Li.ion to nmh

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Rad_Schuhart
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Re: Li-ion 7.4 to Nimh 7.2 in HL PZ 3

Post by Rad_Schuhart »

Black Knight wrote:
Rad_Schuhart wrote: li ion batteries are much better than nimhs.

And nobody should use the tamiya conector, thats junk. You can use XT60 or T Deans instead.
Why?
Nimhs self discharge (even a 20% in the first 24 hours!), just for that I would discard them. It also takes more energy to load them, wasted in heat.
4 li ion have more amps than 6s nims, in a bit less space, and less weight. with 4 good quality nimhs you can have 7.000 amps, with lets me drive my tanks for more than 5 hours non stop.

And regarding the tamiya connectors, those are bulky, unreliable, and even dangerous (risk of fire) if you draw too many amps. I use XT60
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Re: Li.ion to nmh

Post by Ragnar »

Ok now this is the type of information that’s really useful to noobs like myself! :thumbup:
Having just purchased a Taigen Tiger 1 metal edition with a Nimh in it thought it should of been a bit better quality battery than what came in my Henglong P3 .maybe I was mistaken huh.
Last edited by Ragnar on Wed Aug 07, 2019 3:21 pm, edited 1 time in total.
But it’s a dry heat!
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Re: Li.ion to nmh

Post by jarndice »

In the UK if you go to -------
www.component-shop.co.uk
When ordering a battery they will fit a non Tamiya connector at no extra charge :thumbup:
I think I am about to upset someone :haha:
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Rad_Schuhart
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Re: Li.ion to nmh

Post by Rad_Schuhart »

Ragnar wrote:Ok now this is the type of information that’s really useful to noobs like myself! :thumbup:
Having just purchased a Taigen Tiger 1 metal edition with a Nimh in it thought it should of been a bit better quality battery than what came in my Henglong P3 .maybe I was mistaken huh.
Well, the quality of the cell is also very important, so you never know what is inside of the heng longs.

I started in the hobby with lipos, but after some lipos puffing, and tons of people in forums and in youtube with the house in flames I discarded them.
Then I got high quality nimhs, and are fine, really they are, but takes long to charge, and the self discharge pisses me. I hate to pay for nothing. (I will sell them, those are almost brand new)
Then I discovered the li-ion, that are used in electric scooters, all kinds of machinery, even tesla cars... So I thought I could not go wrong with them, so I did my own packages with good quality li-ions and I am very happy.

This is just my experience, dont take it like a bible.
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Son of a gun-ner
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Re: Li.ion to nmh

Post by Son of a gun-ner »

Not being such a skin flint as Rad, I'm quite happy using high amp hour NiMH batteries. And Tamiya connectors are ok, so long as you make sure they make a good connection each time. But, Rad is right about changing them for better ones.
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Re: Li.ion to nmh

Post by Ragnar »

Well being a retired man of leisure myself charge time is not a big deal,and I kinda like the Tamiya style connector with the single lead, to several styles of the double leads on the Li-ion battery’s for sale which confuses me on looking at their pictures on the web


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Re: Li.ion to nmh

Post by Son of a gun-ner »

The extra pair of wires is for the charger to balance the charging across the individual cells of the lithium batteries.

With Tamiya connectors, the female tube part can end up opening up. But the worse thing is that when you connect them, the metal connector parts can push in so that you don't get a proper connection. This catches out many who are new to RC and those connectors. And they can't figure out why their tanks etc don't work.
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Re: Li.ion to nmh

Post by General Jumbo01 »

When l was racing all my cell packs were hard cased 2 cell Lipos, 6000mah min and all very high C ratings. These gave me ample lightweight power to race a 5 minute heat and a massive discharge rate that allowed me use low turn sensored brushless motors. I wouldn't dream of using anything so crude as a Tamiya plug or even a deans - the massive amps used would melt them along with any stock solder. I used silver solder and gold plated 5mm barrels.

HOWEVER, we are not racing our tanks or using big high draw motors etc so Tamiya plugs and NiHMs are fine for our purposes (or deans if you enjoy the struggle!) . As for charging times, pay for decent packs with a high C rating and you can charge at much higher charge rates, providing you buy a decent charger that gives you all the options. You don't need to be rich, just savvy!
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Re: Li.ion to nmh

Post by Max-U52 »

Larry, do you have Skype? Or a laptop or smartphone? If we can get together on Skype I can show you all this stuff, from Chargers to xt60 to xt90 connectors and pretty much everything else you need to know. Remember, I advised that you get the good charger because it will charge all different types of batteries. A lot of times it seems like you're saving money to buy the cheap charger but if it only charges one type of battery and you have to buy a different charger for every type of battery you have you're really not saving any money. It's best to just get the good charger to start with.

Let me know about the Skype thing. If you don't already have it, all you need is a laptop or smartphone and you can download it for free and then you can make video calls, as well as international text for free.
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Re: Li.ion to nmh

Post by Black Knight »

Some great information chaps! It's always good to hear WHY an item is "crap" and why something shouldn't be used.

I personally run a 3s, 5000mah 50c Lipo (Gens Ace) because I have a DKLM metal hull and running gear on my Challenger 2 as well as the DKLM PDSGB. The tank weighs in at just over 1st (around 7kg) and I figured that I would need a little extra oomph if I wanted to get anywhere near close to a realistic scale speed. As you can imagine, the system draws a fairly high current so I use XT90 connectors because they seem to be nice and big (plenty of contact area) and secure. When I start my re-build I will be incorperating some computer fans in a bid to keep the temperatures down on the board and the motors (so far I haven't experienced any heat from the battery!)

Definitely get a decent charger regardless of what battery you get - I threw away 2 quite expensive batteries because they wouldn't charg, then bought my Lipo and a decent charger. When I had the same problem (battery not charging) with my boy's tank I tried a decent charger instead and all was fine!
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