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Mad Zero

So It's Another Lipo Post...

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Yeah yeah I used the search button to placate the shouty people, posted in the 'LiPo basics what do I need to know?' thread but there was no replies so I'm re-posting it here:

I'm not too concerned with ultimate performance so is there a type of LiPo pack I could buy to just use in place of 3800 NiMH sticks to get a more consistent run and longer run-times? ..or would I have to work out the current drain of all my motor/ESC setups and buy a different LiPo pack for each to suit? I'm currently running silver cans with Tamiya ESC's, twin silver cans with an LRP F1 ESC, Novak 5800SS brushless, various other random 19T motors & ESC's.. you get the picture!

Also, while I'm here I've just inherited an Overlander Sport 2200 3S 11.1v 25C pack - what can I use that for? ..or will it be a paperweight? :P

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for the most part any lipo with decent mah and 20c or more discharge speed will run anything you have. the issue is fitment.

there are some lipos that have rounded hardcases so they are the same size as a 6 cell nicad or nimh pack.

you'll need a low voltage alarm for ecs's without a low voltage cut off.

turnigy, tenergy and duratrax make the rounded harcases IIRC. i do use a couple of soft case 3000 mah 30c turnigy lipos, i have gotten about 20 minute run times in my df01 with a 9t ezrun, but the batt barely fits.

that novak you have should ba able to use the 3s you have.

you also need a charger that can charge lipo and a balancer if the charger doesn't include one, but i'm sure you know that already.

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for the most part any lipo with decent mah and 20c or more discharge speed will run anything you have. the issue is fitment.

there are some lipos that have rounded hardcases so they are the same size as a 6 cell nicad or nimh pack.

you'll need a low voltage alarm for ecs's without a low voltage cut off.

turnigy, tenergy and duratrax make the rounded harcases IIRC. i do use a couple of soft case 3000 mah 30c turnigy lipos, i have gotten about 20 minute run times in my df01 with a 9t ezrun, but the batt barely fits.

that novak you have should ba able to use the 3s you have.

you also need a charger that can charge lipo and a balancer if the charger doesn't include one, but i'm sure you know that already.

Thanks for the info! So it's more down to whether it will physically fit then right well I'll get my plane pack into the E'storm no sweat so next problem will be if it fries my Spektrum RX with the extra voltage?

Yes I have a LiPo balance charger but I was wondering, rather than a low voltage alarm, is there such a thing as a low voltage shut-off that cuts full power and just leaks enough through to run it back to the driver?

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low voltage cut off will leave you enough juice to limp it back to you. for example with my ez run i notice a 50% power cut, i just drive it back and change batts.

i think all brushless esc's have a low votage cut off, i know the high end ones do and so do the ez's and xe's.

voltage to the rx is supplied by the esc so it's more like 4.5 volts to the rx, no matter how much voltage the pack has.

EDIT:

i resisted going lipo for a while, but i'm glad i made the switch. the run times are better the power is crazy and as long as you balance the cells last a long time.

you can also store them charged, unlike nimh.

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low voltage cut off will leave you enough juice to limp it back to you. for example with my ez run i notice a 50% power cut, i just drive it back and change batts.

i think all brushless esc's have a low votage cut off, i know the high end ones do and so do the ez's and xe's.

When I said a low voltage shut-off I mean to protect the battery from being discharged too low - is this what you're saying is built into most ESC's?

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Shame you can't edit topic titles :ph34r:

Paul.

Well if you could, how would you edit it? :P

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Oh, I know you didn't mean it, perhaps you should turn on the UK news...

Paul.

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Oh, I know you didn't mean it, perhaps you should turn on the UK news...

Paul.

Jeez I'm sorry I just checked the news as you said - I have PM'd Andy to see if he can edit it for me :P

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I know you and know you wouldn't do it intentionally, hence the 'shame you can't edit titles' bit :P

P.

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I know you and know you wouldn't do it intentionally, hence the 'shame you can't edit titles' bit :P

P.

Cheers Paul I feel bad right now!

SORRY EVERYONE - I'M DOING ALL I CAN TO GET IT CHANGED!

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I tried to PM first, but only got this:

"Welcome to your messenger

The following errors were found

This message can not be sent because the recipient has their personal messenger disabled or they are in a member group not allowed to use the personal messenger.

This personal message has not been sent"

Don't beat yourself up, it happens, it would only be bad if you meant it, which you don't.

P.

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The title will get sorted,it`s obvious you didn`t know.

Fortunately it is a sub title.Don`t worry.

I have emailed Chris and all mods[via the report button] directly as well.

regards,

Simon.

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When I said a low voltage shut-off I mean to protect the battery from being discharged too low - is this what you're saying is built into most ESC's?

yes.

what did i miss here :)

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what did i miss here

Nothing to worry about,the thread title was a bit too close to a very very unfortunate news item here in the UK.

So it was deleted to avoid any offence or misunderstanding,that is all.

BR,

T.

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..what did you miss?

Only the faux pas of the year that's all :)

So, would anyone like a stab at my original question? :)

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i figured out the faux pas, sad story indeed.

i did reply to your last question though.

i know lipo seems a bit complicated but it's really not. it's pretty simple once you get the lingo and concept down.

here's my last .02 on the subject (i think lol)

alot of guys want to go with these really fast brushless motors, very high kv. the problem with high kv motors is they aren't very efficient and can over heat quickly. the solution is using lower kv motors at a higher voltage.

all in all lipo is great.

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i figured out the faux pas, sad story indeed.

i did reply to your last question though.

i know lipo seems a bit complicated but it's really not. it's pretty simple once you get the lingo and concept down.

here's my last .02 on the subject (i think lol)

alot of guys want to go with these really fast brushless motors, very high kv. the problem with high kv motors is they aren't very efficient and can over heat quickly. the solution is using lower kv motors at a higher voltage.

all in all lipo is great.

Yes, sorry I'm having a senior moment here mate, I read your original answer as if you were solely talking about the plane pack I'd inherited - now I've re-read it I can see the answer to my question! ..doh!

Anyhow it seems that by being tight-fisted and hanging on to my old Novak 5800 system, and being lucky in scoring a free 3 cell pack I've got it right (at least for one car) then - a low kV motor with a higher voltage battery! Result! :)

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I know this isn't a LIPO post, but I was wondering if the requirement calculations for LIPO also correspond to NiMH batteries?

I ask because I recently built a Tamiya Landcruiser CR-01 kit and opted to use the Hobby Wing EZ Run Brushless Carwler Combo (ESC and motor). I didn't want to use one of the 55T Brushed motors because I don't plan on any serious crawling and wanted a bit more wheel speed. The specs on the combo I bought are:

35A ESC

32T Brushless and sensorless motor

1200Kv Motor

I am running the above with a 6cell 7.2V NiMH stick pack (Orion Rocket Pack) 2700MaH. Wheel speed is quite low and is actually faster in reverse for some reason. The motor seems to have a lot of power and no cogging (which was a concern of mine with the sensorless motor). I'm not aware of a pinion upgrade for this model for a bit more wheel speed, and in the time I ahve used the kit, ESCtemps or motor temps have not been an issue. I am wondering if I would notice more wheel speed with higher voltahe (i.e. LiPO batteries) but am reluctant to go that route due to the cost of purchasing the batteries and the charger at this time. Would upgrading to a higher MaH battery make any difference or is the issue the amount of amps that the NiMH battery can supply? Sorry for all the questions, I have been reading but am a newb when it comes to current, demands, and voltage etc.

Thanks,

Mark

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I know this isn't a LIPO post, but I was wondering if the requirement calculations for LIPO also correspond to NiMH batteries?

I ask because I recently built a Tamiya Landcruiser CR-01 kit and opted to use the Hobby Wing EZ Run Brushless Carwler Combo (ESC and motor). I didn't want to use one of the 55T Brushed motors because I don't plan on any serious crawling and wanted a bit more wheel speed. The specs on the combo I bought are:

35A ESC

32T Brushless and sensorless motor

1200Kv Motor

I am running the above with a 6cell 7.2V NiMH stick pack (Orion Rocket Pack) 2700MaH. Wheel speed is quite low and is actually faster in reverse for some reason. The motor seems to have a lot of power and no cogging (which was a concern of mine with the sensorless motor). I'm not aware of a pinion upgrade for this model for a bit more wheel speed, and in the time I ahve used the kit, ESCtemps or motor temps have not been an issue. I am wondering if I would notice more wheel speed with higher voltahe (i.e. LiPO batteries) but am reluctant to go that route due to the cost of purchasing the batteries and the charger at this time. Would upgrading to a higher MaH battery make any difference or is the issue the amount of amps that the NiMH battery can supply? Sorry for all the questions, I have been reading but am a newb when it comes to current, demands, and voltage etc.

Thanks,

Mark

Perhaps something is wrong if your car runs faster in reverse. I don't know what it would be with a brushless motor though.

Yes you will get lots more speed with higher voltage (not higher milliamps). 50% more votlage should result in almost 50% more speed. Give it a shot with a 3-cell lipo if the ESC can handle that. If not, then you need a different motor with a higher KV rating...

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Wheel speed is quite low and is actually faster in reverse for some reason.

If its a sensorLESS motor / ESC, try reversing the throttle channel on your radio, and swapping 2 of the 3 motor wires, and it should run faster foward than reverse..

(In a sensorless system, swapping 2 of the 3 motor wires will reverse the direction of your motor.... DO NOT do this to a sensored system, they need to be reversed in the ESC's software..)

Cheers

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If its a sensorLESS motor / ESC, try reversing the throttle channel on your radio, and swapping 2 of the 3 motor wires, and it should run faster foward than reverse..

(In a sensorless system, swapping 2 of the 3 motor wires will reverse the direction of your motor.... DO NOT do this to a sensored system, they need to be reversed in the ESC's software..)

Cheers

It is indeed a sensorless system. I swapped 2 of the three wires and the result is the same. I imagine if I switch the reverse/forward on the TX then it will do the same but go in reverse when I press forward etc?????

Mark

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