Originally Posted by
dingobattler
We should be moving towards Li-ion for RC tanks, since weight and speed are not a factors at all.
I don't see the issue with sticking with a 5000mah nimh battery pack either. It pretty much lasts an hour for a 5kg tank at max volume with lights, which is more than anyone needs. If you go longer, then get 2 packs and charge one with a fast charger will using the other. Certainly cheaper than using lipos with a good charger, LVCs, and all the other tools you need to make it run safely.
All batteries will burn, but lipos are by far, the most temperamental and destructive.Can't take hard knocks, needs constant supervision while charging, need LVCs, charging bags (doesn't work - see youtube), and other nonsense.
Charging bags don't work either. The only way to reasonably store them is in an ammo box, lid off with a bad of sand on top, and even then, there's still smoke damage. Every other way is just asking for a fire.
https://www.youtube.com/watch?v=CnNId0mDnBo&t=
Burning down a $1k tank aside, property damage is far more concerning. I'm a homeowner, and no lipos will ever be passing through my doors.
I've been pushing the NIMHs over Lipos for tanks for a while and I totally agree with not NEEDING them in the tanks, but at some point we will have to swap over to a new battery. They are starting to get in the 20lb range soon for the modern tanks, bigger motors, and more features so it only makes sense
in the future. Many things have changed in lipo tech over the years. If you haven't looked into LIFE batteries then check those out, they are a ton safer than even li-ion batteries. While the discharge isn't as high as other lithium packs that is ok for our application since the current demand is pretty low.
Also the old ammo can method is a bit outdated at this time. There is a product called the Bat-Safe which is amazing and works pretty darn good. There is a video on YT of it containing x15 4s 1300mAh packs with minimal effect. There are also filters to help tone down some of the fumes/particulates. Even after the 15 batteries went up (in the mid ranged box, not even the large one) they still came up to the box and opened it a min or two later due to the dual walled container with insulation. Don't get me wrong, there is going to still be a lot of smoke, but almost remember that video linked above is a LOT of battery in those tests. That test is pretty skewed actually, when I ran the numbers I came up with this:
Test 1: 191.52W
Test 2: 403.2W
Test 3: 1394.24W (this was the massive fire)
Test 4: 151.2W shown plus "various packs"
Test 5: 201.6W shown plus "various packs"
Test 6: 215.04Wh shown plus "various packs"
The thing to remember is those were some very big packs. A lot of those are 4-6S lipo packs and double or quadruple the voltage we use in the tanks. A typical 6s NIMH pack is around 15-18ish on a stock 2000mAh pack. A 2s 5000mAh pack would only be 42Wh. That was a lot of battery they put in there and none of them were the same packs or amount of watt hours to make a good comparison. While I am a very big safety guy especially when it comes to lipo I do almost exclusively use them.