Waterlogged

http://www.rcuvideos.com/view_video....8d46f3b2027115

Here's what the new Elite4500 NiMH batts look like. Trim was set to push the nose down for stability. This is also on worked Prather 220 Bronze 2-blade prop. Turning was awesome, up on plane almost instantly, what the prop gives up in 1-2mph is gained by handling out of the hole. Motor and batteries were very warm after 2min 140F each! I did not run them out, took only 2400mah out of them to let them cool down. No sense hitting them hard at these power settings the 1st time out. These batts will wake up after more use, but damn! 65A new at 18.3V

And 935watts at 68A!!!!!!!!! Nice batteries and only the first run. Watt's Up is hooked to 1 battery, not both, so have to 2x the 468watts and 9.15volts =68A 18.3v.

Waterlogged

http://www.rumrunnerracing.com/fefor...ad.php?t=19121

Cell care info:

#6 09-19-2006, 10:35 PM
Ragged Edge
Drive it like its stolen

Join Date: Jul 2002
Location: Anchorage, Alaska
Posts: 369

Jim, The method Jay discribed above is the way many of use care for our cells, myself included. I would add a few things to Jays post. Every once in a while re-balance the packs with the low amp charge or if you store them for a period of time. Cells have a different charge/discharge rate while in use. The discharge rate also varies from cell to cell when the packs are not in use. So if you don`t run them for a while take the time to balance them before you thump them with mega amps.

As far as charging them to 7.2 volts, if you have a peak detecting charger it will take care of that for you. If your charger is not a peak detect charger then you can monitor the voltage until you see it start dropping, at this point you will notice the temperature off the cells will start to rise. 120 degrees is a fairly common point to remove them from the charger but many of use go as high as 140 degrees. After you have balanced your cells and ran them, allow them to cool before charging. Now charge them at the amp rating of your choice and when they peak out note the peak voltage of the packs, you will notice that the longer you use them and they start to degrade the peak voltage will begin to go up. Higher peak voltage is not a good thing, in most cases it is a sign the cells are begining to go down hill. Your pack that peaks at the lowest voltage is you best pack.

Another note on balancing your packs: it will not hurt to repeak the packs several times with a low amp charge as long as you don`t overheat the cells. I normally repeak mine several times until the temperature of each cell is the same. I check the temperature with a Raytec infared themometer. This insures that the cells are as close to being balanced as possible. It is much like the slow chargers of years gone by or overnight chargers used for charging your transmitter and reciever packs, you can leave them charging all the time if you want. The key to not damaging the cells is low amps and low heat build up in the cells.

Also Jim as Philip said, no mater how much fun you`re having, don`t overdischarge your packs. This is not a good thing!
__________________
Stupid people shouldn`t breed.

Tim

Blackjack52

That makes alot of sense. Never understood about cramming in mega amps all at once vice 1.5/2.0A charge rate. Oh well. I know I'm getting 5700mAh in my 4500s and 4600 in my 3800s. I can't get even close to those numbers using above 3.5A charge rate.
I'd much rather take my 5 packs to the lake, run them and call it a day instead of force feeding another pack. It would be more advantageous in the long run to buy another pack and keep charging it 2A than to charge at 5/6A every time.

This article just backs that up. But I do know there are differences about niMh liking to get really warm when charging. But this doesn't make too much sense either because the hotter the pack gets, the more resistance, thus less mAh, and less performance/run time on the water. Which again, is backed up by this article.

Waterlogged

oops, double posted

poe

Hey, im hoping some of you can help me out. Me and my dad are expenting 2 boats under the tree. I have been looking at the aquajet and supervee. Adviously the supervee is faster, and look like much better value and quality. What batteries work well in this boat? Will cheap ebay batterys work? How long are runtimes with 3000mah batts? Do you need a Y harness or just the batts? What is a good battery with runtime performance and value? Thanks
O yeah does this hull take chop nicely? will it flip easily?

Blackjack52

Has anyone charged their NiMh batts the night prior to racing, then "top off" the packs the following morning before hitting the water?

Will this destroy the cells over time?

Thanks

Wheelnut

My Feedback: (81)

I have done it that way many times and I don't believe it will destroy them over time because doing it that way has never hurt mine. I store my NIMH batteries fully charged anyway.

Blackjack52

Thanks. I wanted a little back-up before attempting. I also just found this on another site from Larry (Mr Truckpull). Sounds simple and seems like it would improve life.

Here is the info I got from our battery supplier.

Store charged

Every 3 to 4 weeks, charge at 1/10 C
0.38amp for 3800’s
to keep batteries at full charge and balanced (equalized)
At this low amperage any cell in the pack that is already
fully charged will dissipate the extra charge as heat and not hurt the cell.
This way you can guarantee that each cell in a pack is fully
Charged.

A day or two before a race I peek them once at 4 Amps
Discharge at 30 Amps for 2 mins.
Cool down
Charge at 3.5 Amps until peek.

For first race, I peek at 4.5Amps
sometimes twice to get 100F to 110F

After race day.
Peek at 1C, - 3.8 Amps
Store at inside house temperature.

Equalize batteries at 1/10 C every 3 to 4 weeks.
These cells will lose a bit over time, some cells more then others,
this is why you must equalize them to full charge of each cell.

Larry

PS- The first charge after you build a battery pack should be
1/10 charge to EQUALIZE the cells at full charge.

Waterlogged

Go with the 3800-4500 capacity batteries, they will give longer run times as well handle the amps much better than low-priced bargin batteries. I would rather have 2 sets of quality over 3 sets of El'cheapo any day. The 14c-4500's I built myself were $90 total from Cheapbatterypacks.com, good guys there and not 'cheap' on quality just a damn good deal.... Besides, making your own packs is so easy to do and they will take a beating, you'll have pride in knowing your equipment.

The assembled 6-7c packs you'll find online for under $40 ea will have welded straps most likely and we've seen a few cases of burnt shrink wrap ... Huh guys? .
All this Batt talk makes me want more, There, just ordered another set of 4500's from CBP.com WOOT!!! R-R-R I love these batts.
$40.44 per 6c-4500 w/Deans connector assembled.

Packs are your fuel and no skimping there.... well, no need for Matched Team packs for sure $$$ you'll not notice the difference for 2x$ anyway.
Budget $65-85 per set. Sounds expensive I suppose, 2 SV's x 2 sets== @ $300 in batts but they will last 200-400 runs if you take care of them. I was lucky myself, the wife said I didn't have to treat her to the monthly OutBack steak dinner and bought another set of Batts muahahahha See pics (before/after)

Charger wise, A Triton2 or TritonJr. will work wonders. I use an Astroflite 112D that charge/discharge up to 6 packs at once at 50ma-8Amps..... $130. This charger works great for Balancing too, just set it for 250mah and it'll top them all off w/o heating.

...This all sound pretty normal guys?...

I'm taking my 14c pack down to a 12c, making another 12c from the new order. I believe that 14c-4500's are too hot for the stock motor and my fav 220 prop, betting with trim and the 5oz less weight it'll go darn near the same speed as hot running 14c.....

-WL

Stinger9d9

I'm looking into chargers, and my main question is, what it the main functional difference between the Astroflight 112d and the Triton 2?

Other than the optional temp gauge for the Triton, what makes it better, or is it better at all?

I'll be using separate discharge/balancing trays for the batteries one which draws 20A, and another which draws 30A, so the discharge rates on these chargers isn't really a factor.

I've seen rebaged versions of many chargers including the Duratrax ICE, and Triton sold by other companies, which makes me think that they are all made in quantity by the lowest bidder, and sold worldwide by multiple companies. I have never seen Astroflight stuff rebadged and sold by anyone else.

Waterlogged

Triton2= All battery types but less cell count (but perfect for SV 4 packs at a time)
Astro 112D= Higher cell count but Nicad/NiMH only but very very easy to use and has a 10hour shutoff timer.

Only reason I ended up with an Astro112D was it was in stock

I would rather had 2x Triton2's. But still like the Astro. Still will get a Triton2 under the tree. -WL

Waterlogged

Elite 14c-EL4500's 5th charge.

6Amps until 4000mah, then dropped to 2A until peaked.

-WL

Blackjack52

Is that enough time to let the heat dissipate before going from 6A down to 2A? What kind of temps are you getting at 6A? Over 120?

Waterlogged

I slowed the charge current to 2A from 6amps just to use it llike a balance step in the charge. [:-]

I just finished balancing the 14c pack at 2A a little bit ago..... The 3rd cell in one of the 7c packs was at 1.31volts and 140F. The other 13 cells were all 1.42-1.43volts and less than 118F. I think this cell will have to play a different role, but not in this SV.

I took the 3rd cell out and currently cycling a new cell to replace it with. I had 10 new cells waiting to be assembled but glad I didn't. I'll have to order 5 more to make sure I can make a 2nd set of 14cell packs.

I'm going to use the bad cell for a glow starter batt I suppose. Not sure if the 68A run I pulled out of that pack on its 1st run killed a cell, was only like 2min but packs didn't really seem hot.


-WL

Blackjack52

Good thing you caught that batt. China Syndrome on the water.......not good.

I was thinking a slower charge would be better for balancing? Just curious. Also, if pre-balancing (at such a high rate), wouldn't it be better to let them cool before going from the 6A cycle?

Waterlogged

Ya, was trying to see what would happen if I used a balance step in the charge, but since pack was already warm, may have been little use.

I like the idea of charging the packs the night before going to the pond, and then balancing the pack at 2amps just before I head out the door for the pond.

-WL

Blackjack52

The cycle I'm using seems to be working quite well.

Store for the week in a charged state after done racing. Charge at 3A.
Day before racing, repeak at 1A. I did a discharge on 2 3800 packs for a control.
Day of racing, repeak at 2A to 110deg. The orig post recommends 120deg. Too hot for me right now.
All packs seemed to give equal performance on race day. Big difference was not having to go through the huge charge cycle the day before racing.

NiMh batts should also be stored with a charge.

I'm testing again this week to see if it's a constant.

The cycling I posted earlier in this thread is just too complex to keep up with. This one is much simpler and has provided, so far, good results, better than the way I was doing it.

Waterlogged

I had no real way of discharging cells so, I had to make one. $10 for 10 1157 auto taillight bulbs and a $6 computer fan. Plus Deans plug comes to $20

Discharges 1cell at 18Amps (24W) and 12cells at 28Amps (350W). Was temp'd out at 120F halfway through the discharging. The WattsUp meter gives the data.

-WL

1) Discharge unit
2) Discharging 12cGP3300's @350W
3) Discharging 1cEL4500 @24W

Blackjack52

I've read alot about people messing up batteries discharging that way. NiMh don't like that.

Waterlogged

Woah! Really. I'll have to look into it. Thanks for the heads up NiMH like pulsed rated? I have an old Astroflight speed controller I can connect to it and it'll run it at 4000Hz.

Thanks, glad you said something.

-WL

Stinger9d9

It would be better to use a discharge board, that way you don't risk cell reversal. Also, it balances each cell to an indentical state of discharge.

I picked up an Integy Octane 2 off Ebay for $12.50. It discharges each individual cell at 20amps, and you can drain each cell down to 0.0 volts depending on how long you keep the packs on it.

Better still, I got a BRAND NEW Integy Zero Thirty (30 amp discharge) for only $0.99.

Yeah 99 cents! That was the starting bid, and nobody bid against me.

Now I can safely, and quickly discharge two packs at a time, get all 12 cells down to the exact same voltage, and then charge them all at one, so each cell gets the same charge.

Waterlogged

GOOD info guys =)

Looking to see if I can find one.

Waterlogged

I see a lot of chatter about the harm you can do to your NiMH batteries if going below 0.9v/cell. I was using my Watts Up meter and manually disconnected the discharger when the 6cell 4500 hit 5.4V.

I'll plan on a safer 1.0v/cell when I manually discharge them. Also, seen a few places where high resistance discharging (bulb discharging) over 10 minutes will over heat the packs. So, same deal with staying at/below 120F I'm thinking.

Since I have both a Watts Up and a temp gun I'm fairly sure I'll be ok on my small scale of stuff. Which brings up the fact I had been using the Astroflite 112D to discharge the packs.... That may be where I killed that bad cell. The Astro 112D says 0.9v/cell.... But when it's on a 14c pack, sounds like 1-2 cells could drop so low [X(] Damn.

I'll see what I get for peak this 6th charge.... starting it in a min.

Waterlogged

Just discharged the other 7c-EL4500's down to 7volts (1v/cell) and got 11:30 time, 4001mah AND, funny number but... 120F. Seems like I've heard of that number before on pack heat.

The reassembled 7c-EL4500 with new (3cycles) cell installed. Before, that pack was peaking at 10.19volts and 5053mah..... Got about 90min left on charging.

Charging it at 3A like the side of the battery says is 'normal' rate. 6A Fast rate.

[sm=spinnyeyes.gif] insert time warp

The repaired pack went from 10.19v to 10.47v... Much, much better with the replaced cell.

-WL

Blackjack52

With new cells, you should be getting at least 5600mAh on the 4500s.