you. I should have mentioned that I am using stock motor/gearing. The lipos I am using are the polymer so they do not have the metal casing. They do not get hot. Once I get a little better I will vid my laps wth the lipo against 3 other racers. We race every Sat. My track is the wide tiles so that helps as it is not as tight. My buddy is addicted and owns a snowplow/landscaping bus so he is calling me every day to race so I should get better faster. Raced 4 outa 5 days this week and racing tom and Sat.

doug01n
2010.02.03, 09:43 PM
I'm interested on that... what kind of cells do you guys use on a 1S4P config? Where can I buy these things? I really don't know... a picture would be great, if you guys may post it!

Thanks!

Z06 Tony
2010.02.03, 10:13 PM
I'm interested on that... what kind of cells do you guys use on a 1S4P config? Where can I buy these things? I really don't know... a picture would be great, if you guys may post it!

Thanks!

Sure its called a linear dicharge lipo. Most are not. The power does not dropoff. It is strong till it goes almost dead. Of course we never run them all the way dead. It is the 2nd from bottom(OVRSK40020C)-> http://www.rchobbyhelicopter.com/store52/agora.cgi?product=&user2=Batteries

They fit perfect in the stock spot on the MR-02 with the stock batt clips. Today I raced for 45 mins on a set. You need 2 to wire togeather. Cheapest speed upgrade you can do. I can post a pic of the batts in the car Thur.

BTW 1S4P means 1 cell 4 pieces so that is just what a stock configuration is. Mine is 2S. That is just 2 lipo cells 3.7v each for 7.4v.

herman
2010.02.04, 04:18 AM
oh well... I still hate the charging of NiMh... I will probably stick with my lipos and simply learn how to it up properly. :D

can't seem to understand why... there are different available chargers out there... from a simple 15 min... to an hour charger, to a 2 hour charger... really lots to choose from...

there are a couple of things that you have to consider when getting into this hobby... and one thing is... a good charger... :D

doug01n
2010.02.04, 07:47 AM
Thanks for the info! I1m almost buying 4 cells from HK, but i don't know if will it fit on the MR-03 battery case... I'm looking for practice cells, and the 3.7V lipo are interesting looking by this way.