storage or discharge?

[simalarion 133]

8 minutes ago, mud4fun said:

Incorrect!

Most of my NiCd packs are 8.4v, and they deliver that 8.4v for the far greater duration of a 5 minute race than LiPos which reduce to 7.6v by half race distance.

LiPos have only two advantages for me and that is weight and runtimes - you couldn't get a 5000mah NiCd 20 years ago (and after allowing for the loss of bottom 20% of charge the capacity is not massively better)

Performance is actually minimal difference between a 2S LiPo and an 8.4v NiCd over a 5 minute race - trust me, I've done thousands of race laps using them back to back. The only gains have been in weight NOT voltage.

LiPos suffer from over hype from people that have simply had bad experiences with cheap and nasty NiMh's - had they experienced quality NiCd's their attitudes would be very different.

 

 

I have two 5000 Mah NimH batteries right now and so far they do the job, but i am currently building a Agrios with 2 x 540 motors and 2x High Torgue metal gear Servos 25 kg so i belive that is a bit more Battery hungry and i would gain from a LipO change (?). I aslo think there is good space for Lipo in Agrios but the build is not done just yet  ... 

 

Thanks for all the help/sugestions so far *thumbs up*

[mud4fun 1397]

This is about 90% of our battery stock, some of the LiPos are still fitted in cars after running today but this gives an idea of what I have experienced.

From left to right:

• Tamiya 7.2v 1400 NiCd packs (20 years old) - over 1000 charges per pack and still retaining 90% capacity (exclusively discharged/charged using the PRO Peak super nova)
• Sanyo 7.2 2000mah NiCd packs (18 yrs old) - over 2000 charges per pack and still retaining 80% capacity (exclusively discharged/charged using the PRO Peak super nova)
• Absima 7.2V 3600mah NimH (6 mths old) - lost 20% of capacity after just 20 charges - basically junk! (exclusively discharged/charged using the PRO Peak super nova)
• Overlander 7.2v 3300 NiMh (3 mths old) - lost 30% capacity after just 50 charges - junk (charged using the SkyRC T100 for first few charges, then using pro-peak thereafter)
• Sanyo 8.4v 2000mah NiCd (18yrs old) - over 2000 charges per pack and still retaining 80% capacity (exclusively discharged/charged using the PRO Peak super nova)
• Sanyo 9.6v 2000mah NiCd (18 yrs old) - less than 100 charges,   still retaining 95% capacity (exclusively discharged/charged using the PRO Peak super nova)
• Absima 2S 5000mah LiPo (3 mths old) - still retaining 100% capacity (exclusively discharged/charged using the SkyRC T100 on storage charges and then balanced charges 1 hr before use)
• Absima 2S 4000mah LiPo (3 mths old) - still retaining 100% capacity (exclusively discharged/charged using the SkyRC T100 on storage charges and then balanced charges 1 hr before use)
• Sanyo 2400mah receiver pack (18yrs old) - less than 100 charges,   still retaining 95% capacity (exclusively discharged/charged using the PRO Peak super nova)

So from my experience of all these packs over 20 years of use I can honestly say that I am far from impressed with LiPo and find it massively over hyped. NiMhs are basically junk. Nothing can compare to the Sanyo NiCD's for value for money, longevity and sheer number of charge cycles they can take.

 

The Sanyo NiCd's do not lose any significant capacity when stored and I can take out a 7.2v 2000mah pack from storage and fit it to my crawler and get 60 minutes run time from it. None of the hassles of LiPo and to be honest in a crawler the heavier battery often works out better especially when doing mud bogging or running on muddy ground. LiPo is however superb in my race buggies where lightweight is critical.

 

[simalarion 133]

21 minutes ago, mud4fun said:

So from my experience of all these packs over 20 years of use I can honestly say that I am far from impressed with LiPo and find it massively over hyped. NiMhs are basically junk. Nothing can compare to the Sanyo NiCD's for value for money, longevity and sheer number of charge cycles they can take.

NiCD is new information for me, i have googled after them but is this a cind fo NimH battery or what?. 

[mud4fun 1397]

20 minutes ago, simalarion said:

NiCD is new information for me, i have googled after them but is this a cind fo NimH battery or what?. 

NiCd's (Nickel Cadmium) were 'banned' under EU rules about 15 years ago as far as I can remember, due to 'environmental' reasons.....

However just like most things with 'green' regulations it ends up being less green than the thing it replaced.....

NiCd's that last 2000-3000+ charges are in my opinion better for the environment than a NiMh that last just 100 charges before being scrapped.... but heck, what do I know? I'm just an idiot that finds NiCd's last 10-20x longer than NiMhs in real world use..... 

Oh and my 1:1 Land Rover is 50 years old and is still more reliable and still going strong compared to my 3 yr old modern pickup truck which is horrendously unreliable and has cost 10x more to own in past 3 years and is already showing signs that it will die in the next few years..... I have a growing sense that modern doesn't always mean better! 

[simalarion 133]

25 minutes ago, mud4fun said:

NiCd's (Nickel Cadmium) were 'banned' under EU rules about 15 years ago as far as I can remember, due to 'environmental' reasons.....

However just like most things with 'green' regulations it ends up being less green than the thing it replaced.....

NiCd's that last 2000-3000+ charges are in my opinion better for the environment than a NiMh that last just 100 charges before being scrapped.... but heck, what do I know? I'm just an idiot that finds NiCd's last 10-20x longer than NiMhs in real world use..... 

Oh and my 1:1 Land Rover is 50 years old and is still more reliable and still going strong compared to my 3 yr old modern pickup truck which is horrendously unreliable and has cost 10x more to own in past 3 years and is already showing signs that it will die in the next few years..... I have a growing sense that modern doesn't always mean better! 

Oh, its possible that had NiCds in my Blackfoot when i was around 11 then, very sad thing that i was not very good taking care at my things so all gone.  

But yeah many things was built to last longer before, like they build phones so you should replace them after ca 2 years today. 

[Juggular 3432]

33 minutes ago, mud4fun said:

I am far from impressed with LiPo and find it massively over hyped

For me also, it doesn't make a whole lot of difference (because most of mine are using Sport Tuned). 

Brushed motors use about 1-1.5A burst, about 0.5A steady.  So yeah, old NiCd, NiMH, would do just fine.  It's hard to find NiCd in good condition. But if it is in good condition I believe it can work better than mediocre NiMH.  NiCd tends to have higher discharge rate than NiMH. LiPo has even higher discharge rate, but the question is how much the motor is drawing.    

The real test is on hot brushless motors.  They can use 3A burst, 1-2 A steady.  Even NiCd can supply 2A.  So it would limit potential burst down to 66%.  It's not the end of the world.  But for people who are running motors faster than 13.5 or 3000kv, they can see the improvement in their acceleration.  

 

[mud4fun 1397]

20 minutes ago, Juggular said:

For me also, it doesn't make a whole lot of difference (because most of mine are using Sport Tuned). 

Brushed motors use about 1-1.5A burst, about 0.5A steady.  So yeah, old NiCd, NiMH, would do just fine.  It's hard to find NiCd in good condition. But if it is in good condition I believe it can work better than mediocre NiMH.  NiCd tends to have higher discharge rate than NiMH. LiPo has even higher discharge rate, but the question is how much the motor is drawing.    

The real test is on hot brushless motors.  They can use 3A burst, 1-2 A steady.  Even NiCd can supply 2A.  So it would limit potential burst down to 66%.  It's not the end of the world.  But for people who are running motors faster than 13.5 or 3000kv, they can see the improvement in their acceleration.  

 

Yes, my 2S LiPos are 45C and I can honestly say they are no better than my 8.4v Sanyo NiCd's, in fact I'd say my 8.4v NiCd's were superior for outright acceleration and maintaining that burst of power over longer race distances,

The Absima square section Lipos cost me approx £30 each, my 8.4v Sanya NiCd cost approx £20 each 20 year ago so in terms or price (allowing for inflation) the NiCd's were almost twice the price BUT they have lasted 20 years and still give 80% capacity and same performance as a modern 45C LiPo. I guess if you spend £40+ on a LiPo with higher discharge rate then sure it will be better than my 8.4v NiCd's but I'd suggest that value form money (and environmental friendliness) goes to the NiCd.  

All my 8.4v NiCd's and 2S LiPos's are used with either 19T reedy spec brushed or 13T dyna run super touring brushed motors,

 

PS. We have done GPS tests on my buggy and its 8.4v NiCd/13t Dyna Run Super Touring annihilated a buggy running a 13.5T brushless LiPo setup...... (I shouldn't mention the fact that the Dyna Run on a 9.6v slaughtered a Brushless 3S setup..... oh how funny that was, too many people dismiss brushed as old hat until they get destroyed by a vintage motor )

[Wooders28 3139]

3 hours ago, mud4fun said:

Most of my NiCd packs are 8.4v,

Presumed you where 6 cell 7.2v, we weren't allowed to run 7 cell.

3 hours ago, DayRider said:

There is one thing I have found that having less weight with lipo, nihm batteries work better when the ground is damp.

You're better leaving in a Lipo ,and putting weight where you need it?

[mud4fun 1397]

24 minutes ago, Wooders28 said:

Presumed you where 6 cell 7.2v, we weren't allowed to run 7 cell.

uh? why would you compare an 8.4v (charged) 2S LiPo pack with a 7.2v NiMh? that is a rather silly comparison surely as the 8.4v will always give better performance than the 7.2v? If I compared performance of my 9.6v NiCd to your 2S LiPo it would slaughter you but it would be an unfair comparison. Compare like for like. If your race organisers doesn't allow 8.4v NiCd's BUT DOES allow 8.4 LiPo then they are idiots. The 8.4v NiCd already carries a heavy weight penalty (150g+) so hardly like it is an unfair advantage BUT allowing 8.4v LiPos that are 100g lighter than 7.2v NiCd or NiMh packs is surely an equally unfair situation????

My quoted experiences are in like for like head to head comparisons. If you want to compare totally dissimilar batteries then you should make it clear?

 

[Raman36 629]

11 hours ago, Nicadraus said:

Storage mode is supposed to be done when the batteries won't be used for at least two weeks or more. I only discharge my batteries after a full day usage or event race then store charge after.

Well you need to clarify this. If you leave a LiPo full charged for over a week, it will still not be happy either. If the weather in your area is also warm or hot, it will make matters worse, especially if they are full charged. 

After 10 years of racing, I have become religious on putting batteries into storage mode at the end of the day of usage.   The results have been batteries lasting close to 2 years! Additionally in summer month, I keep them in the fridge while in storage mode. 

[mud4fun 1397]

1 minute ago, Raman36 said:

  The results have been batteries lasting close to 2 years! 

uh??????

If my batteries ONLY lasted 2 years I'd be pretty P'd off. How many charge/use cycles is that?

If a LiPo costing £30 only lasts 2 years at best then that is atrocious value for money and simply not worth the money unless you are racing at national levels.

Most of my NiCd's have lasted nearly 20 years and over 2000 charge/use/discharge/charge cycles. The minimal performance gains for LiPo are simply not worth the expense for bashing or non competitive racing IMHO. Just fit a smaller pinion and get more run time from the NiCd's/NiMhs?

[mud4fun 1397]

@Wooders28 why the confusion?

You claimed a 2S LiPo gave better performance than a 7.2 NiCd/NiMh - of course it would but that is like me saying my 240hp V8 Land Rover has better performance than my 60hp 2.25 diesel Land Rover, not comparing like for like and therefore a totally invalid comparison. 

Anybody talking about the comparative performance of LiPo vs NiCd/NiMh should be honest and compare a 2S versus an 8.4 NiCd/Nimh as that is the closest in terms of voltage when fully charged. If they did that there would not be so many false stories of LiPo being so incredible in performance as it is simply not true.

Also a typical 2S LiPo is up to 150g lighter than an 8.4v NiCd and 100g lighter than  a 7.2v NiCd so the gains in performance are little to do with increased voltage or current but more to do with reduction in weight. I have proven this by adding ballast to a LiPo powered buggy so it weighed same as the NiCd equipped buggy, the NiCd then won every race. The LiPos primary benefit is lower weight.

I also get fed up of people saying LiPo's give longer run times than NiCd's/NiMhs - this is silly if you are comparing a 2000mah NiCd with a 5000mah LiPo - naturally the 5000mah will give longer run times but that has nothing to do with whether it be LiPo or NiCd, you are simply comparing relative capacity not battery chemistry. Divide your laps on LiPo by the capacity and do same on NiCd and you'll  end up with roughly the same number of laps per 1000mah capacity (other than the LiPo will achieve slightly more laps simply down to lower weight).

So in summary the main advantage with LiPo is low weight which is largely irrelevant to 99.999% of RC car users who do not race. The main benefit for non racers is increased capacity available on LiPo compared with NiMh/Nicd BUT for the hassle, costs and potentially shorter life it may well be worth simply buying two cheaper NiCd/NiMh packs rather than one large capacity LiPo. It only takes a few seconds to swap a battery and for bashing it may prove more cost effective? My daughters still use NiCd packs and they have 4-6 packs each. That gives them hours of use per buggy when out bashing or racing. They don't really have any issue with that and in many ways spreading the load over multiple packs may give increased life?

 

 

[Nicadraus 1910]

2 hours ago, Raman36 said:

Well you need to clarify this. If you leave a LiPo full charged for over a week, it will still not be happy either. If the weather in your area is also warm or hot, it will make matters worse, especially if they are full charged. 

After 10 years of racing, I have become religious on putting batteries into storage mode at the end of the day of usage.   The results have been batteries lasting close to 2 years! Additionally in summer month, I keep them in the fridge while in storage mode. 

I never leave my batteries full charge. 

[Juggular 3432]

4 hours ago, Raman36 said:

If you leave a LiPo full charged for over a week, it will still not be happy either. If the weather in your area is also warm or hot, it will make matters worse, especially if they are full charged. 

I got curious as to how long you could keep LiPo fully charged, and I came across this.  In warm area, up to 40% of the capacity dies in 3 months.  13% per month, 3% per week.  That seems a lot. 

For the same reason, I usually use my ipad half-capacity.  I use it until 30%, and recharge up to 80%.  So I'm just using the middle 50%.  I rather get bored with my ipad in 3-4 years than having the battery give up on me.  I use it mostly in my room. So I don't have to worry about how long it would last anyway.  Once in a blue moon, I'd take it somewhere for a day or two, only then, I'd charge to like 100%.  

"A battery sitting at room temperature fully charged will loose about 20% of its capacity in a year. A battery sitting at 60 degrees Celsius will lose 40% of its capacity in just 3 months."

 https://brushlesswhoop.com/storing-fully-charged-lipo-batteries/

 

Edit to add a couple of videos:

This Japanese guy compared two batteries on two different motors.  

Below is a screenshot of 10 meter sprint. 

1600 NiCd vs 4000 LiPo 30C.  

The weight difference is 90 grams.  That's about the weight of 4-5 AA alkaline batteries.  It's substantial difference.  However, it hardly makes any difference to the silver can (0.04 second).  I think this is because it draws so little electricity, it simply cannot take advantage of the high current supply.  You can give a big beer mug to a 5 year old girl.  But the girl will drink at her own pace (water, not beer).  But grown men like us, have gulped beer down really fast when we were younger.   

The battery itself didn't change weight.  But Sport Tuned runs 0.13 second faster with LiPo.  Probably because Sport Tuned can use more current.  

This guy does another test comparing just batteries using a 10.5t motor.  It's a faster motor than Sport Tuned.  

 

The difference between LiPo and NiMH at full charge is actually just 0.2 volt.  But LiPo drops down to 5.9 v at hard acceleration, but it comes back up to about 6.5v.  NiMh drops down to 3.3v but it doesn't come above the 5v line.     

The amp draw reflects this.  LiPo draws about 50% more amp than NiMH.  Mind you, this is a fraction of a second.  

Max RPM does about the same too.  More voltage and current would give you higher RPM.  

At the end, he adds NiCd too.  Interestingly, it does keep up at around 5v when NiMH falls down to 3.3v.  But while NiMH is on the recovery at 1 second mark, NiCd drops down to 2.7v.  

As I've said, I'm using mostly Sport Tuned and 13.5t.  Sport Tuned draws much less power than 10.5t.  So LiPo is only faster by 0.13 second, hardly noticeable when you are just bashing.  LiPo or NiMH, most brushed motors would not make a lot of difference.  Silver can? Not at all, even though LiPo is lighter. 

But if you are using something faster than 13.5t (like 10.5t), then it can make a difference because 10.5t is a thirstier motor.  The more power the motor consumes, the better LiPo would shine.  After 1 second, LiPo is above 6.5v.  NiMH is below 5v.  Many of us have used 8.4v in the past, it's a lot faster than 7.2v, and that's only 1.2v difference.  So 1.5v difference between LiPo and NiMH would be felt. (again, only if you are using something faster than 13.5t. Or a 13.5t with a lot of advanced timing)  

 

[Wooders28 3139]

7 hours ago, mud4fun said:

You claimed a 2S LiPo gave better performance than a 7.2 NiCd/NiMh - of course it would but that is like me saying my 240hp V8 Land Rover has better performance than my 60hp 2.25 diesel Land Rover

So, you agree!! 🤦‍♂️

Both 6 cell nimh and a 2s Lipo are pretty much the same voltage fully charged,  so to compare which chemical composition makes a better battery, you'd compare a 2s to a 6 cell nimh.

A 7 cell nimh is closer to 9.7v fully charged, and not 8.4v, which was my confusion.

 

[mud4fun 1397]

25 minutes ago, Wooders28 said:

So, you agree!! 🤦‍♂️

Both 6 cell nimh and a 2s Lipo are pretty much the same voltage fully charged,  so to compare which chemical composition makes a better battery, you'd compare a 2s to a 6 cell nimh.

A 7 cell nimh is closer to 9.7v fully charged, and not 8.4v, which was my confusion.

 

LOL, not really.

I still stand by my experience that the difference in chemical composition doesn't give me much of a performance gain OTHER than from weight savings. Once you ballast out the difference there is minimal performance difference. On LiPo my buggy is 150g below the BRCA minimum race weight for a 4WD buggy so I'd have to add 150g of ballast anyway. Not that I'd enter it into a BRCA event but you get the point.

Could just be that my Absima 45C LiPo's are poor but my 13T motors definitely give similar lap times with the 7.2v NiCd and better with 8.4v NiCd, the 8.4v worth up to 0.5 second a lap more despite the weight penalty. The biggest gains in my case were weight related, dropping 150g from race weight significantly increases performance, mainly through quicker cornering in my lowered buggy. I've done a few thousand laps now on a tarmac track using a transponder timing system and measuring to hundredths of a second so my claims are not based on 'gut feel' or anything, they are genuinely from timed and quantifiable results.

However as @Juggular stated above, this could very well be down to motor choice. My most powerful motor being a 13T Dyna Run super touring which is probably not as power hungry (especially running a small pinion) as your motors?

Let me put it another way - I got much more significant gains in lap times from lowering the buggy and using super soft compound carpet tyres than I gained from using LiPo!

 

EDIT: In changeable weather the NiCd's win hands down over LiPo. If I get a good weather window I just want to grab a battery and a car and go drive. Sadly with the LiPos all stored at storage charges I have to charge them before use, this can take an hour on a 5000mah LiPo so I end up missing my weather window. That has happened several times over last few weeks and is getting damned annoying. The NiCd's (stored fully charged) are a dream to use in comparison.

 

[Wooders28 3139]

19 minutes ago, mud4fun said:

My most powerful motor being a 13T Dyna Run super touring which is probably not as power hungry (especially running a small pinion) as your motors?

My slowest race car (and race truck), run 6.5t and my race 4wd runs a 4.5t with 3800mah 110C ,5100mah 65/130c, 2s batteries respectively. My slowest brushed runs 15t motors (Bullhead).

I've never tried the race cars on nimh, (8.4v or 9.7v) , i dont think they'd fit for a start, so can't really say, but did run Nimh on a 5700kv Dark Impact but only 6 cell, and 2s was a massive difference, and then went to 3s....🙄

[simalarion 133]

This get complicated pretty fast , much to learn and take note from here. So some do not reckomend SkyRC becouse it can "ruin" battery capacity, so which Charger can you suggest that is aviable at Tamico etc ?, i would like the charger to take both NimH and LiPo 

[taffer 660]

My skyrc d100 dual charger is and has been great, over two years, no issues

[mud4fun 1397]

3 hours ago, simalarion said:

This get complicated pretty fast , much to learn and take note from here. So some do not reckomend SkyRC becouse it can "ruin" battery capacity, so which Charger can you suggest that is aviable at Tamico etc ?, i would like the charger to take both NimH and LiPo 

Just make sure that whatever charger you get will allow discharging NiMh if you only want to use one charger. The SkyRC T100 will not discharge NiCd or NiMh, only charge them. You need to fully discharge them after use and before charging to maximise their life. The SkyRC T100 is more geared to LiPo users than older batteries. It was annoying to find that out after I had bought it but not a massive issue, I just continued to use my old NiCd/NiMh friendly chargers for the older packs and use the SkyRC for the LiPos. In fact in may ways it is better to have multiple chargers so I can charge lots of packs at once (Kids and I often have 6-8 packs to charge after racing)

It may be my unit is faulty but it has now happened over multiple packs, the SkyRC fails to fully charge the NiCD/NiMh packs and after several charge cycles they show significant loss in capacity. This doesn't happen on my Propeak super nova. 3300 Packs that only took 2800mah on the SkyRC T100 take 3200+ on the supernova. That is significant difference. The T100 and supernova were both set with the same charge rate too. I only charge my NiCd/NiMh packs on the supernova now.

[El Gecko 294]

I don't do LiPo, but for NiCd and NiMH I leave them discharged during storage. If it's long term storage I discharge them as much as possible by hooking them up to a car with an MSC and letting it run out with the wheels off the ground. On a nearly dead pack, it's not long until the wheels stop turning. For short-term storage, or if I'm doing a lot of charging and running, I don't bother discharging past the point where the car stopped moving under its own power.

It takes a few charges to bring them back up to speed after a long slumber, but they always come back unless they were damaged in some way. Even the ancient Tamiya hardcase 1200s from the 80s. I recently went to NiMH for longer runtimes and it's basically the same story. I got a Dynamite Prophet Sport Mini charger so I could charge NiMH, and it also does LiPo, LiFe, and LiHV. It's a tiny little brick of a thing, but seems well-made, and it has worked perfectly so far.

[Matty36 125]

My view is as a racer, not a basher, using nicad, nimh and lipo over the last 20 years.

The nicad batteries were only 6 cell, so 7.2v, 7 cell batteries were not allowed in a race buggy. During the 5 minute race, you were lucky to get a few laps practice followed by the 5 minute race, that was if the brushed motor didn't have a sticking brush, or the battery would slow down in the last lap.

The nimh batteries again were 6 cell 7.2v, and lasted a bit longer without going slow after 4.5 minutes. Brushless motors started appearing but I didn't make the change until 2005 or 2006. If it was too hot, the battery would stop charging early.

Lipo batteries are 7.4v, as we only use the 2s ones, and now couple that to a brushless motor, we can now do 5 laps practice, 5 minute race, slow lap at end and never see a drop in power. Now I can do 2 races without even charging the battery.

I think lipo is good, now life 7.6v batteries are out and supposedly safer. I would be more than happy only getting one race season out of a lipo, as nicad and nimh batteries did last a few thousand charges, but I much prefer the modern types, with no motor to skim and change brushes every 2 races, the cost now is minimal in comparison I think.

[simalarion 133]

MaXam Balance Charger/Discharger Pro 5000 This has a discharge and are pretty cheap in this "toy store", what i know Maxam is a known manufacturer of NimH battery?. Should i go for this that has a discharge also?

 

[Juls1 1236]

7 hours ago, mud4fun said:

 

Could just be that my Absima 45C LiPo's are poor

 

If they are the same abisma 45c lipo’s I had, those where the worst batterys I’ve ever owned. I also had some nvision 45c lipo’s and again terrible. 
 

lipos can be a bit fickle, some styles of packs can be dramatically better than the rest. The figures and ratings on the packs seems to have little bearing on how good they really will be.  I’ve had a lot of luck with 20c and 30c cells from varying manufacturers including nvision and turnigy. 
 

I hate nimh battery’s, nothing will convince me to use nimh over lipo for my “personal use”. but I miss Sanyo nicads, they where the best. Sadly I can’t buy those anymore. 
 

nimh is still the best option when gifting rc to children or the uninitiated. Lipo’s are just too fickle to proper care and so very easy to destroy if you don’t know what your doing.

[Raman36 629]

On 11/17/2020 at 4:08 PM, Raman36 said:

Well you need to clarify this. If you leave a LiPo full charged for over a week, it will still not be happy either. If the weather in your area is also warm or hot, it will make matters worse, especially if they are full charged. 

After 10 years of racing, I have become religious on putting batteries into storage mode at the end of the day of usage.   The results have been batteries lasting close to 2 years! Additionally in summer month, I keep them in the fridge while in storage mode. 

I use them regularly for racing, I’m looking at 4 cycles each race day per pack  .. so roughly 150-160 cycles per year.  That doesn’t factor in bashing in front of the house with my son either. So 2 years for LiPo is actually really good. 

Lipos are not a minimal performance gain, that is a severe understatement. A 5000 mah LiPo will give you 30 minutes of bashing on a silver can / stock motor.  You will have consistent linear power and plenty of punch during the entire run. You will only notice a drop in speed in the last 3 min before you hit the voltage cutoff.  You can actually use 4300 mah of the 5000 capacity. 

With NimH and NiCd, a 3000 mah pack, you’re lucky if you can use 1500 man of it before it needs charging. You will also notice a voltage drop when pack drains to even 20%. Run time, you’re lucky to get 10 minutes.. in racing 5 minutes as Matty36 wrote.

Bottom line, with LiPo you may end up board before the battery runs out.. where as with NiCd/ NiMh they die just when you’re starting to have fun