shurcooL

I've been looking at the discharge graphs for PolyQuest batteries on enerland.com official site, and here's what it looks like for a single 4500mAh Lipo cell:


It seems like it kinda drops off at the end, although it has good punch (i.e. high voltage) during the first 20-30% of the pack.

I'm not sure how good that is compared to TrakPower 4900. I've seen the discharge graphs for the NeuEnergy cells and they seem to be much more flat... as in consistent throughout the discharge, right until the very end.
But the average voltage seems to be close to 3.5v in both cases.

P.S. Does anyone have a link to a similar discharge graph for the TrakPower 4900 25C pack? I'd be very curious to see it.

Stallard

Cool to see other carrying the polyquest packs.

I have had great luck out of my thunder power flight packs (Never used them in a car)

My guess for thunderpower was based on the fact that their 5000mah and 5100mah packs are rated the same but as I say just a guess.

You are correct flightpower and trakpower are the same company as for them using enerland cells I have heard that also but I would guess they are made to the specs flightpower requires but not nesissarily the same cells as polyquest.

SpeedKills25

I currently own 2 lipo packs. The team orion 3600 and a SMC 4000. I have about a dozen or so(maybe a lil more) runs on each and i have not balanced either packs since buying them. Am i running the risk of ruining my packs or is it possible that i can get away without balancing them for the duration of their life.? Are there any statistics on whether or not a balancer is necessary?

shurcooL

SpeedKills, I think it depends a lot on how far you push these batteries. What I mean is, if you use them to their 100%, which means using up about 80% of their rated mAh capacity, from fully charged at 4.2v per cell down to empty at 3.0v per cell. Then a balancer is probably highly recommended, as sooner or later, the cells will go even if slightly out of balance, and that means you will be pushing some cells past 4.2v when charging, and discharging others past 3.0v.

I guess that raises two questions. How much will the Lipos go out of balance if you don't balance them? And how sensitive are they to overcharge/overdischarge past 4.2/3.0v respectively. I think some are very sensitive, others may be less so. Either way, you are shortening their life... But it's unknown to me if that life loss is significant at all... or just from 300 cycles to 250 cycles.

That's the theory behind it, anyway. Unfortunately, for now that's all I can offer as I have no practical experience with Lipos at all. I just know stuff from what I've read around in the last couple months.

P.S. Personally, I got myself a charger with balance built in as I'd like to take best possible care about my future batteries. Especially seeing how they can easily blow up in your face if you mistreat them. >.>

Edit: I've heard that Team Orion boasts that their Lipo packs don't need to be balanced at all. Some scoff at that and say it will shorten their life. But perhaps the damage is not significant enough, otherwise why would they promote no balancing of their packs? It's possible their cells have more of a safety buffer and can go up to 4.25v and down to 2.9v, for example. Just a guess though.

d16dcoe45

iTrader: (1)

I notice you are getting the lipo for your B4. Even the big 5000 SMC fits fine in a b4. t4 and CR. The only thing you have to do is cut a half-moon out of the side of the battery tray to clear the wires coming out of the side, it takes like 2 minutes with a dremel and doesn't affect the chassis strength much at all.

This pack is amazing. Its worth it even with the wires coming out of the side.

SpeedKills25

Hey thanks a lot for your informative information. My mind feels more at ease now instead of worrying about damaging my packs. It is very rare for me to ever run my packs down to the 6.0V cut off point, so i guess i am doing something good for them. It's also good to know that my Orion pack may not need balancing at all. It seems the ones that are scoffing at orion for their claim that the packs need no balancing are the ones trying to sell the balancers. lol

Is it possible to overcharge my packs if i am using a charger that detects voltage and all? I own the Hyperion EOS5i and so far i have been very happy with it.

shurcooL

Np, glad I could be of help.

It's still possible, of course, because the charger only knows the total voltage. It won't know it, if one cell is at 4.23v and another at 4.15v, and will keep charging until their sum is 2 * 4.2 volts.

Do you have access to a voltmeter? What I would do is manually check the cell voltages after every 10 cycles or so and see if they differ by more than, say, 0.03-0.05v. Then you might have to worry about balancing them. Until then, it should be ok, but only because Team Orion swears by their packs not needing to be balanced. If it were any other, I think from what I've heard even a 0.02v difference is too much and should be balanced.

SpeedKills25

I don't have a voltmeter but maybe i should look into purchasing one. If i do get one, whereabouts would i hook it up to in order to get the readings? Maybe a voltmeter would be a cheaper alternative than purchasing a balancer as well as the adapters that i would need for each of my packs.

shurcooL

I wouldn't call voltmeter a cheaper alternative to a balancer, but it sure is handy having one around for all kinds of things, esp. when you're dealing with electric cars. It's probably good for other stuff around the house too.

Anyway, just be sure to set the correct mode (measure DC voltage, <20V) and carefully bring (so that you don't short circuit) the test leads to the individual pins on the balance plug on the battery.

Something like this:

shurcooL

An update about my first Lipo to be:

Ok, so perhaps I'm in a risk taking mood, but for whatever reason, I've decided to temp fate and go for the PQ-5000RXQ battery!



Sure does seem like I'll be one of the few people to try it out, haha.

Anyway, I'll see it here in about 1-2 weeks hopefully, which is more than enough time to finish my computer PSU -> 12v DC power supply conversion and figure out how to work my Lipo charger.

I'll definitely let you guys know how it went when it gets here.

P.S. Worst case scenario, if it turns out to be a major disappointment, I'll just say screw it and order a TrakPower 4900 lol. But I think that's unlikely, as just about any Lipo would be a HUGE improvement over my current 1-year-old Venom 3000 NiMH pack, heh.

wyd

iTrader: (51)

I have been running the Trakpower 4900 for 10 months now with my Castle 4600 and 5700 setups. All I can say is it works flawlessly with no drop in performance after all these months. Been running offroad with my GV2.

SpeedKills25

Do you use a cell balancer for your Trakpower?

wyd

iTrader: (51)

Yes I do balance them and I charge at 1C. I was using Trakpower balancer but now have switched the Hyperion DUO and the Hyperion Trakpower balancer. Biggest thing I noticed is that my charge times have dropped some by using the Hyperion setup with Hyperion balancer vs the trakpower balancer and charging with my Hyperion 5I.

SpeedKills25

I am thinking about purchasing the Polyquest balancer from RClipos. It's only $29.95 and the site also has every adapter you could think of for all Lipo packs. The total purchase with 2 adapters and the balancer will come to just over $40.00 which is not to bad.
In case any of you guy's are interested i just spotted the deal of a lifetime for the new Intellect 7.4V 3800 25C hardcase Lipo. $53.00 from rcmushroom. With shipping included it comes to about $70. That is a very good price for a lipo pack coming from a reputable company. Not to sound harsh, but i feel bad for the saps that are still buying Nimh cells.

ta_man

iTrader: (168)

It was mentioned recently, somewhere on RCTech, that using a balancer between your charger and battery will cause the switchover to CV (Constant Voltage) mode sooner than if you were not charging through a balancer. Reason given was that the balancer adds some resistance in line with the pack and so the charger sees a higher voltage than the actual pack voltage. With the Hyperion DUO, the charger sees actual pack/cell voltages since it is not charging through the balancer. So it doesn't switch to CV mode until later in the charge cycle (compared to an in-line balancer). I also notice my packs charge much faster with my Hyperion than with a different charger that goes through the in-line balancer.