START HERE |
|
Register | FAQ | PM | Events | Groups | Blogs | Calendar | Mark Forums Read |
Unregistered
|
LiIon, LiPo, NiCd & NiMh General General Battery Support |
|
LinkBack | Thread Tools | Display Modes |
06-27-2015, 09:33 AM | #261 (permalink) |
Registered Users
Join Date: Feb 2015
|
Short answer: I would count on six batteries charged at 1C, not in parallel.
Long answer: Your math isn't wrong, it just isn't complete :-) When figuring out how much you can charge from a PSU or battery bank you need work in watts, then convert back to amps. Also, figuring out how much you can pull form a deep cycle is kind of complicated. Charging a 1300mAh battery at 1C needs 1.3A of current at a max voltage of 25.2V (6S * 4.2). Total power output from your charger would be 1.3A * 25.2V = 32.76W. Let's say your charger is 90% efficient so say 32.76W / 0.9 = 36.4W. You'll need a max 36.4W from your battery bank for however long it takes to charge your lipo at 1C. Let's estimate that at 45min. IIRC, that's about what a 1C charge takes for many people. BTW, I typically use this calculator to answer "how much power will PSU need to output". Once you put in your numbers, use the "PSU power" value to figure out what your battery bank has to give. That's the PSU in your case. OK, so now how much current do you need from your battery bank? You bank is two 12V batteries, so 24Volts. 36.4/24V = 1.52A. How long can you pull 1.52A from those batteries? As I said earlier, discharge rates of deep cycles are complicated, the less current you draw the more total amp-hours you get. I googled for that model number and found its spec sheet. According to the sheet, that battery will give 18Ah with a 0.9A current draw but only 15.30Ah with a 3.06A current draw. I usually use this calculator to figure out how many hours I can run a battery at a given load. Punching in the numbers for this battery, it looks like you could charge at 1.5h for a little over 5hrs (5h17m), before you hit the 50% safe discharge level recommended by that website. IIRC, Slyster says you can go lower. So, if charging one 1300mAh 6S lipos at 1C take 45min you could do 317min/45min = 7 batteries. In the calculations, I'm over and under estimating here and there. The actual performance you get will be different. Your charger will not need to output 32.76W for the entire 45min. Because the battery bank is 24V nominal, you'll actually pull less current (giving you more overall Amp-hours) from it. However, a few assumptions could swing this the other way. I assumed 90% efficiency in your charger, yours may be better or worse. Finally, charging in parallel or charging at more than 1C will require more current from your battery, which means you'll get less Ah out of it. If I was planning this for 1C, I would mentally "count" on 6 lipo charges. But, you should monitor battery bank voltage at the field and see what you get. Slyster's chart at the top of this thread says 24.2V for 50% and 23.6V for 30% DOD. Go down to 50%...or whatever Slyster says is safe. He has actual experience doing this. If you want to change the charge rate (2C or 3C) or go in parallel, you'll need to redo the calculations. Start from the first calculator, get "PSU power" in watts, divide by 24V to get current needed from your battery bank then put that amp number in the "Amperage of Load Applied" field of the batterystuff.com calculator I linked to above. |
Sponsored Links | |||
Advertisement |
|
07-01-2015, 08:40 AM | #262 (permalink) |
Registered Users
Join Date: Jan 2013
|
Charger Question
So what do the gurus think about this for a deep cycle charger-maintainer? Deltran Battery Tender Plus, part # 021-0156. Sorry for no link, not that computer literate. I actually bought two, one for a diesel tractor that I don't use in the winter and am tired of replacing the batteries every year or two and if I pick up another deep cycle I should be good to go.
Thanks |
07-02-2015, 06:33 AM | #263 (permalink) | |
Registered Users
Join Date: Dec 2009
|
Quote:
I am now running 24v deep cycle set up after reading about Slysters thread and lovin it! Here is the charger I am running.... http://www.ebay.com.au/itm/CTEK-MXT4...item43c5ed86c9
__________________
Goblin 380 iKon / Goblin 500 iKon Scorpion HKIII-4020-1100KV Spectrum DX9 308Duo / X6 Deep Cycle |
|
07-10-2015, 08:18 AM | #264 (permalink) |
Registered Users
Join Date: Jun 2006
|
Thank you for this thread. I'm moving to a 10S electric and it looks like this will work for me until I can get a generator.
For those of us no where near a Fleet Farm, can you recommend a battery that has lasted at least a couple of seasons and is commonly available - say, at an Autozone or Lowes etc? I plan on running 2 in series with a Noco Gen2.
__________________
Dave |
07-11-2015, 05:30 PM | #265 (permalink) |
Registered Users
Join Date: May 2012
|
I just went out to get something out of my trunk, my two deep cycles are charging. It sounded like they were bubbling . I had never heard them do this before, normal?
I'm using the Noco Gen 2 charger, that thing gets hot as hell as well. |
07-11-2015, 06:10 PM | #266 (permalink) |
Registered Users
Thread Starter
|
totally normal. thats why I open my windows a bit.. that (flammable) hydrogen outgassing and can explode... remember the Hindenburg?
__________________
"It's not just a hobby... it's a lifestyle" - Pete ϟ MINNESOTA! Goblin 500 + 700 / SK540 / Jives / DX8 / Quantum / RJX servos / 306b / Deep cycles |
07-11-2015, 06:17 PM | #267 (permalink) |
Registered Users
Join Date: May 2012
|
Yeah don't need my new garage blowing up, my wife would kill me!
Have to say the deep cycle setup is working fantastic! Me and a friend were both charging off it all day today. between the 2 of us we got 8 flights on the 600s and 12 on 450s/planks. Still had power left to charge more. |
07-27-2015, 07:19 AM | #268 (permalink) |
Registered Users
Join Date: Jul 2012
|
When using my 308 Duo to charge my deep cycle is there a "C" rating i need to go buy like we do with the lipos? Or can I just charge it at full 30 amps?
|
07-27-2015, 09:57 AM | #269 (permalink) | |
Registered Users
Join Date: Jan 2011
|
Quote:
http://instoresnow.walmart.com/artic...89967&id=60546 Most flooded batteries should be charged at no more than the "C/8" rate for any sustained period. While some battery manufacturers state a higher maximum charge rate, such as C/3, higher charge rates can result in high battery temperatures and/or excessive bubbling and loss of liquid. ("C/8" is the battery capacity at the 20-hour rate divided by 8. For a 220 AH battery, this would equal 26 Amps.)... Charging at 15.5 volts will give you a 100% charge on Lead-Acid batteries. Once the charging voltage reaches 2.583 volts per cell, charging should stop or be reduced to a trickle charge. Note that flooded batteries MUST bubble (gas) somewhat to insure a full charge, and to mix the electrolyte. Float voltage for Lead-Acid batteries should be about 2.15 to 2.23 volts per cell, or about 12.9-13.4 volts for a 12 volt battery. At higher temperatures (over 85 degrees F) this should be reduced to about 2.10 volts per cell. http://www.solar-electric.com/deep-c...q.html#Battery Charging |
|
07-27-2015, 03:35 PM | #270 (permalink) |
Registered Users
Thread Starter
|
Yeah.. that. Or just get an deep cycle charger!
__________________
"It's not just a hobby... it's a lifestyle" - Pete ϟ MINNESOTA! Goblin 500 + 700 / SK540 / Jives / DX8 / Quantum / RJX servos / 306b / Deep cycles |
07-27-2015, 10:14 PM | #271 (permalink) |
Registered Users
|
I use my pl6 to charge my SLA. Use for my car. Truck. And sled too!!
__________________
Dan Pesonen FBL, Don't think about it, DO IT. mCX2, nCPX, mCP X, Blade 400, MSH PRÔTOS, T-700N "Tri-Flow" I put that S*** on everything!" |
07-28-2015, 07:26 PM | #272 (permalink) |
Registered Users
Join Date: Jul 2012
|
both good points.....thanks.
|
08-02-2015, 06:02 AM | #273 (permalink) |
Registered Users
Join Date: Dec 2009
|
Check out cTEk have a great 24v set and forget charger.
__________________
Goblin 380 iKon / Goblin 500 iKon Scorpion HKIII-4020-1100KV Spectrum DX9 308Duo / X6 Deep Cycle |
08-13-2015, 04:00 AM | #274 (permalink) |
Registered Users
Join Date: Dec 2013
|
Thanks for posting this thread!
It has inspired me to build my own deep cycle configuration. So far I have done only charging case (https://www.helifreak.com/showthread.php?t=672304). Now it is time for something bigger as the preparation for 700. I had to buy a car for this as my current one was to small. I went for Toyota Land Cruiser HDJ-100. So far I have removed back seats so I have plenty of space behind. The good thing about this car is how it opens the trunk (it has additional room to place the model when opened). I want to attach deep cycles on the metal plate and attach this plate where the second raw of seats was mounted. I am preparing for the next season with the following setup: - 4 deep cycles 190Ah each, connected in 2S2P configuration This should give me 380Ah total capacity with 24V. In 90% of cases I consider discharge to 50%-70% and on occasions to 20% maximum. Capacity should be enough even for long day flying on 700 and small 24V 50W fridge for coke - Meanwell PB-1000-24 charger for deep cycles: http://www.meanwell.com/mw_search/PB...-1000-spec.pdf It is total plug & play, with 35A charging current. With this setup I will charge deep cycles with little less than 0.1C. I am just in the process of wiring AC in the garage. - Two Powerlab 8 chargers. I want to charge double 12S5000mAh battery packs with 3C by each charger, simultaneously. For this purpose I need around 800W on each charger. Chargers will draw around 80 amps from deep cycles. With that speed of discharge, the efficient capacity drops but not so much. Deep cycles discharge rate would peak to about 0.22C I am planning to have 4 12S5000mAh batteries and fly one when charging 2 others. 4 because I also want to give one of them rest after the flight. When I fly a lot, I usually fly every 10-12 min or so (3.5min flight, 3min heli & lipo handling, few other minutes for my brain relax+cooling motor&esc), and it should be enough for that. I have choosen PL8 not 306B because it gives 40A output current. This allows to charge 2*125000mAh in parallel with 2C each which is also a nice option to have (I can charge 2 * 12S5000mAh on one PL8 with 2C and e.g. 6 smaller packs with 3C for my small helis on another one)
__________________
Pawel TRex 450L / Protos Max v2 * 2 / DX9 / vControl / RF7.5 |
09-02-2015, 07:30 PM | #275 (permalink) |
Registered Users
Join Date: Dec 2012
|
I'm using one 12v deep cycle battery to power up an iCharger Duo 4010 to charge on one channel my trex 250 3s lipos and on the other my goblin 380 6s Lipo. While charging. The voltage on the DC battery dropped from 12.69v to 12.15v. 50% capacity. Is this normal? Will it damage the new deep charge battery? Do I need a 2 nd one to use it in series?
Any feedback will be greatly appreciated.
__________________
Mcx2, 2 nCPX 2 mCPX v2 2 130x trex 250 plus DFC 3gx mrs TREX 450L Dominator AR7200bx. Twin Goblins 380 Spirit flybarless DX8. I've purchase all my helis in pairs. |
09-02-2015, 07:44 PM | #276 (permalink) | |
Registered Users
Join Date: Jan 2011
|
Quote:
|
|
09-02-2015, 07:55 PM | #277 (permalink) |
Registered Users
Thread Starter
|
Always let the deep cycle rest a minute or two before measuring your deep cycle voltage to see how much capacity remains. With large packs (6s5000s etc) everything will run happier and cooler if you use two deep cycles in series for 24v input to the charger.
__________________
"It's not just a hobby... it's a lifestyle" - Pete ϟ MINNESOTA! Goblin 500 + 700 / SK540 / Jives / DX8 / Quantum / RJX servos / 306b / Deep cycles |
09-02-2015, 08:14 PM | #278 (permalink) |
Registered Users
Join Date: Dec 2012
|
Thanks Slyster. I bought the deep cycle after reading your post.
__________________
Mcx2, 2 nCPX 2 mCPX v2 2 130x trex 250 plus DFC 3gx mrs TREX 450L Dominator AR7200bx. Twin Goblins 380 Spirit flybarless DX8. I've purchase all my helis in pairs. |
09-02-2015, 08:51 PM | #280 (permalink) |
Registered Users
Thread Starter
|
Oh.. yeah I just say '6s' and ran with that.. yeah.. one deep is just fine! I am typically charging one or two 12s5000 stick packs so often use up to 60A output. Your good.
__________________
"It's not just a hobby... it's a lifestyle" - Pete ϟ MINNESOTA! Goblin 500 + 700 / SK540 / Jives / DX8 / Quantum / RJX servos / 306b / Deep cycles |
Thread Tools | |
Display Modes | |
|
|