B4 and Saddle pack lipos
 

I am thinking of getting some 4800 lipo saddle packs for my D4 but i am not sure if they will fit a B4 can anyone help please

As long as each saddle is the same size as a subc saddle then you should be able to put them together so that the overall length is equal to a stick pack.

Might be too tall to go under the B4 brace!!! Best check the dimensions.

see this vid... yes they did the stupidest thing but could this happen if you accidentally charged a lipo on a nimh setting??

http://www.youtube.com/watch?v=KpUXuEg3fNE

Have you personally experienced a Lipo battery fail in such a spectacular way under normal RC conditions? Or do you just not like Lipo and want to scare people? Either way the end of your post was totally pointless, under no circumstances should/would anyone plug a lipo of any kind to a wall socket!

Personally I have never seen a Lipo fail under normal conditions, granted I have not been around them very long either tho. I have seen at least 2 NiMH cells go bang in a fairly major way under what I would call normal use (not BRCA Recommended tho), luckily there were no injuries.

Regarding saddle Lipo in a B4 I would do as Roger suggested and check the dimensions as can be found on www.trakpower.com

i dont hate them, i was told about the video on youtube today. i havn't seen any NiMh blow up yet, even 2 chargers on a 5cell pack at well over 10amps. i know lipo's the future but we cant get too hyped about them if we're not allowed to use them at 1/10th OFF ROAD NATIONALS.

i had a saddle pack in 1 hand and a b4 in the other about 4 hours ago and it dont fit, sorry. its too tall, they'll fit in a b44/bj4/d4 tho.

plugging a pack into a wall is stupid but the pack could do this if you accidentally charge it on your nimh setting

they fit the d4 but you need to lift the rear top deck by 3mm, and extend the battery posts
they will fit a b4 if your creative with the brace and how it fits
the 3200 saddle will fit in both with no mods
1/ that aint a trakpower pack
2/ thats abused to make it go bang
3/ they dont got bang if you use them in the manufatures guide lines

you can use them they are allowed to be used under the BRCA at touring nationals and any other meeting unless regionals nationals dont allow em, ie the schumacher winter serries thats just gone


and again they do fit a b4 if you modify the battery strap, tho the 3200 saddles will fit in no modification in both
the 4900 stick is designed for the b4

think its fair to say your making some unfounded claims!! :thumbdown:

If you plug your PC's mouse on a wall socket, I'm sure it will go bang too ! But does it means that we need to ban mouses ?

Let's ban wall sockets !

Cheers guys think i will get some 3200 so theres no messing around

Mrk, I'm not asking for any other reason than curiousity but..........

what advantage does the 3200 lipo offer me over a NiMh of 4200+ mAh???

I am tempted to get a Lipo to use for practice sessions but it would need to give me an advantage over the NiMh cells I have (4500s by the weekend hopefully) and fit in the RB5.

You've always been helpful in the past with Lipo info so please don't let me down now!!! :D

I hope you don't have any screw drivers in your toolbox as they can be lethal if you accidently stab yourself with them :woot:

Or travel to race meetings in a car as there deadly if you hit a wall at 100mph :woot:

Or we could all use a bit of common sense :thumbsup:

For equal capacity Lipo normally offer longer run times. A 3200 Lipo would probably offer the same or slightly longer run times than 4200 NiMH.

The 3200, 4900 and 5400 TrakPower packs fit straight into a B4/CR/B4 so I would assume they will fit into a RB5 as well. Looking at the dimension's on the TrakPower site the 3200 is lower than both the 4900/5400 so it may need some extra spacing.

The advantages of the Lipo are that they require very little maintenance and up keep compared to NiMH from my experience. This is great for a battery that will only be used for practice sessions. They can also be charged days/weeks before an event and still hold there charge.

It also means that your NiMH's will be kept in top condition for the races that count.

Cockrill, thanks for the response. I am confussed about your comment that you get more run time mAh - mAh with Lipo ..... anybody explain how that works.

Pardon my ignorance but I know very little about this cell technology.

lipo b4
 

have you thought about getting the trackpower 4900 they fit perfectly in my b4 and give great run times, as for charging them I use a much more ac/dc silent charger about £75 from dinball/ebay or £125 in gb. also use a charging pouch about £10. My b4 get plenty of abuse and the lipo,s are fine. I suppose any battery would explode if connected directly to the mains. Trakpower 4900 are Brca approved to ease your worries

Dont know exactly how they do it but you do get 2 full 5 min runs plus more from the 4900 packs (Ive had about 20 mins including pre race testing) They wiegh a lot less than nihm so have less work to do in my expierience they leave my nihm 4500 for dust. You just charge them up and as they have a very low self discharging rate you can charge them up weeks in adavnce and have no problems. A big plus is they do not need discharging, you just run them and recharge. If you do get them you must never let them drop below 6.2v. You can get the novak smart stop to do this simply connect to reciever and battery wires and the car will stop and a blue light lights up to let you know you have reached the lowest safety voltage for your lipo pack or your esc may have lipo protection built in.

I don't know the science behind it, but I *think* Lipo have a lot lower IR, therefore they are capable of producing more Amps for a given voltage. I'm sure Mark C will be able to tell us exactly why it happens.

I'd have thought the nimh getting hot to the touch whilst being used was itself using up energy?

Why do lipo`s become "unstable" once they drop below a certain voltage?

Surely when they are manufactured they dont start there life at 6V+??


Just curious, not having a go:)

sorry for the delay, wanted to get this right so asked trakpower direct

3200 seems like 4200 due to the way the cell works, because they sustain a higher voltage under load, (the science bit) the watt hours are higher than a nimh pack, this in turn reduces amps for the same output giving the cell a better ability to deliver thier capacity more efficiently, hence the packs dont get hot loosing efficincey and the 3200 lasts longer in run time


next

low voltage causes a chemical reaction in the pack this turns to heat, gases are created and fire can occur. this occurs under 3volts per cell
i presume when the packs are made there is a residual voltage in them from the chemistry
capacity is measured on a lipo FROM the cell being at 3 volts so a cell is at 3 volts, its charged then that will give you its capacity
by discgharging below this at high current draw will result in swollen/damaged packs. if you have left the pack plugged in over night and the draw is only low, the cell can still be damaged, but it is possible in some cases to recover the pack, i can unoficially tell you how when i have more time, its not the done thing but it can be done under close scruitiny

hope that helps a bit, any more questions and ill do my best to get you correct answers!