Life / lifepo4 battery pack options

[gba888 0]

I'm looking to get a new charger and a battery pack or two. I've decided that I'm going to go from nimh to life/lifepo4 batteries. I have no interest whatsoever in lipo due to the potential dangers. I do not race, only "bash" and lipo is simply not an option for my purposes.

The main cars I run are: grasshopper, boomerang, vintage rc10 and an rc10 b4.1. I understand that I need the 6.6v versions of the life packs, but can't find clear options of which packs are available that will *fit* into the space that the nimh 7.2v packs occupy.

Can an expert please post some links to packs that will fit into these cars without much modification? The boomerang and the grasshopper have pretty size specific battery compartments. The vintage rc10 is probably the most flexible in that area, though. I just want to get a pack or 2 that will fit in all the cars I mention above. Thanks for any help!

[TongueTied 56]

+1

I'm in a similar situation and am really interested in LiFePO4 options.

[TA-Mark 195]

This is what Tamiya has on offer. Tamiya.com. Fitment.

These packs require a specific Li-FE charger. Most other chargers that list Li-ION are only for Li-Po with a charging range of 6.0v to 8.4v (too high for Li-FE).

Li-FE packs require balancing the same as Li-Po.

You will notice a reduction in model speed when using 6.6v versus 7.2v/7.4v. The packs are only 2200mAh, so about half the runtime at a reduced speed when compared to a 4000mAh Li-Po hard case which fits in the same shape battery holders. See this thread for suitable Li-Po packs.

The ESC must have a low voltage cutoff suitable for Li-FE packs, which is 5.0v (TEU-104BK). ESCs with programmable cutoffs are suitable, where as ESCs with a Li-Po 6.0v-6.2v cutoff will not run for long before the ESC shuts the motor off.

In reality these Li-FE packs are no safer to use than hard case Li-Po packs or even Ni-MH packs. Mistreat any of them and they will all go up in smoke. To date I've only ever had Ni-MH go bang (like a grenade in my face). I've been using hard case Li-Po and A123 Li-FE cells for the last few years without issue, although I'm using 3S Li-FE (9.9v) in a custom chassis and in a boat.

[gba888 0]

This is what Tamiya has on offer. Tamiya.com. Fitment.

These packs require a specific Li-FE charger. Most other chargers that list Li-ION are only for Li-Po with a charging range of 6.0v to 8.4v (too high for Li-FE).

Li-FE packs require balancing the same as Li-Po.

You will notice a reduction in model speed when using 6.6v versus 7.2v/7.4v. The packs are only 2200mAh, so about half the runtime at a reduced speed when compared to a 4000mAh Li-Po hard case which fits in the same shape battery holders. See this thread for suitable Li-Po packs.

The ESC must have a low voltage cutoff suitable for Li-FE packs, which is 5.0v (TEU-104BK). ESCs with programmable cutoffs are suitable, where as ESCs with a Li-Po 6.0v-6.2v cutoff will not run for long before the ESC shuts the motor off.

In reality these Li-FE packs are no safer to use than hard case Li-Po packs or even Ni-MH packs. Mistreat any of them and they will all go up in smoke. To date I've only ever had Ni-MH go bang (like a grenade in my face). I've been using hard case Li-Po and A123 Li-FE cells for the last few years without issue, although I'm using 3S Li-FE (9.9v) in a custom chassis and in a boat.

Thanks for the informative reply! I already researched and discovered just about everything you mentioned as far as the lower speed and capacities. I'm not really concerned about the speed since I'm really only into backyard bashing and will be moving up from nimh anyway. One thing that you mentioned though didn't make sense to me from what I've seen...I've read that life batteries do not require extra voltage regulators..? I have a couple brushless systems that will be no problem to set the cutoff, but I'm not sure of which tamiya escs I have in the boomerang and grasshopper. I'll have to check on that. I already decided that I'll get the "skycharger" or the "thunder" charger since those are basically both the same charger and will handle life, lipo, nicd as well as nimh. I'm going to checkout the 2 links you posted now. I'd just measure my current packs, but they are at my dad's since everything was in storage over the winter.

[TA-Mark 195]

Not sure I would call Li-FE 6.6v an upgrade from 7.2v Ni-MH/Ni-Cd. They don't have as much voltage sag under load as Ni-MH, but they are still noticeably slower, with less runtime.

Don't get what you mean by: "thing that you mentioned though didn't make sense to me from what I've seen...I've read that life batteries do not require extra voltage regulators..?"

TEU-101BK has no cutoff.

TEU-104BK is the update to the 101BK and has 5.0v Li-FE cutoff, but 50% reverse/brake power.

[gba888 0]

Not sure I would call Li-FE 6.6v an upgrade from 7.2v Ni-MH/Ni-Cd. They don't have as much voltage sag under load as Ni-MH, but they are still noticeably slower, with less runtime.

Don't get what you mean by: "thing that you mentioned though didn't make sense to me from what I've seen...I've read that life batteries do not require extra voltage regulators..?"

TEU-101BK has no cutoff.

TEU-104BK is the update to the 101BK and has 5.0v Li-FE cutoff, but 50% reverse/brake power.

What I meant was that I had seen some information that stated that with life vs lipo, voltage cutoff and or regulation was much less of a concern with life batteries. I've read information that states one of the reasons lipo batteries malfunction is due to continued running at low voltages.

As far as specifics on the controllers, I know I have 2 brushless systems that offer cutoff, but I'm not sure which tamiya escs I have. The specific info you listed will be good though when I get a chance to check things out.

I found dimensions online of a pack that I believe are the same as the nimh 7.2v packs that I have. The dimensions are 135mm x 45mm x 25mm. Going by that and looking at some options here: http://www.hobbyking.com/hobbyking/store/_...ry-LiFePo4.html, I can see there there may be some options above the 2200mah capacity. The biggest issue seems to be some are around 139mm vs the 135mm length, so some modification may be necessary to make those work.

I'm still looking and *learning* about battery choices so yeah, some of the stuff I post may not make sense and may be totally wrong, that's why I'm asking in the first place

[gba888 0]

Just for anyone else who might be following the thread... I found a few different "Venom" batteries that seem like they would work as well with capacities up to 4000mAh in a hard case. Here is a link: http://www.venom-group.com/Store/LiFE That seems to be their main site, but Tower Hobbies carries these as well.

Until I get a chance to measure my exact packs or the car battery compartments, I think I'm going to hold off on actually buying anything. I think I'd much rather take the trade off of less power when considering that you can generally get about 4x the charge cycles out of life vs lipo, and you can charge them quicker as well. If you get 2 decent packs it should work out fine enough to have one charged then use the other while the first re-charges. Again, this is likely specific to *my* style of bashing/driving, but that's all that really matters to me when making the decision.

I *do* believe that going to life from nimh will be an advantage in 2 ways even considering the lower voltages...the First is that they are considerably lighter which will result in longer run times from an equivalent capacity nimh, and Second, I'm having a tough time finding nimhs for sale that seem to be of decent quality anymore. I had 2 tenergy 3800 packs that went bad on me after only a year (about 4-5 months) of use. I'll gladly pay the extra money and suffer the voltage loss if the life batteries are as long lived and "safe" as I keep reading about. Yes, I know that if abused, anything can go wrong with any type of battery...it's all about statistics though, and I just really don't like the idea of how much care you need to put into charging/discharging and handling lipo batteries. I have enough things to worry about in every day life without adding the worry of watching the batteries as they charge and taking it easy when driving so that I don't give it too much of a shock and whatnot.

[markbt73 5311]

I've been using a Hobbico 2100mah LiFe receiver pack for a few months now. I got it for my SRB, but it works so well I've started using it in other cars as well. It's only 10c, but that's plenty of current for a 540-powered car. Gives about 30 minutes of run time in my FAV. If you just want to try it out, it's not bad price-wise; Tower has the battery and a dumb plug-and-play balance charger for it for under $80 for both. Search for "Hobbico Lifesource" on Tower's site and you'll find them. It's slightly smaller than a standard stick-pack; I'm still working on making it fit the various cars.

Here's my original thread on it: http://www.tamiyaclub.com/forum/index.php?showtopic=62724

The combination of a 540-powered re-re model, a TEU104BK, and a LiFe battery really works well. No need for BEC at only 6.6 volts, and if you want to regain the "lost" speed (which isn't much to begin with), just gear up.

[Sayer 742]

This thread is making me lose my mind. I really don't understand this determination to jump through hoops to use Life when the more widely supported and exactly as safe Lipo option is available. BECs are so ubiquitous that not needing one is hardly a selling point. Lipos are only ZOMGDANGEROUS! if you're running a soft case in a car (your own fault) or if you screw up and charge it with the wrong setting. The only special treatment you need to give them when driving is to stop when the cutoff activates. Why would anyone want to mess with figuring out gearing ratios if Lipos are already too much hassle? I mean Jesus, if you're willing to accept 6v as an acceptable drop in performance for ease of use, why don't you just go back to hassle free NiCd?

[OCD 514]

The only special treatment you need to give them when driving is to stop when the cutoff activates. Why would anyone want to mess with figuring out gearing ratios if Lipos are already too much hassle?

This is the exact reason I am following this thread; Why do people prefer the LiFe batteries over LiPo? Only because the 104BK is compatible with it?

[TA-Mark 195]

This is the exact reason I am following this thread; Why do people prefer the LiFe batteries over LiPo? Only because the 104BK is compatible with it?

The only reason I fitted Li-FE cells into the models that have them is that the custom chassis and battery compartment was the ideal size for them. I'm not using the TEU-104BK ESC, instead Castle ESCs with the cutoff set at 7.5v (9.9v 3S). If it wasn't for the odd sized battery compartments I would have fitted these models with the same hard case Li-Po packs I use in my other room full of models.

[OCD 514]

The only reason I fitted Li-FE cells into the models that have them is that the custom chassis and battery compartment was the ideal size for them. I'm not using the TEU-104BK ESC, instead Castle ESCs with the cutoff set at 7.5v (9.9v 3S). If it wasn't for the odd sized battery compartments I would have fitted these models with the same hard case Li-Po packs I use in my other room full of models.

Fair point. Thanks for the clarification

I have a number of the 104BKs already on-hand and I'd like to find a reasonable use for them. LiFe batteries seem reasonable to me and it's an added bonus that they fit a wider variety of vehicles.

[GregM 1109]

I'm having a tough time finding nimhs for sale that seem to be of decent quality anymore. I had 2 tenergy 3800 packs that went bad on me after only a year (about 4-5 months) of use. I'll gladly pay the extra money and suffer the voltage loss if the life batteries are as long lived and "safe" as I keep reading about. Yes, I know that if abused, anything can go wrong with any type of battery...it's all about statistics though, and I just really don't like the idea of how much care you need to put into charging/discharging and handling lipo batteries. I have enough things to worry about in every day life without adding the worry of watching the batteries as they charge and taking it easy when driving so that I don't give it too much of a shock and whatnot.

Both LiFe and LiPo, just like LiIon, suffer from general maximum capacity load loss over the years, even if just stored without any use or charging cycles. They'll wear this or the other way from the day they are manufactured and hit the shop's shelves.

If you charge _any_ Lithium type (including LiFe) of rechargable battery for your R/Cs, just use a fireproof LiPo-charging-sack for storing batteries inside while charging. Shouldn't cost more than 10 € and will keep your house safe. That's what I do anyway to be on the safe side. And remember, even NiMH and NiCD can fire up when you accidentally shortcircuit their battery terminals.

A lot of new released modern LiFe capable chargers can charge LiPo too and vice-versa, (should be mentioned in the charger's description). A lot of today's speed controllers (only Tamiya's don't) include a LiPo cutoff. And there are even circuits available to retrofit a cutoff when using other electronic speed controllers:

http://www.tamiyaclub.com/forum/index.php?showtopic=66249

I guess LiFe batteries are incompatible to most batterie compartments due to LiFe's unique shape and dimensions. However, TA-mark has mentioned a thread where you can find LiPo batteries that will fit into almost all NiMH/NiCd stick pack sized battery compartments, even length-wise.

Please don't feel offended by my post. We all just want to help you. I respect your opionion and if you want to use LiFe by all means, that's OK and your decision. But then be aware of LiFe's limitations. To believe "a LiFe hardcase battery is safer than a LiPo hardcase battery" is a misconception.

[gba888 0]

Hi Guys,

Just checking in on the thread First off, I'm not offended by anything, as I said I'm just trying to learn here and figure out what's best for my needs. I have to admit that I've really had some fear struck into me by all the LiPo fire and explosion stories and vids on youtube. I understand that a hard case LiPo is definitely a big improvement over the older soft packs, but I can't say that I agree with the statement about one not being safer than the other when considering LiFe vs LiPo. For instance: if you run each below the cutoff level the LiFe will not be affected whereas the LiPo will. Not sure if it would catch fire or melt or whatever but from everything I've read, you won't do as much damage (if any?) running a LiFe under voltage as much as you would running a LiPo under voltage. So, from a shock/crash perspective, yes, I agree comparing 2 hard cases would be apples to apples, but considering discharging and charging, I think you need to consider the battery technology that's inside.

I'm not sure what was meant about jumping through hoops to use LiFe batteries? To me, it seems that LiPo is more about jumping through hoops when you consider how careful you need to be with charging, discharging, charging in a fireproof bag, not bashing "too hard". On the other hand you have LiFe where you simply change your pinion? And that's only if you have a problem with slower speeds. Am I missing something here? Again, I'm not being smart or whatever, I'm just asking because I really don't know.

As far as chargers, the skycharger or thunder charger can be had for around $60 and those will charge anything from nimh to lipo to life to nicd. Getting a new charger isn't really an argument in my case because whether I'd go with Lipo OR LiFe, I'd still need a new charger.

Ultimately here is how I see it:

LiFe = technologically safer, considerably more charge/recharge cycles, slower speeds due to 6.6v

LiPo = potentially dangerous unless utmost care is taken, considerably fewer charge/recharge cycles

[GregM 1109]

With a LiPo capable speed controller or a seperate cutoff circuit, your battery won't ever get damaged by deep-discharge. The car will just stop at a preset low voltage level, before reaching deep-discharge. And even using a non-LiPo capable speed controller, all what the deep-discharge is doing is just making the battery permanently loosing some or all of it's maximum capacity. There's no rule that it has to burst in flames then The same goes for LiFe.

You can always bash hard using a hardcase LiPo, badword, most people do already. What you are seeing on those web videos you mentioned is mostly abuse on purpose. Don't let them shock you too much, and use hardcase LiPo in R/C cars to be on the safe side, as lighter and flexible softcases are better used in R/C planes. I'm glad you're asking us for advice.

[gba888 0]

With a LiPo capable speed controller or a seperate cutoff circuit, your battery won't ever get damaged by deep-discharge. The car will just stop at a preset low voltage level, before reaching deep-discharge. And even using a non-LiPo capable speed controller, all what the deep-discharge is doing is just making the battery permanently loosing some or all of it's maximum capacity. There's no rule that it has to burst in flames then The same goes for LiFe.

You can always bash hard using a hardcase LiPo, badword, most people do already. What you are seeing on those web videos you mentioned is mostly abuse on purpose. Don't let them shock you too much, and use hardcase LiPo in R/C cars to be on the safe side, as lighter and flexible softcases are better used in R/C planes. I'm glad you're asking us for advice.

Thanks for the clarification on the discharge and what will/will not happen Yes, I definitely had the mental image of running along then all of a sudden the car bursts into flames because the voltage dropped to 3.2v instead of 3.3v LOL.

I know a lot of the videos are of people hitting them with sticks with nails in and purposely TRYING to make them explode. The ones that have got to me though are the ones where they are just driving the cars and they start smoking (not necessarily catching on fire, mind you). I've seen quite a few vids with people having LiPo failure mid-flight in planes and whatnot also, but obviously, that's going to do a lot more damage considering the circumstances and could happen with the failure of ANY type of battery.

How about this...my MAIN number 1 concern *above all* would be.....the battery while in storage (not being charged/discharged)...just catches fire or has a "meltdown". Any records of *that* ever happening? That's a big concern of mine since I store a lot of my rc stuff for a good bit of the year. I mean if it catches fire while charging...big deal you can put it out. If it catches fire or implodes/explodes in your car...you can get another (in most cases). But...if it sparks a fire in storage.....THAT would be very, very bad. Maybe that's bordering on paranoia, but I figured I'd ask anyway

[atf300 28]

Thanks for the clarification on the discharge and what will/will not happen Yes, I definitely had the mental image of running along then all of a sudden the car bursts into flames because the voltage dropped to 3.2v instead of 3.3v LOL.

I know a lot of the videos are of people hitting them with sticks with nails in and purposely TRYING to make them explode. The ones that have got to me though are the ones where they are just driving the cars and they start smoking (not necessarily catching on fire, mind you). I've seen quite a few vids with people having LiPo failure mid-flight in planes and whatnot also, but obviously, that's going to do a lot more damage considering the circumstances and could happen with the failure of ANY type of battery.

How about this...my MAIN number 1 concern *above all* would be.....the battery while in storage (not being charged/discharged)...just catches fire or has a "meltdown". Any records of *that* ever happening? That's a big concern of mine since I store a lot of my rc stuff for a good bit of the year. I mean if it catches fire while charging...big deal you can put it out. If it catches fire or implodes/explodes in your car...you can get another (in most cases). But...if it sparks a fire in storage.....THAT would be very, very bad. Maybe that's bordering on paranoia, but I figured I'd ask anyway

you're being too paranoid, but one can get that idea when researching lipos , as there's plenty of disaster videos around. the chances that a battery will catch fire in storage are more or less the same as with nimhs. threat the battery well and all is well. you can also go the way of some people who make storage boxes which have sand on top of batteries so if the battery catches fire it gets extinguished with sand . google storing lipos in ammo boxes .

[gba888 0]

you're being too paranoid, but one can get that idea when researching lipos , as there's plenty of disaster videos around. the chances that a battery will catch fire in storage are more or less the same as with nimhs. threat the battery well and all is well. you can also go the way of some people who make storage boxes which have sand on top of batteries so if the battery catches fire it gets extinguished with sand . google storing lipos in ammo boxes .

"google storing lipos in ammo boxes " LOL not really what I wanted to hear, but yeah, that really did make me laugh out loud I'll look into that and see what I find.