Where to find info on lipo conversion

[markb_s1 6]

Hi folks.

Having recently reignited my interest in RC after 30+ years away from it I keep reading abotu how lipo power is great because the batteries are lighter, last better and deliver a more constant current.

My question is, where can I find info on exactly what I need to buy/do to convert my currently bog standard neo fighter to lipo?

 

it has the standard brushed torque tuned motor and i'm currently running the tamiya ESC with a 6 cell 2300 nimh battery pack.

 

thanks for any advice!

[ploots 185]

Hi I'm fairly new to lipo myself but if you look in ALL THINGS ELECTRIC section on page 4 someone has asked a similar question and there's some very good links and info on there,I hope that is of some use for you 👍

[Problemchild 2149]

Lipo needs not too much conversion 

thinks like the standard ESC can manage 

however it’s the looking after them that’s the hard bit 

you can’t store them at full or empty 

they can catch fire so you need to keep them inside something 

charging needs a special charger and a specific power supply (add will say you need to get a power supply)

you need to programme the charger for a specific rate etc 

connectors on LiPo will not be Tamiya so some soldering or (not recommended) but I use adaptors 

but the benefits are well worth it 

especially if you get say a £30 goolRC motor and ESC combo 

the cars a b fast and fun

 

 JJ

[mud4fun 1696]

Why do you need LiPo?

I ask because if it is extra run time then it would be far cheaper and more practical to simply buy a 3300-3600mah NiMh which can be charged on your existing charger, doesn't need special chargers and doesn't need to be stored with a specific storage charge. It can be stored fully charged and ready for use.

On a relatively modest Torque tuned motor and stock gearing there will be negligible gains from going 2S. You will get a slightly quicker top speed but in all honestly it won't be that great. You could gain far superior performance gains and alot longer run times by getting a better motor, a change in gearing and using a good high capacity NiMh. All far less hassle than going LiPo!

[markb_s1 6]

Thanks for the advice folks. Some food for thought there. I thought the reduced weight might give better performance as well, but if they're that much hassle maybe not worth the effort!

[mud4fun 1696]

10 minutes ago, markb_s1 said:

Thanks for the advice folks. Some food for thought there. I thought the reduced weight might give better performance as well, but if they're that much hassle maybe not worth the effort!

A 5000mah LiPo will be about 50g+ heavier than a 3300mah 7.2v NiMh (as much as 100g depending on brand). So yes, there is a weight saving but to be honest you can get that same saving from swapping to a lighter steering servo, smaller ESC, smaller receiver or titanium screws. So basically if cost is more of a factor than performance then I'd choose a high capacity NiMh. If money is no object then sure, go for LiPo but then you potentially need a new charger, a LiPo charging case, a fireproof storage box and you have to make sure you always charge them to a storage charge before packing them away. This means that if you just fancy a quick run you have to charge them before use back up to the normal full charge. With a NiMh you can store them fully charged and within a few weeks you can grab a pack, drop it in the car and go. Depends on the car but IMHO the weight saving is minimal, it can make a difference on certain cars, especially transverse battery buggies but in all honesty the cost and hassle involved negates that minor advantage. For us, we like long run times as that gives us more time to have fun. A big capacity NiMh is cheap and gives equally long run times to most reasonably priced LiPos 

The only buggy we have that really gained noticable improvements from using a lightweight LiPo was my Thundershot HOWEVER that was going from a VERY heavy 8.4v Sanyo NiCd to a lightweight Absima 4000mah LiPo, some 120g saving!!!

[87lc2 2659]

If you just have the one car with a brushed motor and not planning on getting more or putting a brushless system in it NiMh is fine.  However, if you plan to upgrade power in the future or you think you'll be buying more models just bite the bullet and go with Lipo now.  They're inexpensive nowadays as are the chargers and they do perform better.  The only special thing you need to do with them is keep them somewhere safe (I use cheap ammo cans that can be bought anywhere), not much special care needed.  Of course you need to look after the cells, but that's not a huge deal.  I have been using exclusively Lipo for 5-6 years now and have never had an issue, and I wouldnt say I'm diligent about taking care of them either.  Don't be scared off by some of the horror stories, if you're looking to get back into RC and you think you'll be buying more cars/upgrading just go for it.  

[Frog Jumper 3656]

I just switched to lipo about 8 months ago. I don’t treat them any differently than the nimh I own. I’ve even been lazy about storage charging bc I charge (outdoors) the lipo up about every week for test runs.  Probably not best practice but lipo has turned out not to as scary as the stories make it out to be.

The only change I had to make is switching out the Tamiya plugs on my ESCs to XT60 connectors. One night with some beers and a soldering iron and it was done.

The charger I bought when I first got back into RC does all kinds of batteries so I’m glad I made the investment early on.

Terry

[Wooders28 4718]

The best way, is with a 1060 esc.

Yes you can get wee alarms that plug into the balance lead, but swapping to a 1060 means you have the option of 3s, and / or hotter motors (it'll run down to a 10t on 2s) if the mood takes you.

 

[markb_s1 6]

thanks for all the useful advice, people.

[Wooders28 4718]

1 hour ago, markb_s1 said:

thanks for all the useful advice, people.

There's the actual Lipo care you need to look into.

A decent charger ,looking at £40. The Imax B6 used to be the goto, but as all good things, cloned to death. There's plenty of LCD chargers out there though.

Charge bags are a must, Lipos are at their most grumpy when getting charged.

All the info you even need is here:- 

 

https://rogershobbycenter.com/lipoguide/

[Problemchild 2149]

A LiPo and a £30 brushless gool RC combo transforms a car 

@Frog Jumper I’m a bit like you. Sometimes I remember to put them into storage charge and I just use a LiPo alarm 

they aren’t overly expensive for something like a fleureon 3s so not overly worried 

I did spank one against a pole in my quad though and put a dent it it so I discharged it fully and binned it as when I use them in my car, I don’t want it to go up in smoke 

JJ

[Carmine A 2046]

I'm SURE most of the Lipo Myths have been Hyped through the Roof!!! But you shouldn't ignore them either. Like moving into anything with vastly more power (Cars, Power Tools, Wives!), REQUIRES at least a healthy Respect.

I've only been into Lipos for about 3 years... The Storage and Power Delivery are quite different than NiMH. Many People don't even notice (simply because of HOW they use them). 

A fully Charged 3500 MAh, 7.2v NiMH starts out between 7.25 and 7.4 volts. By the time it's 80% discharged, it's only putting out about 5-6 volts (depending on type/brand/total capacity)... 

A "comparable" 3500 MAh, 7.4v Lipo (2S), starts at around 7.55 and 7.9 volts. By the time IT'S 80% through its cycle, it's still putting out between 7.25 and 7.45 volts!!  Lipos ALWAYS have more output capacity than any conventional type. And going up in "C Rating" (which actually means Rate of Amperage and Voltage Discharge), increases those figures even more! 

150C Racing Lipos retain almost 90% of its rated output by the end of the Run!!  😲  20C and 35C Lipos do not. 

Of course an increase in C Rating also increases volatility, exponentially! They ARE potentially DANGEROUS if not handled (charged/discharged/storage charged) CAREFULLY.  Lower C Rating Batteries tend to be more forgiving. 

SIDE NOTE: MOST YouTubers who have made "exploding Lipo" Videos, have mostly used 100-150C Lipos - charged in the NiMH SETTING. Some even poked HOLES in them for effect!!! 

Puncturing any Lipo makes them EXTREMELY Volatile, guaranteed to shoot Flames, and make clickbait Videos. 

In your case.... Try Lipo if you want! Keep the C Rating UNDER 50C (this MUST be prominently displayed on every reputable Battery).  Get only Hard Case Lipos (that's the Hard Plastic Case, instead of the more common soft, Cellophane case Lipos). It's your best line of defence against the occasional HARD impacts, that Buggies are prone to!! 

Bin the Tamiya ESC - as it has NO Lipo Cutoff or any protection. Hobbywing, GoolRC, Carson, Redcat and several others sell good, low cost ESCs WITH proper Lipo Cutoff. 

And a Lipo Cutoff is a special internal circuitry that measures the voltage of EACH CELL, not just the total Battery output. If ANY of the Cells falls below a specified Voltage (default is 3.6-3.7 volts per Cell), it will SHUT DOWN the ESC, while leaving full steering control for safety.

{I usually increase Lipo Cutoff to 3.9V... Slightly shorter Runtimes, but considerably longer Battery Life!} I haven't had to replace ANY of the Lipos that I bought 3 years ago!! 

You can and should get a good Lipo Charger. They will also Charge NiMH (and LiFe, LiHt, and some even Charge Wet Lead-Acid Batteries - like what's in your CAR or maybe Golf Cart) Decent ones can be had for between $25-50. You DON'T need the best up front. You just need one with a dedicated Balance Charge feature. That also plugs into the smaller Balance Lead when Charging, measuring each Cell to ensure even Charging.  ONE bad or discharged Cell can also be dangerous! 

It's like anything else in Life. Take reasonable and Common Sense precautions, and you'll be just fine!! 😊

[markb_s1 6]

thanks.Very helpful.

[markb_s1 6]

sorry to resurrect an old thread... i think i'll stick to the NiMh batteries for now.. can anyone tell me what the maximum capacity NiMh battery I can use with my srt up is? or is it more a matter of what my charger will charge and what will physically fit in the cars?

 

Thanks.

[Frog Jumper 3656]

2 minutes ago, markb_s1 said:

sorry to resurrect an old thread... i think i'll stick to the NiMh batteries for now.. can anyone tell me what the maximum capacity NiMh battery I can use with my srt up is? or is it more a matter of what my charger will charge and what will physically fit in the cars?

 

Thanks.

It will be a matter of what fits in your car. Larger capacity equals larger battery. When I used Nimh batteries, the onyx 3300 would fit my GH but the 5000 would not. 

[Willy iine 18804]

NiMH amp capacity is determined by the cell chemistry,  not the physical size of the Sub-C cells.  You can make your own packs with 1500mAh or 5000mAh cells.. does not change the physical size.  

Maybe I'm not understanding the question.. ?

[simalarion 2194]

Any 4wd should have Lipo as the terrible fast volt dropp in Nimh will not give enough power to 4wd differencial and gears, on the very heavy Monstertrucks with 2 silvercans you should even go for 3s.

As for using Lipo its no problem as long as you Charge same day as driving and discharge/charge back to Storagevolt setting(ca 50% of battery capacity or mah) when done. I but mine in separate smal BatSafe container for storage, why not the big one?, because im thinking if one battery catch fire i dont want all lipo in same box.

Lipos have grown on me and i quite like the litle ritual setting them in storage mode etc. And remember if you use standard ESC to buy a Lipo Alarm from Ali that tells you when the volt is low and time for you to stop driving.

As for lighter RC cars Nimh will cind off work but that depend on how «seirious» you get, you stil have that faster Volt dropp and after getting used to Lipo i will not return to Nimh

 

[Wooders28 4718]

21 hours ago, simalarion said:

after getting used to Lipo i will not return to Nimh

I fooled myself saying I'd go back to Nimh,  but it was like going back to CRT TV after getting used to 4k.

I found, an almost at cut off voltage lipo,  is around the same as a charged Nimh.

[Willy iine 18804]

1 hour ago, Wooders28 said:

I fooled myself saying I'd go back to Nimh,  but it was like going back to CRT TV after getting used to 4k.

 

 

NiMH has its space.   I like them.  I have LiPo's for the same car applications in storage since 2016-2017.  I like LiPo enough that I haven't toss them thinking I would use them again some day..  I like the power, I just don't like the hassle.

[markb_s1 6]

not having ever used lipo... i reckon i will stick with the old skool batteries.. just because the quicker performance drain gives my aged reflexes a fighting chance!

 

 

[El Gecko 1343]

On 11/7/2021 at 9:04 AM, markb_s1 said:

sorry to resurrect an old thread... i think i'll stick to the NiMh batteries for now.. can anyone tell me what the maximum capacity NiMh battery I can use with my srt up is? or is it more a matter of what my charger will charge and what will physically fit in the cars?

 

Thanks.

Max capacity of the NiMH will be determined by how much you're willing to spend. The cheapo generic 5000mAH NiMHs have been fine for my usage (mostly bashing and a bit of postal racing) but Tenergy or Venom or other better-known brands will have higher quality connectors and possibly higher discharge rates due to using better cells. Some of the name brand packs are also just repackaged generic cells, so it's hard to tell which are the "good ones".

On 11/7/2021 at 9:07 AM, Frog Jumper said:

It will be a matter of what fits in your car. Larger capacity equals larger battery. When I used Nimh batteries, the onyx 3300 would fit my GH but the 5000 would not. 

This seems to be the case with only certain 5000 NiMHs. I have a decade-old Traxxas 5000 with cells that are a few mms longer than normal, and it's a tough fit in any chassis. The new Chinese generic 5000s I got are the exact same size as my Gens Ace 3000 and all my old NiCds, so there's no issues with fitment.

[Frog Jumper 3656]

50 minutes ago, El Gecko said:

Max capacity of the NiMH will be determined by how much you're willing to spend. The cheapo generic 5000mAH NiMHs have been fine for my usage (mostly bashing and a bit of postal racing) but Tenergy or Venom or other better-known brands will have higher quality connectors and possibly higher discharge rates due to using better cells. Some of the name brand packs are also just repackaged generic cells, so it's hard to tell which are the "good ones".

This seems to be the case with only certain 5000 NiMHs. I have a decade-old Traxxas 5000 with cells that are a few mms longer than normal, and it's a tough fit in any chassis. The new Chinese generic 5000s I got are the exact same size as my Gens Ace 3000 and all my old NiCds, so there's no issues with fitment.

That’s for the correction/update!