Boring battery review

[flydiver]

If you've been at this awhile you already know the oft repeated question is 'What's the best and cheapest lipo out there? Tough question, been asked about 10,000 times already, answers are ALL over the map, and the only thing that is more rampant than the opinions is the proliferation of same.
I don't have an answer to that question-just my own opinions and experiences. If you're here for that, may as well move on. I would advise you to do your homework, learn as much as you can, and buy a good reliable charger. It'll be the cornerstone of your lipo fleet. I studied this for a LONG time and am strongly in the FMA Cellpro 4S camp, been there a year, continue to study the issue and for less than $100 see no reason to change.
For, lipos, if it's really cheap, well it's probably really cheap. There are some bargains but it can be a frustrating and moving target. If it's on eBay and cheap - let the buyer beware.

This is for those still flogging NiMh chemistry and working with it for awhile for whatever reason.

Like everyone I started with some PZ stock batteries, wanted more power and longer flights, and tried out a few things. To start I didn't know LVC from an RTF, and certainly didn't understand much about charging so maybe made some mistakes but I've got some very limited long term opinions.

The stock PZ batteries aren't too bad. I've got a couple that are still going after well over a year of use. For what you get they are a bit expensive but if you don't like experimenting they'll do. Several have died in a year's use, and a couple are still going. I have no good idea why. Interestingly my best ones have been 6-cell, not suitable for the Cub. Did not try 8-cell PZ.

My first replacements were $20 for a pair of 1100mAh 7-cell from here:
www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=850
Seemed like a GREAT deal. 2 batteries, and bigger, for the price of 1 PZ battery. In reality they maybe had 90% of the performance AND duration to start and both were dead within 6 month of pretty decent care since I had learned a bit about batteries by then. This may be OK if you just want a temporary bridge to lipo, not if you want long term battery life and performance. They will disappoint.

I also picked up some Elites from cheapbatterypacks.com, 7-cell and 8-cell. Price is competitive with PZ. The 7-cell was a revelation, 1500mAh in the same size package, better power, longer flights, and it's still kicking strong. I actually could tell the difference in flight.

Of course the 8-cell CPB was GREAT. I know it's not a lipo but for a drop-in replacement without lipo worries, changes and hassles it was a nice upgrade in performance. The 2 of them are still working well. I think I can recommend the CPB packs as a best choice option.

For 8-cell I needed to get a new charger since the PZ that comes with the Cub won't work. I ended up getting a PZ, Great Planes, and Apache NiMh chargers. Best one seems to be the Great Planes - I use it most. Most versatile is the Apache since it'll do lipo chemistry also but does not balance. I actually use it seldom but it has lots of charging options that are occasionally useful, primarily for slow charging.

I had a number of the PZ chargers die. Those that lived past a few months are still working and get service occasionally. I'd suggest if you need an upgrade or yours dies and is not a warranty replacement to get something better.

I you are serious about transitioning out of NiMh and into lipo it seems like lots of folks get hung up in the idea that they need something that will do EVERYTHING, plus plug directly into the wall. That is possible but not for under $100. I think the reality is that once you leave NiMh, you likely aren't coming back. My NiMh are legacy for one plane that just is not (easily) feasible to use anything else on (Aerobird Challenger). The chargers I have are fine for their limited use. Yours probably will be too. Concentrate on a GOOD lipo charger. You know my opinion.

fly

5/17/09 update:
An update is that the GP charger is acting flaky so I don't recommend it anymore.
The CBP Elite battery is dying, in this case likely from neglect and disuse. I HAVE since learned that HIGH CAPACITY NiMH are MORE fragile than lower capacity. That's a general statement as there is easily wide differences in battery quality-any battery. So the Elite is a great battery but will not last a LONG time I think. You may get a year or 2 out of it but maybe that will be plenty. Better than 6 months.

Remember I said my 6-cell are still going (never strong, but going). They are lower capacity and don't get as hot when working. The elites got quite hot. Heat is the enemy of NiMh. I think over time it killed them. Not a big loss as I seldom use them anymore.

I have picked up a Duratrax Pirahana:
www.duratrax.com/caraccys/dtxp4005.htm
Very good charger but a bit more complicated since you have to set everything on it. NOT worth it if you are moving to lipos. I have a bunch of NiXX I use for other applications so it is useful to me. I have a LOT more control and info about charging now.

[sleddog]

[quote author=flydiver board=batt thread=1648 post=1

You know my opinion.

fly



[/quote]

FLY;

Thanks for these wise words. I have listened to you in the past with good results...Your dead cell call was right on the money. I just made the switch to Lipos with the PKZ Corsair. I bought the Cellpro and feel quite comfortable with it. It was highly recommended by everyone else too. This cellpro book and your pointers are teaching me how to monitor battery performance.

I know now that I will switch over to the Lipos in the Cub at some point soon...My two remaining batteries are showing their age and don't seem to last as well... Maybe because I am using aileron servos and have really flattened the wing? Keep posting your thoughts here...They are most helpful!

Thanks

[flydiver]

I doubt the upgrades have much to do with the batteries. The servos draw a little but not significant during a powered flight. What is happening is they are getting old, you have gotten better, so you hammer them harder-probably spend most of the flight at WOT. They get hot from more power draw during flight and heat is not good for them. They are just showing the results.

Yeah, the Cellpro is great. 2 of the most critical purchases for continued success in RC are a good TX and charger. They are the foundation that everything else works off of.

Thanks for the nice words.

fly

[duck]

also picked up some Elites from cheapbatterypacks.com, 7-cell and 8-cell. Price is competitive with PZ. The 7-cell was a revelation, 1500mAh in the same size package, better power, longer flights, and it's still kicking strong. I actually could tell the difference in flight.

Of course the 8-cell CPB was GREAT. I know it's not a lipo but for a drop-in replacement without lipo worries, changes and hassles it was a nice upgrade in performance. The 2 of them are still working well. I think I can recommend the CPB packs as a best choice option.

Are these ok for a stock cub, what kind of improvement can I expect. Up here in canuckistan, shipping and duty play havoc with pricing.

I really want the mah's though.

[flydiver]

Of course they are OK - that's why it's a boring review. They aren't extraordinary/super/incredible/etc., they won't blow your socks off, they won't tear the wings apart. Sigh, they won't even melt down your ESC. You won't even have to suffer through me telling you to down prop.

For the 7-cell you get a tad more performance and probably 20-40% more time-hard to be more precise since everyone flies so much differently.

For the 8-cell you get noticeable increase in performance. You take off, loop and fly with something approaching authority instead of just getting by. You will not get an increase in time-maybe less. You have to stuff 1 more cell in there which takes out of the capacity of the total. Plus you get more power so the tendency is to use it so your 'gas mileage' suffers due to lead thumb. They increase the pain involved in stuffing them in that awful battery box. Why oh why didn't they make that just 1/8" larger in all dimensions?

fly

[duck]

Thanks,

Just need to check pricing on the packs, and figure in the shipping etc.

I already noticed a steep decrease in fly time with the extra voltage of the PZ 8 cell, I'd imagine the same thing would happen with any 8 cell as opposed to a 7 cell of the same Mah rating.

[flydiver]

I"ve got an aerobird that I fly with 6 and 7-cell NiMh. They both have about the same mAh. The 6-cell has aneimic performance but actually flies longer than the 7-cell.

Think of 2 buckets, one with a large hole and one with a smaller hole. mAh is the water put in and the hole size is the draw (performance). Bigger hole will empty a bucket of any fill faster than the same amount in the smaller hole bucket.

fly

[duck]

I'll have to do some reading to see just how much amperage a SC motor/esc can take without a meltdown. I'd be willing to modify the battery box and play with the CG if I could use a 2000 mah pack

[flydiver]

That size up to 2200mAh is common for upgraded cubs. mAh is irrelevant if adequate-that's only fuel amount. Only voltage and C-rating are an issue. Lots of help in the relevant forums.

The motor and ESC seem to max out in the mid/low-teens. PZ does not tell you so it is speculation and field experience.
A 3S with stock prop will pull almost 20A. It is NOT DESIGNED for that level. Most folks do OK if conservative and some are disappointed with burned components. A LOT depends on HOW you fly it and whether you prop down.

fly

[admiralev]

fly,

im serious about getting the cellpro this time . FMA direct has something new with it called revolution or something. is it still the same 4S charger you all love?

thanks

[flydiver]

No, there is a 10S (expensive-for BIG batteries).
Revoelectrix is their brand of lipos.
Special on the 3S 2100 for $39-not too shabby and a better battery than the cheapies. This one will not need an adapter for the 4S > plugs directly in.
www.fmadirect.com/Detail.htm?item=2210§ion=69

There is a special on the 4S also until the end of the month:
www.fmadirect.com/new_applications/monthly_special/monthly_special.html
Buy one, get one half off. Details on that page.
Now, if you can get someone to go in with you...

fly