charging batteries
 

I have a 600mah pack that came with my radio/flight pack. I can get 3-4 flights out of it before my voltage starts dropping too low (my instructor says he doesn't like to fly with the volts below 5.0) and my instructor says its time to pack it up. I figure I have 2 options to get more flights in when I go fly. First is to buy a higher mah battery pack. The second is to invest in a charger, which I figure I'll eventually want to do anyway.

I have an old peak charger that I used to use when I was racing off road electric cars. It can range 0.5 to 10 amps and the manual says I can use it with a 4cell pack if I use the the dropping resistor.

Can I use my old car charger? what settings do I need to use. If not I'd like some recommendations for a good economical charger

Thanks

RE: charging batteries
 

I use the apache 2030, which i believe is an excellent value. I got it on sale for 30 bucks form hobby-lobby and it can charge 1-8 cell nicds/nimhs (A standard receiver pack has only 4 cells), and 1-3 cell lipos. I think its a great starter charger for the hobby. It certainly kept me on the field for a longer time!

Good luck

Samolot

Link: http://www.hobby-lobby.com/chargers_lipoly.htm (its the third one)

RE: charging batteries
 

Should be fine....charge at 1c or .6 A, but in this case, .5 A since that is the closest setting. Be sure to trickle-charge the battery after you get home. Peak chargers are like 'battery-hammers', they work, but they don't work well.

Invest in some higher capacity batteries when you move on from the trainer. The 600 mah pack will be fine till then.

When you are ready to invest in a good charger, I like the Triton I got a year ago, but there are better ones available. MAKE SURE YOU GET ONE THAT WILL CHARGE LI-POS, NiMH, NiCD and if you want, Li-Ion.

RE: charging batteries
 

Neddy,

I really like peak chargers. I also like higher capacity (say Nickle-Metal Hydride) batteries. However, part of the problem can be solved by reading and learning about the batteries. After you have soloed, you will be able to fly a lot longer because you will no longer have the instructor stopping you before the battery gets down to its Nominal or Standard voltage.

There are many days that I start flying at 5.0 volts. Stopping when the battery drops below 4.8 is a conservative approach.

Makes no sense to stop at 5.0 volts.

Sorry, that is about as polite as I can say it.

Ken, AMA 19352

RE: charging batteries
 

I have been building and flying since 1984 and struggled to understand battery technology for sometime, until I went to a pylon race. I noticed that 98% of the racers were using a Sirius Peak charger. I brought one and I have never been dissappointed. I now build my own packs using both nicads and nihms, and the Sirius handles them effortlessly. I just plug em in and go.

RE: charging batteries
 

I run the 600mAh batteries in my LT40 and controller... I throw them on charge everytime between flights - just takes a few seconds and I have no worries.

FWIW - I'm using a Hobbico Quick Field DC Charger MKII 12 Volt along with a Hobbico TorqMaster LC 12V 7Amp Battery . Picked up the wall charger for the 12V battery as well as charging leads for my radio and Rx battery. The money spent on this gear is near that which I'd spend on the high capacity batteries. I'll get the higher cap batteries down the road but this works great for now.

My 2¢... worth around 0.5¢. :D

somegeek

RE: charging batteries
 

Yup, what he said. There is little reason to stop at 5.0. It sounds like he's overly conservative. You can get good information on batteries from the R/C Battery Clinic: http://www.rcbatteryclinic.com/ .

RE: charging batteries
 

Neddy,
You should not let your pack drop below 1 volt per battery.
If this is the most common 4 cell pack, you've got one more volt to go.
Additionally, each cell is rated at 1.25 volts or 5.0 volts for a 4 cell pack, 6.25 for a five cell.
Why quit when you just got to the rated voltage, plenty of room left.
Good Luck,
KW_Counter

RE: charging batteries
 

Most NiCd batteries show their rated voltage for about 80% of the time it takes them to go below that rated voltage.

In other words, your instructor is telling you to stop flying when you've probably only used 20% of the battery. If he is a good flying instructor, kewl. But you need to find someone else to learn the other details about our hobby.

RE: charging batteries
 

Looking at an ESV reading of a pack isn't really the way to tell how much time is left in the pack. About the only value of that reading is to discover when the pack has dropped too low to fly.

The NiCd packs provide good power up until their last 15-10%. Then they show voltage UNDER their rating. When they go, they go fast. Until then, they show good. They show good with 75% remaining and with 20% remaining. So their showing a good voltage only means they haven't obviously given out. It shows nothing about how much is left.

What we have to do with our packs is test and record and figure, in order to fly safely. You have to have a charger that will tell you how many mAh it just put into your used pack. Without that info, you're pretty much in the dark. And your ESV readings will be all you got, and all they'll give you is a warning that it's already time to quit.

Go fly a fully charged pack. Fly 3 or 4 "normal" flights.
Put the battery on a charger and fill it up. See how much capacity went into that fillup charge.
Divide that capacity by the number of normal flights you flew.
Now you've got an idea how many you could have flown.

Lets say you have a 600mAh pack. Charge it to 100%.
Go fly 3 flights.
If your charger says it took 300mAh to bring it back to 100%, then you could have flown 6 flights total, but the last one would have probably ended with the "lawn dart" maneuver. So your pack would be somewhat safe for 5 normal flights and nicely safe for 4 flights a session. Had you looked at your ESV after the first flight of that example, your instructor would have told you to pack it in. Had you looked at the ESV after every one of your 6 flights, the last look may or may not have warned you off that 6th flight.

ESVs aren't really great insurance. Good insurance. But not enough. Test and figure and you'll be lots safer.

RE: charging batteries
 

If you want one of my club mates opinion, the Ice charger is the best. http://www.duratrax.com/caraccys/dtxp4170.html
Its like a mini computer, but affordable. It charger everything + memorizes batteries. ITs like a computer transmitter.

RE: charging batteries
 

agreed i dont recharge untill my 4.8v batteries go below 4.8. they will stay at the rated voltage(4.8v) for a several flights. but once it goes to 4.7 it will start to drop off quickly.