RE: Hobbyking no customer service?
If you pay bottom dollar should at least RECIEVE bottom dollar stuff. You (should) GET what you pay for!!!! (even if it is cheap and not as good quality!)
Posted on: 2/28/2012 10:44 AM by Author "drumduan" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=10980133

RE: lipo storage
"It is simply a low limit to protect the battery, nothing more." Quoting your reply the low voltage cut off does protect the battery? Regardless I do not use a low voltage cut off as i find voltage sag prematurely cuts power. I routinely fly down to 3.5v per cell using 3cell hobbyking batteries. I have one that is 2yrs old and flight time are not noticeably shorter, and HK stuff is not exactly quality so I think 3.5v per cell is fine?
Posted on: 2/24/2012 11:12 AM by Author "drumduan" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=10974032

RE: NiMh help
2000mah is how much energy is stored in it. 2000mah is 2amps. By definition that battery could deliver 2amps, constantly, for 1hour. So if your set up uses 20amps at full throttle you could full throttle for 2/20th of an hour (60mins/20 = 3mins. 3x2=6min flight time). In reality this would be slightly less due to mechanical inefficiencies and the fact that the higher the amp draw the less efficient but that is more than enough detail for now?! 1C means 1xcapacitiy of the battery. So a nimh can be charged at about 1C, so a 2000mah pack can be charged at 2amps taking about an hour to charge. A 2000mah lipo that can be charged at 2C would be charged at 4amps and take 30mins. 1C = 1hr to charge, 2C = 30mins to charge, 3C= 20mins to charge, 4C= 15mins to charge etc. It is best to charge batteries almost as slowly as you have time for (too slow a rate and it will never charge fully, too fast and you will never be allowed inside again!!) So, 1C for your 2000mah nimh would be charge it at max of 2amps. If you have more than an hour to spare I would charge at 1/2C which is.....................1amp and it should take 2hrs.
Posted on: 2/24/2012 11:09 AM by Author "drumduan" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=10974024

RE: NiMh help
I would go for 1C.....
Posted on: 2/23/2012 10:59 AM by Author "drumduan" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=10972355

RE: Charge help!
so two 6000mah gives 12000mah. charged at 7200mah (7.2amps) would give a charge time of 12000/7200 of 1.6 hours, about 1hr 40, maybe more as balancing and amp drops off. If you charge one at a time it would be 6000mah/10000mah= .6hrs so 1.2 hours for both or a bit more for balancing. Looks like you are better off charging one at a time unless you take more than about 30mins to swap batteries around. Just noticed you can only charge your batteries at 1C (by definition an hour). So charging one at a time would be 2hrs (assuming 0mins turn around time between batteries). Charging both at the same time would be 12000mah/6=2hrs so the same?! I am quite prepared to be wrong as I am no expert!!
Posted on: 2/22/2012 10:58 AM by Author "drumduan" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=10970830

RE: New lipe battery and charger.....questions.....
Good stuff, just check the voltage and dont let it drop below 3.1v per cell. All the best
Posted on: 2/21/2012 2:33 PM by Author "drumduan" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=10969620

RE: Micro Battery Question
Think you answered your own question! You should not store fully charged (store at 70% max voltage- do this by setting voltage cut off on the charger or use storage mode if you have) then top off the night before flying. You should not use more than 70-80% of the capacity- maybe use a low voltage alarm in the plane, or get a feel for performance/time and stop then. The low voltage alarms sometimes go off prematurely because of voltage sag during heavy throttle use.
Posted on: 2/21/2012 12:00 PM by Author "drumduan" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=10969358

RE: trying to understand C
You may be surprised that I do know this. So you are saying I should believe a manual if the retailer gives it to me but not believe the manual if someone from the marketing/hype dept. gives it to me? With this day and age, google and interweb, it is difficult to know where the (dis)information comes from. You shouldn't believe everything you read, now you know, you're welcome!
Posted on: 2/21/2012 11:57 AM by Author "drumduan" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=10969352

RE: Where to buy least expensive quality Lipo batteries?
No and no for breaking in lipos and brushless motors. I am sure others will have an opinion? (happy to be corrected but it wont change my practice as the above has NEVER thrown up any problems! But I do embrace the variety of answers on here, its up the individual to apply all the responses to their needs, budget etc) Happy flying
Posted on: 2/18/2012 3:51 AM by Author "drumduan" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=10964225

RE: trying to understand C
I think higher C rating batteries can also be charged at a higher rate (amps) if your charger can deliver the power they can be charged faster. Batteries tend to have their own charge C rating (typically 1C so by definition about an hour to charge) but more are coming out with say 8C so 60/8 = about 8min charge time if your charger can deliver 8C (24amps for a 3000mah pack!) Good luck
Posted on: 2/17/2012 1:32 PM by Author "drumduan" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=10963515

RE: Lipo charge rates
no worries, No need to connect when fast charging (not balancing). Most agree to balance every 5-10times but if you have the time do it every time! All the best
Posted on: 2/16/2012 1:43 AM by Author "drumduan" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=10961279

RE: Adding caps to esc???
Thanks Von Bain. I am really at the mercy of everyone out there as I wouldn't even know how to start solving this problem. I thought the battery wires are to be kept short to reduce resistance as the voltage is always greater between battery and ESC compared to ESC and motor? Again not a statement just what I have picked up?.........Cheers
Posted on: 2/14/2012 1:58 PM by Author "drumduan" in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=10958945

RE: Where to buy least expensive quality Lipo batteries?
I have heard horror stories about hobbyking but I have been lucky. I think say $10 for 100cycles is better than $60 for say 500 cycles, also having more cheap batteries means you can charge them slower and take heaps to the flying field. Works for me!
Posted on: 2/13/2012 8:22 AM by Author "drumduan" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=10956849

RE: 12v starter Lipo battery?
I do tend to agree (results being what matters, not the maths) however.... The lawnmower battery (?Pb) will drop its voltage under load a lot more than the lipo so that could account some of the difference. Also a bigger battery can give more power- splitting hairs I know but it is important sometimes (you can smoke a smaller mah lipo of the same C rating than a higher mah lipo because the higher mah can deliver more amps).
Posted on: 2/2/2012 7:18 AM by Author "drumduan" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=10940057

RE: 12v starter Lipo battery?
Very sadly I do not have a gasser! I put a question mark after the "statement" because you can't hear inflections in text, it was a question not a statement so I wasn't saying it would work. "I use 2 of these on my cheap hobbico 90 starter. Most of the starters you can run up to 24 volts for the extra cranking power. My setup fully charged is about 22 volts. Using a bigger MaxAmps.com for all your LiPo, NiMh and NiCd RC Battery Needs. Click here now. battery with the same volts will not get you extra torque but it will last longer" A "bigger" battery with the same volts can give more power. I have an 11.1v 2000mah lipo rated at 20C, so it can give me 11.1v x(2000mah x 20) = 444watts. If I use an 11.1v 3000mah lipo rated at 20C I can get 666watts out of my power system. That's 30% more power with the same voltage but an increase in the available amps. I appreciate when using a starter to use these amps you may need to change the gearing rather than simply changing a prop but it still stands that you can get more power from a bigger battery with the same volts.
Posted on: 2/2/2012 6:50 AM by Author "drumduan" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=10940017

RE: New guy needs help with chargers
what size of plane do you have/want? The first suggested charger (50w) would be fine for smallish- say .25 glow size planes or 11.1v lipos. However if much larger the charger will take longer to charge 4cell larger capacity packs.
Posted on: 2/2/2012 12:51 AM by Author "drumduan" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=10939746

RE: charger help.
Yes, they are good. I meant to say lipos are worth it, not with it! Basically they need some care. You should never discharge them below a certain voltage (think its 3.4v per cell but double check that) otherwise you can permenantly damage them- many use a low voltage cut off alarm between the battery and esc unless the esc can be programmed. They also should be watched carefully during charging.
Posted on: 1/30/2012 2:19 AM by Author "drumduan" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=10934646

RE: 12v starter Lipo battery?
hey scotty, the brilliance is the simplicity- 5mins tinkering time and you will have a more portable, more powerful, more compact, more reliable etc etc starter! Not sure what the amp draw on a starter is but if you need to replace the lipo I think you could get a cheaper lower C and or mah one. Party on,
Posted on: 1/25/2012 2:00 PM by Author "drumduan" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=10927398

RE: Triple AAA NiMh Packs
I think LiFe are heavier? I think trying to save weight with lighter receiver battery is false economy- as a percentage of the plane's weight it is not a lot. So ultimately you are trying to save a bit of not a lot!!? Combined with minimal weight saving is a real increase in the risk of a ruined plane. Just my thoughts, I would try to build the plane lighter in other ways?!
Posted on: 1/24/2012 1:41 PM by Author "drumduan" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=10925577

RE: Northstar mods - Tell me what you think
I intend to use a brushless OS equivelant to a 55. The weight of a LiFe, the OS 55 BRUSHLESS equivelant and nose weight is less than the weight of fuel, .55 and weight in the nose (I wont need to add weight to the nose because the LiFe will go in the nose). Basically because i wont use nose lead the brushless power system comes out lighter. I will actually be reducing the weight in the tail because the elevator servo weighs less than 8oz of fuel. Because it will be electric and not glow where should/would i save weight? I.e. lightening holes. Regarding a relief hole in the wing, I have packed the plans away for the moment, I assume that the relief slot is infront of the TE wing spar?
Posted on: 1/23/2012 8:22 AM by Author "drumduan" in the forum "Seaplanes"
http://www.rcuniverse.com/forum/fb.asp?m=10923089

RE: Northstar mods - Tell me what you think
Sorry to restart this thread.... I have just aquired a kit from balsa usa and am thinking of going brushless with it. The combined weight of brushless and LiFe is more than a .46 and fuel however as I can place the battery in the nose I hope to come in under the weight or on it. Thinking of the weight where on a brushless version could/should I save weight as compared to the glow plans? In addition I intend to place the elevator servo in the motor pod, the throttle cable obviously wont be a concern! I want to use a 13" prop and as such need to increase the height of the motor pod. By doing this the moment arm will be increased thereby exaggerating the tendancy to nose down with throttle inputs. Will this be a problem? If so should I increase the downthrust to compensate? Or reduce the distance from the LE of the motor pod to the TE of the wing in an effort to reduce the moment/torque applied by the motor? Thanks
Posted on: 1/23/2012 6:33 AM by Author "drumduan" in the forum "Seaplanes"
http://www.rcuniverse.com/forum/fb.asp?m=10922946