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Dual Batteries?

Old 06-18-2005, 07:51 PM
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ICE_MAN
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Default Dual Batteries?

Hey guys,

Right now in My ultra Stick Lite I'm running 1 6 v. battery... I've been thinking of switching over to 2.. But How? I know 2 switches. But where do i plug the 2nd in? And What about the extra 6 volts.. Won't that fry my receiver?

Also What about Li-Ions? Are they reliable? pro's Cons?
Old 06-18-2005, 08:04 PM
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Default RE: Dual Batteries?


ORIGINAL: ICE_MAN

Hey guys,

Right now in My ultra Stick Lite I'm running 1 6 v. battery... I've been thinking of switching over to 2.. But How? I know 2 switches. But where do i plug the 2nd in? And What about the extra 6 volts.. Won't that fry my receiver?

Also What about Li-Ions? Are they reliable? pro's Cons?

Ice,

You can plug the second batt to any open channel on the receiver, but if you have no open channels then just use a Y connector. You will be running 6 volts in parallel so it's still only 6 volts. the main difference is MaH. Dual batts must have the same volts you cannot mix 4.8 and 6.0 but the MAH size can be different. I use 2 2700MaH Expert batts on my bigger planes and actually just ordered my first setup with LiPo from Fromenco which is Package priced at 201.00 but it comes with three LiPo batts, three reliaswitches and 3 regulators. I already use there switches and regulators but I wanted to switch to Lipo.

They have very good info on Lipo and charging. I will not need their charger as I have the Hobbico Elite that does LiPo LI-Ion but only does 2 at a time.

http://www.fromeco.org/Shop/shopdisp...5&cat=Packages
Old 06-18-2005, 08:14 PM
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RCKen
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Default RE: Dual Batteries?

Bubbagates nailed with his answer. Plug it into any empty channel slot on your receiver.

Ken
Old 06-18-2005, 08:43 PM
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Default RE: Dual Batteries?

[quote][Also What about Li-Ions? Are they reliable? pro's Cons?/quote]

I forgot to mention that htere are things with LiPo and Li-Ion that you must be aware of like overcharging them can cause them to start a fire stuff like that but my LiPo experience is lacking so I'll leave that up to someone more knowledgable.

I do know a few guys that run them in dual setups at 2400 and they usually go many many flights between recharges and seeing what they do on electric planes for powering brusheless motors then I would say it's worth the effort so that's why I ordered my setup
Old 06-18-2005, 09:40 PM
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Default RE: Dual Batteries?

Cool thanks guys!...

What do Lipo's weight compared to Ni-cds?
Old 06-18-2005, 09:48 PM
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Default RE: Dual Batteries?


ORIGINAL: ICE_MAN

Cool thanks guys!...

What do Lipo's weight compared to Ni-cds?

On average about half the weight for the same power
Old 06-19-2005, 03:46 AM
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Default RE: Dual Batteries?

The initial investment into Li-Ion batteries is a considerable amount. Remember you need a charger (Fromeco makes a great charger $120) and if your regulators are old you might consider new ones, Fromeco makes great regs...insurance against failures from old equipment.

1. Great weight savings over NiCads or NiMhs!

2. No significant discharge while they sit over time! As long as you unplug the regs if they are fail-safe.

3. Charge in a short period of time (i.e. 3 hours) normally.

4. Smaller size compared to the same mah NiMh or NiCad.

5. NO cycling, it's just not required.

I love Lithium batteries! I have them in 5 planes/helis and love them!
Old 06-20-2005, 04:09 PM
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Default RE: Dual Batteries?

Okay, let me return to the dual batteries wiring issue.

If we use two batteries would it be good to protect against one battery draining the other, for example: We set up battery to switch to receiver, and a second battery to a second switch to the same receiver. If the first circuit experiences a short, won't we lose power despite the second battery and switch? (I am no electric guru.)
To avoid that risk, could we install an appropriate diode in each circuit, to prevent draining both batteries in the event of a short in only one circuit?
Old 06-20-2005, 04:33 PM
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will
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Default RE: Dual Batteries?

All of your questions can be answered [link=http://www.rcbatteryclinic.com/]here[/link]

Pick your topic on the left and go from there.

Old 06-20-2005, 07:10 PM
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Default RE: Dual Batteries?

Will: Tks for the link...great site!

As I understand the information there: The battery packs are unlikely to short, and checking them before each flight should uncover any problem with either pack, hence, no diode is needed. However, if a short developed somewhere between the battery and the receiver, would that not only fry the pack in the shorted circuit, but also rapidly drain the second battery?
Old 06-21-2005, 01:24 AM
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Default RE: Dual Batteries?

The article you read said that most shorts occur and the battery "blows them out," meaning the battery would just quickly short and then cease to work at all. You would be flying on your other battery and probably not even notice the short until you checked your battery's capacity before your next flight (or right after you land).

The WORST case, if you had a "hard short" where there was the equivalent of a wire across the terminals you would cause the battery to melt down, fry itself and probably your receiver too...you wouldn't be worried so much about your other battery...

If you feel your controls getting mushy, or acting differently than they should, land immediately and investigate! You could have a low voltage condition or worse!

The article states that the "hard short" is extremely rare...read "worth taking the chance." Unless you FAST CHARGE your batteries right up against their limits, you probably won't ever have to worry about this "hard short" problem...I haven't seen it in 15 years of flying with NiCads...just switched to all Lithium BTW.

Wheels up!
Old 06-21-2005, 07:00 AM
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Default RE: Dual Batteries?

The AMA had a warning last year concerning Lithium batteries, care to be taken during charging. Perhaps that would be good for many people to review (take precautions) to avoid problems. They are great batteries but take a little more care than others do.
Old 06-21-2005, 06:52 PM
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Default RE: Dual Batteries?

ORIGINAL: FlyinTiger

The article you read said that most shorts occur and the battery "blows them out," meaning the battery would just quickly short and then cease to work at all. You would be flying on your other battery and probably not even notice the short until you checked your battery's capacity before your next flight (or right after you land).

I read the article differently: "Rarely does the short occur all at once but rather building up a very small conductance path termed "soft shorts". In a charged cell the energy in the cell will blow away any short as it tries to develop. You've heard about "zapping" cells. The cell actually zaps itself before the short can develop."

As I read the comments, a "soft" short is corrected by the the energy in the charged cell. The "soft short" is blown away, not the entire capacity of the battery, i.e., the battery would not cease to work at all.l
Old 06-22-2005, 09:59 AM
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Default RE: Dual Batteries?

I suppose we could have "soft shorts" all the time and just never notice them...even better, the Lithium battery is even more reliable than I thought. I still charge mine in a fire safe ceramic container and check their voltage after charging and before every flight. I always do a thorough preflight check on my planes and check the flight controls every time I set up my plane at the field, before the first flight of the day on the run-up and taxi out.

I trust Lithium batteries because I am careful, follow the directions, and then always double check my equipment...that is a good practice, especially in aviation.[8D]

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