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View Full Version : Max voltage for MR03/MA020 Sports - is it lipo capable?


littlebuddha
2015.12.17, 08:02 PM
Hi guys, I have a ma020 sports and am thinking of using nizn aaa (1.8v cells) or lipo. Does anyone have experience with the sports - can its board handle the extra voltage without frying? thanks.

byebye
2015.12.17, 08:18 PM
Hi guys, I have a ma020 sports and am thinking of using nizn aaa (1.8v cells) or lipo. Does anyone have experience with the sports - can its board handle the extra voltage without frying? thanks.

I honestly couldn't tell you but I'm curious to know myself. I've put 7.4 lipo's to a stock MR-03 brushed board and had no issues.

littlebuddha
2015.12.18, 09:11 AM
Ya I asked Kyosho and their standard answer was don't put anything in it other than nimh/alkaline as stated in the manual, or else warranty is void - which I did not find very useful...

I honestly couldn't tell you but I'm curious to know myself. I've put 7.4 lipo's to a stock MR-03 brushed board and had no issues.

byebye
2015.12.18, 04:14 PM
Ya I asked Kyosho and their standard answer was don't put anything in it other than nimh/alkaline as stated in the manual, or else warranty is void - which I did not find very useful...

Warranty? Not worth my time imo.

cowboysir
2015.12.18, 07:58 PM
The sports series have a similar fet level as the AM and FM boards of olden days. Those were very sketchy boards at anything other than 4.8 volts....not only a high probability of blowing the drive fets the steering was super jittery.

Is it worth the risk? You decide.

littlebuddha
2015.12.21, 09:51 PM
Well I bit the bullet and put the nizns into my ma020s:eek:! luckily nothing is friend and has tons of power - pretty happy with the setup. I'm only running it around my house - not sure how it would do with an xpeed motor in a racing environment but so far so good (fingers crossed!).

DMALMAD
2015.12.21, 11:51 PM
Well I bit the bullet and put the nizns into my ma020s:eek:! luckily nothing is friend and has tons of power - pretty happy with the setup. I'm only running it around my house - not sure how it would do with an xpeed motor in a racing environment but so far so good (fingers crossed!).

You will probably fry your steering fets eventually, and those fets are tiny and hard to replace unless you have profesional equipment.

littlebuddha
2015.12.22, 01:43 AM
Thanks for the warning - yes will have to do a longer term follow up to see how it goes. The 1.8v is max only fresh off the charger, I'm hoping it drops pretty fast to 1.4-1.5 which is alkaline level after use. Not worried about it on my MRO3VE, but will keep you guys posted on the MA020S.

You will probably fry your steering fets eventually, and those fets are tiny and hard to replace unless you have profesional equipment.

DMALMAD
2015.12.22, 02:47 AM
Actually the only steering fets I fried were on my ve and that was even worse luck because no one locally had the right fets to replace them as the steering fets in the VE are different than the ones on the 03 board.

But Yeah just keep an eye out, if the steering starts to get real jittery than they are starting to give out and just switch back to nimh on that board.

littlebuddha
2015.12.22, 11:49 AM
Wow for the VE as well? what battery were you running? Nizn or Lipo?

its crazy that in 2015, with the AMZ and even the cheap mini q3 being able to handle lipos that kyosho has not caught up. If the awd sports board does fry I may try to replace it with a cheaper board from bangood. I may just have to go with the standard nimh in the end (sigh)

Actually the only steering fets I fried were on my ve and that was even worse luck because no one locally had the right fets to replace them as the steering fets in the VE are different than the ones on the 03 board.

But Yeah just keep an eye out, if the steering starts to get real jittery than they are starting to give out and just switch back to nimh on that board.

TheSteve
2015.12.22, 12:39 PM
The FETs are cheap and easy to replace by anyone with a decent soldering iron and some surface mount experience. I'd just run the higher voltage if that is what you want. Just make sure the end points are adjusted properly so your steering isn't binding at all.

DMALMAD
2015.12.22, 08:11 PM
Wow for the VE as well? what battery were you running? Nizn or Lipo?

its crazy that in 2015, with the AMZ and even the cheap mini q3 being able to handle lipos that kyosho has not caught up. If the awd sports board does fry I may try to replace it with a cheaper board from bangood. I may just have to go with the standard nimh in the end (sigh)

It was with 2s lipo not NIZN but still the higher voltages put a strain on the boards. Also the banggood board is not lipo compatible either, I would think that board would fry sooner than the sports because of the poor quality of components.

As far as replacing the steering fets go I have seen it done but I wouldn't call it easy. I have fetted my fair share of throttle fets but those steering fets are just so tiny and surrounded by a million different other components so unless you have a real steady hand and a lot of experience I would just replace the board and not kill yourself over it. Usually the boards that fry the steering fets and have them replaced fry the steering fets continually and I have seen this happen on a pretty regular basis. But if you are good with a soldering iron it is just a matter of buying the right ones and swapping them out (I think there is a thread somewhere about which fets to use).

Jshwaa
2015.12.23, 08:30 AM
For those that would be inclined...

To mitigate the ill effects of increasing the voltage on steering, you could add between 1 and 2 ohms of resistance in series with either of the wires leading to the steering motor. This would limit the current to the steering motor and keep it from driving past the steering target point, which is what causes the jitter and damages the steering FET's.

Because you really only want the increased 'power' of increasing the voltage to go to your motor, and not to your steering.

The pic below shows an MR-03 board. The steering motor wires are the red and blue.

http://i83.photobucket.com/albums/j314/Jshwaa/Mini-Z/DSCN2326.jpg (http://s83.photobucket.com/user/Jshwaa/media/Mini-Z/DSCN2326.jpg.html)

littlebuddha
2015.12.30, 12:17 AM
Thanks everyone for the helpful insights - so to summarize from what I can gather:

1) even 1.6v cells (.4v over the alkalines for even a limited amount of time before battery drain) can result in damage over time (especially to the steering fets)

2) adjusting the steering endpoints so that there is no binding/strain on the servos won't help.

3) unless you want to solder - stick with nimh :)

DMALMAD
2015.12.30, 03:16 AM
Thanks everyone for the helpful insights - so to summarize from what I can gather:

1) even 1.6v cells (.4v over the alkalines for even a limited amount of time before battery drain) can result in damage over time (especially to the steering fets)

2) adjusting the steering endpoints so that there is no binding/strain on the servos won't help.

3) unless you want to solder - stick with nimh :)

I mean whether you want to run lipo or NiZn or nimh soldering is a good skill to have and is just a matter of tools and patience. I think that adjusting the endpoints does make a big difference though, I personally used to crank up my endpoints a ton to compensate for the radio I had so that was one of the main reasons that my boards would go with lipo. However I do not think you would really be missing out if you just stick with nimh. The nizn supposedly have shorter life spans and generally aren't as sturdy as the nimh. If you want more speed put more motor and stick with the batteries that are indestructable, still too slow replace the throttle fets (there is a pretty good tutorial of this on youtube created by the old atomic mods guys).

But yeah I guess if you aren't comfortable soldering than nimh would be the best bet for longevity.

arch2b
2015.12.30, 10:25 AM
read the reviews on the zinc cells, they are generally horrible. this would explain why you can only find them in bulk and very cheap as they have since been discontinued according to various reports and retailers selling off old stock. i have a couple sets but do not have a charger they will work in, if your domestic US, email me and i'll send you some sets. what you would find on ebay would be no better than the cells i have really as they are all of the same age. can't garuantee they would work anymore though, no more so than buying from ebay or amazon either. awesome power from them but they are junk cells for the most part.

littlebuddha
2015.12.30, 10:42 PM
Thanks yes I think I will be returning the nizns to amazon - have had some cells that did not charge the second time around but it was (really) fun while it lasted. One thing - 3.3vx2=6.6v life are safe for the Zs? In that case Nizn which are 1.6vx4=6.4v should be fine as well no?

I'm planning on getting the Peak 900hv and (after some research) the OPUS BT-C700 charger. Any other recommendations?

On a sidenote - I actually managed to screw up my front diff of the MR03s just messing around on the wooden floor - its crazy since it has drift tires so despite the lack of grip it shows how weak the stock parts are. The front right plastic universal came apart under load, binding the wheel- which I did not immediately notice. After a few full throttle bursts the front diff was gone. One a positive, it is acting like a spool now :) I'm pretty sure this would have happened with nimhs inevitably.

I'm getting the MBW002 (hard diff for the mini z buggy which should fit) and should provide some maintenance free playtime for the sports. I really like how the stock diffs feel. Already ordered the 3racing universals - I think those are the only two upgrades I'm planning for the time being since I'm going to spend some extra on a charger.

Seems you are in the DC area as well. Any nearby metro accessible stores that stock mini z parts?


read the reviews on the zinc cells, they are generally horrible. this would explain why you can only find them in bulk and very cheap as they have since been discontinued according to various reports and retailers selling off old stock. i have a couple sets but do not have a charger they will work in, if your domestic US, email me and i'll send you some sets. what you would find on ebay would be no better than the cells i have really as they are all of the same age. can't garuantee they would work anymore though, no more so than buying from ebay or amazon either. awesome power from them but they are junk cells for the most part.

arch2b
2015.12.30, 11:25 PM
not that i am aware of unfortunately. hobby works is about 20 minutes outside the city. plenty of guys in the area with stuff and someone is always selling something.

byebye
2015.12.31, 09:28 AM
Thanks yes I think I will be returning the nizns to amazon - have had some cells that did not charge the second time around but it was (really) fun while it lasted. One thing - 3.3vx2=6.6v life are safe for the Zs? In that case Nizn which are 1.6vx4=6.4v should be fine as well no?

I'm planning on getting the Peak 900hv and (after some research) the OPUS BT-C700 charger. Any other recommendations?

On a sidenote - I actually managed to screw up my front diff of the MR03s just messing around on the wooden floor - its crazy since it has drift tires so despite the lack of grip it shows how weak the stock parts are. The front right plastic universal came apart under load, binding the wheel- which I did not immediately notice. After a few full throttle bursts the front diff was gone. One a positive, it is acting like a spool now :) I'm pretty sure this would have happened with nimhs inevitably.

I'm getting the MBW002 (hard diff for the mini z buggy which should fit) and should provide some maintenance free playtime for the sports. I really like how the stock diffs feel. Already ordered the 3racing universals - I think those are the only two upgrades I'm planning for the time being since I'm going to spend some extra on a charger.

Seems you are in the DC area as well. Any nearby metro accessible stores that stock mini z parts?

U joints are a definite upgrade for the awd. I've typically used the stock diffs but only because I get bored with the awd and just drift only. I currently have a ball diff but my awd is in pieces with no plans to rebuild at the moment.

Kris

littlebuddha
2015.12.31, 03:25 PM
thanks guys- yes seems like I will have to get some extra universals then - hope the 3racing ones are good. I also ended up getting the orion 1100rt nimhs, I think these will be good for the brushless/x-speed motors and maybe be a little easier on the drivetrain than the peak 900hv.

Btw-Is there a forum/post where local DC guys post stuff for sale? I've been interested in getting a mini z buggy, some autoscales and maybe hopups for the mr03/ma020. Would be awesome to just meet up locally to buy/sell as many places don't have items in stock.

arch2b
2015.12.31, 06:18 PM
our subforum is HERE (http://mini-zracer.com/forums/forumdisplay.php?f=64). no for sale thread per sae, best to show up and ask around. you can check with the Remnant (http://mini-zracer.com/forums/forumdisplay.php?f=186) guys as well.

mleemor60
2015.12.31, 06:21 PM
He may be talking about the "BC" group thread.

littlebuddha
2016.01.20, 05:32 PM
hi guys - quick update. I ended up getting a nice charger (Opus) and some peak nimhs - working quite nicely on my MA020VE- plenty of power- definitely does not need the nizns. For the MA020S I'm keeping with the nizns - they are working very well with the stock motor- love the scoot. Will see how it goes in the long run but the batteries are charging/running well for the time being (fingers crossed :) Looking forward to getting my MB010 soon as well.