LOL Post #445 from this thread.

LOL this is better then the meds. Post #451 This thread.

There is a fifth to but Nobody knows.

Well Slap me Backwards with prop wash. Is it Race or is it rec.

Whos the MBP around here? Flyboy? What happened to WL and Waz with those 123s?

MPT is just thinking off the shelf like me. If you have read this whole thread you know as much as me.

Race packs aint the same as sport packs. Flyboy says after 10 cycles race packs will no longer be matched and arent worth the extra cash.[to him] But he has the hardware and know how to keep his packs matched. Why does he like Side by side again? He is a MBP already. Ben is in there to. Thats two MBPs right there.[no lipos yet Ben] We could put together a killer Race Team if we wanted.

If ya try to race the sport pack its gonna heat it up. Those packs look good Jack, because they are matched but like Wheel said Tabs and wire gotta go.

Batts are to much work.[for Raceing][unless ya got a Batt putz in the pits] I just want to charge it and run it.[8D]

Problem is this boat is screaming for Amps.

So whats the Best sport pack to get?

Wo Mack..............back. Give me some slack and off the attack.
OK.....who slipped into Speederson's den and woke him?
You're gonna have alot more typing to do because there aren't just 5 dimensions. You have 6 more to go. You can't forget the String Theory?[8D]

Hey, it would have been nice to know about how matched packs lose their balance before posting that. We were once again graced by Funboyfly and Ryan with their exposes on matched packs losing their umpffffffff.

I agree, tabs and wire gotta go. That's why I had to ask about them. Even at $60 for 2 packs, wiser to verify. I can't bother with putzing......I mean putting packs together either.
Batts are too much work.[for Raceing][unless ya got a Batt putz in the pits] I just want to charge it and run it.
That's how you feel now because you haven't converted your hull into a Cutter.........Cutty Sark........Mr Subliminal.......
Truth is, once you thaw out and run her a few times, you'll be making changes to get more speed.

I think if we put together a race with all of us we would we need the following support:
1. 911 (triple play.......police for the scuffle, amby, and fire)
2. HAZMAT (hey.....new name for Benmat since he's running lipos.........BenHAZmat.
3. Cooler (up to the individuals)
4. 800# to Tower Hobbies or Aquacraft
5. Local News
6. Someone with a really big pool skimmer for getting the debris fields cleaned up.

I think if we put together a race with all of us we would we need the following support:
1. 911 (triple play.......police for the scuffle, amby, and fire)
2. HAZMAT (hey.....new name for Benmat since he's running lipos.........BenHAZmat.
3. Cooler (up to the individuals)
4. 800# to Tower Hobbies or Aquacraft
5. Local News
6. Someone with a really big pool skimmer for getting the debris fields cleaned up.

That's too funny!

Hay! How do ya change your name on this forum? I'll get some respeck with that name.

I thought you'd get a kick out of that one.
Click the "My Account" tab at the top of the page. Make sure you're in "General Profile", then next to the "User name" field click "Change".

Would you believe, that name is taken. They don't realize I'm a hazzard looking for a place to happen.

Ben

Thanks again for the help with Austin's 8c IB4200 race packs last night. He should really be flying now!

Don't rub it in. That kid ia a menace to the old folks at the pond. Let's add some weight to that boat.

Ben

Don't do that! He can already do some serious damage with that battleship if he decides to run us down!

Anyone using fine design "firefox" GP 3700 packs? these packs sound good for the price.Can the GP3700 cells take the same abuse as the 3300's ?

Hey benmat, you can always go for the name HAZbenmat.

I got my SV27 up to 70 mph today!

Too bad it was sitting on the front seat of my truck at the time.


Randy

Ok try not to rip me a new one to bad and check these out.

http://www.amondotech.com/index.asp?...OD&ProdID=1006

add a single one http://www.amondotech.com/index.asp?...OD&ProdID=1002 and for $125 ya got 3 sets[6 packs] plus a charger.
Ya I know plugs gotta go.

Speederson, I'll go easy on you this time. Hey, I thought I was gettin' the rippin'.
Not bad. Actually, that's a really good deal for people getting into the rc boats. Or, $200 and you'll have 2 chargers and 6 packs. Just need to find something to do c/10 charges. I think the 14awg wire will be sufficient, and, like you said, go Deans plugs.

The only thing I would question is the internal Ohms.....at <5 Ohms, that seems a bit high when comparing to the other packs I found, rated at 5 milliohms per cell.

[quote]ORIGINAL: Orange Crush

My SV27 has a tendency to capsize! I'm working on tuning it so it is more stable on the water.

Uhhh...what prop are you running and with what tab setting.....

"Capsize" means sinking.... Is it taking on water just sitting in the water, or do you mean it's taking on water when it flips???


actully capsize means flipping over upside down, and the act of returning the boat upright is called "righting"

sorry, old sailor, just coun't let it go

I have been using the Fine Design 3700 packs,,,,,they rock

Hey guys - I've done quite a bit of reading on this thread but the conversation is above me at some points. (Kinda like sitting in on a surgery). I've made boats go fast before and I know a few things about vehicle dynamics, but my power plant was a chevy small block.[>:] I'm kinda in the process of building my own FAQ for FE (working on batteries as they re my weakest point). If it's appropriate I'll share it and you guys can feel free to edit. These threads would be way more beneficial if the new reader had some basic knowledge of what was important. At this point it soaks in rather slow. That said let's start as square one for a second:

The 4 digit value on all batteries is the miliamp x hours the battery is capable of delivering. I understand this to be a combination of time vs power output. There are two things that everyone wants, long runtimes and high speeds. So the bigger the number the better for either, but typically the more of one the less of the other. Correct?

The way I understand it is that the best packs have the lowest resistance (meaning good quality cells (still trying to understand what that is) and they are tied together in a way to lower discharge resistance) IE good, thick wires, deans connectors, and bars replacing wire where possible.

I've read a great deal about battery care where I think the whole idea is to get all the cells even and to their max potential.

Also I see refrences to "getting them up to operating temp by topping them off. I assume this makes sure they are maxed out and also warm (does temperature speed the chemical reaction?)

That's all for my first swipe. Belive me, I'll have more.

Thanks.

Dayton,
The 4 digit value on all batteries is the miliamp x hours the battery is capable of delivering. I understand this to be a combination of time vs power output. There are two things that everyone wants, long runtimes and high speeds. So the bigger the number the better for either, but typically the more of one the less of the other. Correct?
Yes, in order to achieve longer run times (without using a smaller prop) we need more mAh. However, more mAh does not mean higher speeds. The reason, for instance, IB4200s are faster than say DTX3800s is probably due to the IBs being better all around cells, with lower internal impedance and construction. Usually, the higher the mAh, the more internal "resistance" you will have. The trick that OC found out was with the use of IB4200s, (having just the right amount of weight, punch, and least internal resistance). I'm sure there are other cells out there with similar mAh rating, but with lower internal impedance, but we don't want to spend bookoo $.

The way I understand it is that the best packs have the lowest resistance (meaning good quality cells (still trying to understand what that is) and they are tied together in a way to lower discharge resistance) IE good, thick wires, deans connectors, and bars replacing wire where possible. Yes, you got it. Also answered above too. The best cells will be balanced, basically meaning they all put out the same within the same time frame. The voltages b/w cells will be within say .03v of each other. Where as unbalanced cells might be w/in .07 of each other.

I've read a great deal about battery care where I think the whole idea is to get all the cells even and to their max potential.
As we've found found out from others, matched race packs are the best, however, they lose their balanced voltage b.w cells after about 10 or so cycles. Better off buying unmatched cells because we balance "form" them when we get them to begin with. We use the "C/10" charge for this and every month to "re-balance" them. Simply put, if you have 3800mAh packs, form charge them when you get them at .38A a couple times before you run them in the boat. Also do this about every 4 weeks.


Also I see refrences to "getting them up to operating temp by topping them off. I assume this makes sure they are maxed out and also warm (does temperature speed the chemical reaction?)
Grim led us onto this one. Top off the packs before racing by bringing the cells up to 120F, then run them as soon as possible. I think this agitates the chemical process, but it also will lower the overall operating temp of the cells while in use. When I run my CF48 and X645 prop, the batts are very close to a safe theshold of 145F. After using Grim's recommendation, the packs are about 5deg cooler.
There is also about a 2-3mph gain on the water. It is very noticable when you compare performance of packs prepped this way against ones that were charged the day before or even a few hours before racing. NiMh packs lose their stored charge fairly quick.
Repeak (more than once if necessary) them on race day to 120F using no more than about 2A and you will have better performance. The reason I say 2A (1A will be better, just takes longer.......I like 2A) is if you go higher, the more unecessary heat is produced in the packs and less mAh. I don't run my packs more than once on a race day, so I don't use the higher charges. And I'm not saying fast charging is bad, but when using higher charge rates, you try and cram more mAh in the packs at a faster pace. This means more heat and less mAh.

In most cases the higher the mAh the lower the battery internal resistance will be. Or the higher the discharge rate will be. But the displayed figure (mAh) is not particularly related to discharge current.

It only represents how much current can be passed in one hour of time. Of course you can apply a load of 0.1A on a battery for 10 hours and through a simple calculation the capacity is 1000mAh. This particlar battery may not be able to discharge over 100mA but still can output 1000mA in an hour.

Yes, as quality increases, internal resistance decreases. There are a ton of factors that contribute to the internal resistance of a battery. It could be quality of plates used or quality in the chemistry. Impurities in either case will increase resistance. The wires that connect the battery is also important but not as important as the actual cell quality itself.

Heat is not particularly desired when discharging/charging batteries. As heat increases, resistance increases. But the major concern here is cold batteries/cold weather will affect discharge performance.

To minimize this issue and maximize run time, top of your pack just before use.
When you charge batteries before using them it helps the catalyst to activate the chemical process. This in turn will warm up your batteries. This process may take 1-10 minutes depending on the cells, chemistry, charge.

Cold weather/batteries will slow the process down - better for storage

Ryan

"I don't run my packs more than once on a race day,..."

You should try it sometime. I get better performance on the second charge of the day even though I peaked to temp on the first charge...

I'll have to find a water hole that can allow me to get my vehicle closer and recharge them that way. The lake by my place is surrounded by a pretty steep depression. I pondered it a while ago, but then dropped the idea. It'll probably give me that extra speed I'm looking for. Maybe an alternative to getting more bang would be to cycle the packs through the Superbrain the day before......yikes, we all know how much a pain that would be, and it probably wouldn't be as beneficial compared to your recommendation. I'd also rather lose a cycle of the packs on the water having fun, than through the discharge function at home.

Thanks man (MBP). Another reason to try new water holes.

OC,
You raised (3) questions from recharging in-the-field.
1) What temp do let them cool back down to or how long do you wait before re-charging packs in-the-field?
1a) Do you still use the 120F rule when re-charging?
2) What charge rate do you use?
3) Probably insignificant, if you use 5-6A for the re-charge, is there a significant loss in drive duration? From like 7min down to 6 min?

Thanks

Now you know I'm not that analytical! I allow them to cool suffienciently to touch. I'd say 75-82 degrees. Keep in mind ambient has been below to well below 70 degrees here for sometime. The way benmat and I run, he takes a run, then I take a run, then he switches to his "cheaters" and takes a run and then I run the good ole IB's. Between the cycle and all the questions from onlookers, allowing some passing kids to play with our slow boats and the general bs sessions, we have plenty of time to cool and recharge.

If you remember, I'm a normal 3 amp charger, anyway. when I field charge, it will typically be at a 4 a rate.

I can't say I've ever really timed a complete run other than looking at the video length from "Turkey Day Run II". That was the second run that day....first and only run that day on the IB's. You know, I usually crack up long before the packs dive, anyway. (MCP)
I usually don't push the packs anyway. It seems he and I are mostly out for that "number" and we pretty much know when we've acheived the best, or at least when we know we no longer have the juice to do so....

The weather here has been so bad I haven't run much. I did an exibition of SV ability for a LHS owner who had just had a "prominent" (we all know him) FE guy rig a 33" mono that the LHS owner had designed and built with a Nemi 8XL. I let the guy borrow Austins 16 cell Gp3300's, too. We dragged 3 times for about 250'-300' and called it a draw at the end. I was pleased, he was both dissappointed AND amazed!!

Thanks guys! Great discussion. I'm glad I waited for you. Iwas beginning to get impatient. Now I realize that Black began his response (long, detailed response) imdiately after I posted on Tues. I appreciate the time you guys take. OC are your mods current on you "models"? You don't list the 42.6mph on there. Wondering what else you did. (2 turn fins?) did you scuff the bottom? Were you using GPS? I know wrong forum. sorry.