TOPIC:

Is anyone out there actually using Li-Po's with vintage Tamiya with good stories to tell on how it's revolutionised their running?

That's nice, JR's missing me! (You cunning linguist!)

NiCds are a personal preference - Lipos have more instantaneous current to give & longer run times, Nimh have higher capacities & supposedly longer run times, but both have given me less than they promise on the packet, I've yet to find one of either that impresses me.

Ok NiCds don't give great run times (I get around 4 minutes with modified motors, 10 minutes with standard cans if I'm lucky), but they survive being made "warm" with aggressive driving & fast charging, (I've never got more than 1x use out of a Nimh if it gets warm, including power tool batteries) & 10-30 year-old packs I own still work well (Lipos I've had last only a few months if I haven't used them much).
NiCds do suffer from "memory effect", but this can be avoided by flattening them completely when you use them, & by forcing them to take a full charge - delta-peak chargers tend to make the memory effect worse in my experience.
High capacity NiCds I've had have all been pants - I tend to stick to 1400mAh or less, & Proper Tamiya ones seem to be best (They've outlasted my Sanyo race packs from the 80s anyway).

Interesting story - RS components dropped NiCd power tool packs in favour of Nimh ones a few years back, & now they're offering NiCds again as "Higher power, heavy duty" upgrade packs to replace the "Basic, get you by" Nimh ones that come with the tools.

Can't say I've ever had a NiCd try to set fire to my kitchen, or destroy the model it was in, which is more than can be said for Lipos. They certainly don't do that when they're not plugged in to anything (Again, more than can be said for Lipos!).
Lithium should be saved for making bombs, not for powering consumer gadgets in my opinion




I did a couple of Thunder dragon/shot restos a while back - have a look, it might be helpful (Should be a link at the bottom of my posts)

Hi Eddrick

Thanks very much for this reply - you've managed to put me right off Li-Po's in one fell swoop!

I take it that heli-pic is yours and the unfortunate result of a Li-Po battery spontaneously combusting whilst in or just after use?

Now, I don't know what to do! I'd be happy if I just managed to double my run-times instead of going for the 40+ mins - when you run for 10 mins, it just seems to be over all too quickly.... When you're having fun, you want it to last at least a bit longer!!

Anyone else out there with good long-term stories to tell about Li-Po's running in their vintage Tamiya?

Don't let me put you off Lipos, I just personally haven't had much luck with them, whereas other people swear by them. Same story for Nimh. Probably a good plan to try for yourself to get your own idea about them. Just be careful to buy good quality ones, that's all I'll say (Heli battery was a cheap replacement).

The heli battery was just sitting there doing nothing - I charged it for a brief time, then unplugged it as I had to go out. I came home about an hour later, which fortunately was when it decided to self-destruct. Might've been in trouble if it had decided to do that in the loft...

Trick to long run times is get yourself multiple batteries & a fast charger. Charge em all up & go play.
Yep, 4-10 mins isn't long enough, but I'm usually getting bored by the fourth pack (30-40 mins)

I never had any matter with LIPO's on my traxxas slash but I am a little affraid now. The interest for me is to use with brushless motors and need other type of connectors and not original poor tamiya ones

eddrick wrote:

Don't let me put you off Lipos.

Trick to long run times is get yourself multiple batteries & a fast charger. Charge em all up & go play, but I'm usually getting bored by the fourth pack (30-40 mins)

Too late!

Trouble is, that I had intended to buy four of these Li-Po packs, as I have three children who all want to play too! It would be fine if it was just to charge 4x Ni-Cd's and go play - but I can't be charging 16 for all of them too!

Would still love to hear from anyone using this forum who's running a Li-Po battery with their vintage Tamiya - would really like to hear their experiences, and assuming so, what kit they're actually using....

Well, like Jonny said, get hard-case Lipos, there's less chance of them going critical-mass through physical damage, & as long as you stick to well-known/quality makes, they should be ok.
After all, lithium batteries have found their way into all kinds of consumer goods (Phones, laptops, toys, cameras, watches etc) & that wouldn't happen if they weren't safe... it's just the naff ones that look identical to the good ones that you've gotta watch.

I here what you're saying about needing longer run times to go play with the kids. How old/skilled are they? - lower performance motors can be just as much fun & give longer run times, depending on where you're running the cars.
Say you were running on the beach, would you really notice the minor drop in performance by using a 35 turn motor, or would you just be happy at the 20+ minutes run time you got from it?
Have you considered crawlers/scalers rather than race cars? - I personally enjoy some skillful slow negotiation of awkward obstacles as much as flat-out sliding around (Cheaper on tyres too)

eddrick wrote:

Well, like Jonny said, get hard-case Lipos, there's less chance of them going critical-mass through physical damage, & as long as you stick to well-known/quality makes, they should be ok.
After all, lithium batteries have found their way into all kinds of consumer goods (Phones, laptops, toys, cameras, watches etc) & that wouldn't happen if they weren't safe... it's just the naff ones that look identical to the good ones that you've gotta watch.

I here what you're saying about needing longer run times to go play with the kids. How old/skilled are they? - lower performance motors can be just as much fun & give longer run times, depending on where you're running the cars.
Say you were running on the beach, would you really notice the minor drop in performance by using a 35 turn motor, or would you just be happy at the 20+ minutes run time you got from it?
Have you considered crawlers/scalers rather than race cars? - I personally enjoy some skillful slow negotiation of awkward obstacles as much as flat-out sliding around (Cheaper on tyres too)

It's not the motors (not that I get anywhere near 20 mins from a standard silver can!) - I tend to find that they all run the same (circa 10 mins) whether it's a silver can or a Technigold, so presume it's down to me giving some decent welly no matter what motor I'm running at the time.

Crawlers are great, but very expensive. I've been keeping my eye our for a CC-01 based crawler for ages, but they go for way too much, and too much for the kids to have one of them! I'll let them loose with my old monster buggies for now, and they love those.

I'd already decided in my mind that I'd stick to a Turnigy hard-cased battery to kick off with - probably a 5000mah or so, but would still love to hear from ANYONE that is actually running Li-Po with their vintage Tamiya and can share their experiences? (and also the kit that they are using?)

I accept your point about Lithium making it into most retail consumer goods, but this is Lithium-Ion and not Lithium-Polymer. You're right, I've never heard of someone's mobile spontaneously combusting, but this is for the same reason - it's a different chemical mix and much more stable. Lithium-Polymer seems to be a very different beast altogether, and something that at least some manufacturer's are getting hopelessly wrong.

rjsdavis wrote:

... would still love to hear from ANYONE that is actually running Li-Po with their vintage Tamiya and can share their experiences? (and also the kit that they are using?)...

Can't help but feel I've already posted all of this, but here goes:

I've been using a mixture of Turnigy 2200mAh 1S 20C (bought as single cells; two + wiring makes a 2200mah 2S 20C Lipo) fitted into 7.2v & 6c hard cases (see article here ; and Turnigy 1600mAh 2S 30C Lipos (see here also fitted into repurposed old skool 7.2v nicad cases ... no-one's died, there have been no explosions or fires

I use them in anything they'll fit in - Holiday Buggy/Sand Rover, Frog (& other ORV based chassis), Wild Willy, SRB chassis, etc etc ... but not in more modern chassis which will only take stick packs. I haven't attempted to scientifically measure the Performance increase over 7.2v nicad or NiMH, but I'd put it at somewhere between 15 and 30 percent, especially on acceleration.

I use warning beepers on the balance lead as none of my ESCs have Lipo support, and obviously MSCs (in the few cars that still have them fitted) don't either.

I can't directly compare them but my feeling is that run times are longer too (30%?) than you'd get from a nicad or NiMH of the same capacity - due to not needing to use the throttle quite as hard to get the same result.

A (genuine) IMAX B6 (powered by an old PC PSU) does charging duties.

Have you ever done a controlled discharge of your NiCds to see how much juice is actually in them?
I can usually drive 30-45 minutes on a 2Ah pack myself, 10 minutes just sounds like they're not charged right.
Feeding 200mA for 10 hours (for example) doesn't at all mean they've been charged up to 2Ah.