Battery charging question

Hi all,

Thanks for the responses to my previous inquiry. They were very helpful!

Incidentally, am currently assembling an electric powered glider by OK Models, called the "Caraway" (can be seen in the link below)

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The few question I have, though is generic, and not particular to this model.

I am using NiCad cells. There is a motor speed controller which the battery pack connects to. I must solder a connector to the battery pack as it came only with wire leads. My question is regarding charging this battery pack. Do you usually disconnect the battery from the plane's electronics before charging? If so, are these white nylon connectors the most convenient with respect to connecting/disconnecting repeatedly for recharging. What I'm wondering is if I should wire in a parallel set of terminals to the battery so I can clip my charger to it, while it's in the plane without disturbing the connection to the plane electronics.

As a side-note, I am considering building my next glider with no motor. I am amazed at how lightweight the wings and fuselage of this plane are, as well as the micro receiver and mini servo's. The motor and battery pack are like bricks compared to the rest. If I do that, I'd like to consider using plain alkaline cells. Anyone doing this?

Regards,

Monkeyboy

Reply to
MonkeyBoy
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You will want to remove the pack from the plane to re-charge. Aside from being more convenient (you will be wanting a second pack VERY soon, trust me), if something were to go wrong during charging you are better off to have the pack out of the plane than to be trying desperately to GET the pack out of the plane in a hurry. Any time you fly an electric plane you will want more than one pack so you can be flying while one is charging. If the white plug you mention has a round peg and a square peg and a clip, that is a tamiya or molex plug and I would get rid of that ASAP. You are better off switching to Deans Ultra Plugs (my preference) or similar. There are many brands but those tamiya/molex plugs are crap. Put the male on the controller and charger and female on the battery. I would not go for alkaline batteries period. Many more options if you keep with the nicads and rechargeables are the only way to go both for convenience and cost. Alkalines would be good for one flight then toss em. This would add up something fierce!

Reply to
Fubar

I prefer Sermos; they seem to hold up very well, are easy to connect and disconnect, and keep both the battery and charger contacts covered. Also, since the + and - contacts can be soldered or crimped separately and installed in their separate housings which are then locked together, you will miss the joys of soldering the battery leads to the contacts and shorting the battery while doing it. They are a little larger than the Deans, and the Deans Ultra will carry more current.

Other than that, I heartily agree with Mr. Fubar ;-)

-- Mike Norton

Reply to
Mike Norton

yes. mandatory.

Convenient, yes, cheap, yes, able to take abuse without malfunction - no.

They are called 'Tamiya' connectors and are basiaclly ex car racing. There are many better and more expensive alternatives.

No. You MUST disconnect it. The pack will slowly flatten if left conected to the speed controller. ven if it is 'switched off' as this only disconnects the receiver, not the drive circuitry for the motor.

Its good practice to take the pack out for recharging as well. Get in the habit - its mandatory safety wise for LIPOS asd gets you in the habit of using one pack for more than one plane - also mandatory for LIPOS unless you have unlimited access to cash.

Can do, but a small NiMh pack is usally enough for receivers.

Just wait until you doscover brushless motors and lithium polymer cells, and you will be furher amazed at teh low weight, and high power.

You will not be amazed at teh cost tho. Not in te same way :-)

Reply to
The Natural Philosopher

The Deans Ultra will carry more than the 15A inserts of the Anderson Power Pole connectors. However, there are higher current inserts that fit the small housing that go to 45A - well more than Deans.

Here's the website for the "sermos" connectors.....

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I prefer Sermos; they seem to hold up very well, are easy to connect and

Reply to
David AMA40795 / KC5UH

Thanks, everyone, for the helpful information!

-MB

Reply to
MonkeyBoy

but they're so danged BIG!

Reply to
jeboba

If the standard charger puts out the standard 50-60 mA the very helpful people at Indwoods are either 1) blowing in your ear or 2) clueless as to basic charge requirements for Ni-MH - As a very minimum (for 30 hours charge time) you should have a charger that puts out 100 mA.

Red S. Red's R/C Battery Clinic

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us out for "revolting" information.

----- Orig>

Reply to
Red Scholefield

Funeral Services will be held at the following Ridout's Valley Chapel, Homewood Al 35209, 205 879 3401 services will be held at 2 pm on Monday. Jim McNeill has requested that in lieu of flowers donations should be sent to AMA designated for the McNeill Cup.

Reply to
sfrank

Oh dear, looks like I have problems Red. The charger I have on order is the 1000/1700 Mah dual jobby from JR.

If this won't cut it, is there a charger you would recommend? Regards, Jeff.

Reply to
Jeff Hartley

| On Sat, 22 May 2004 17:21:59 -0400, "Red Scholefield" | wrote: | | >If the standard charger puts out the standard 50-60 mA the very helpful | >people at Indwoods are either 1) blowing in your ear or 2) clueless as to | >basic charge requirements for Ni-MH - As a very minimum (for 30 hours charge | >time) you should have a charger that puts out 100 mA.

Oh, the 60 mA (?) wal-wart you've got will work with the NiMH batteries fine, but a full charge will take something like 50 hours. You probably won't be charging from nothing very often, so the full 50 hours won't be needed, but you do need to be careful, and keep an eye on that battery gauage if you don't charge for the full 50 hours. (This is a transmitter pack that we're talking about, right?)

Yes, a faster charger would be better, especially a peak charger that can charge it un a few hours, but what you've got will work. It will just require a bit more care.

| Oh dear, looks like I have problems Red. The charger I have on order | is the 1000/1700 Mah dual jobby from JR. | | If this won't cut it, is there a charger you would recommend?

If this charger will charge at 1000 or 1700 mA (not mAh -- mAh is a measure of current capacity, not current) then it'll be just fine. Though I'm not really sure what you've ordered ... do you have a model number on it?

Really, if you're at all serious about R/C, even if you only do gliders or glow and not electrics, you should have a peak charger. The temptation to go ahead and fly, even though you forgot to charge your batteries last night and so it's only been charging for four hours, is too high. And if you do (wisely) resist the temptation, well, you're not flying today, because you forgot to plan correctly yesterday.

With the proper plug, this charger --

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ought to be able to do receiver and transmitter packs. For only $30.

(Though I think you'd be better off paying $50 for this --

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because it can do two batteries at once.)

With a peak charger, you don't need to worry about planning far ahead. Looks like a nice day to fly today? Put your batteries on the charger now and in 0.5-2 hours (depending on charge rate), you're ready to go.

But even without one, the charger you have will work with your new NiMH pack. Just don't skimp on the charging time, and don't forget to watch the battery gauge occasionally, as you should do anyways.

Reply to
Doug McLaren

Bad advice is worse than no advice at all.

To assure a full charge the manufacturers recommend a minimum charge rate of C/20 or for a 2100 mAh pack this would be 105 mA (100 is close enough). The minimum sustaining charge, the charge required to maintain a pack at full capacity after it has been charged is C/50. Anything less than these numbers could be very marginal.

As for charging at 1000 mA, this will cook your pack in a hurry by raising temperatures to 150 C / 300 F (also enough to also ruin your transmitter when the pack goes into melt down).

-- Red S. Red's R/C Battery Clinic

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us out for "revolting" information.

Reply to
Red Scholefield

| Bad advice is worse than no advice at all.

Of course, you conveniently forgot to quote the best advice in that post. It's an old trick, but tried and true.

| To assure a full charge the manufacturers recommend a minimum charge | rate of C/20 or for a 2100 mAh pack this would be 105 mA (100 is | close enough). The minimum sustaining charge, the charge required | to maintain a pack at full capacity after it has been charged is | C/50. Anything less than these numbers could be very marginal.

Well, 60 mA on a 2100 mAh pack is C/35. So it's not lower than C/50.

Either way though, it's going to take a LONG time to charge. Long enough to not be practical (even though it would work in theory), which is why I pushed a peak charger.

60 mA will charge the battery pack, at least most of the way. It will just take a very long time, probably too long.

| As for charging at 1000 mA, this will cook your pack in a hurry by raising | temperatures to 150 C / 300 F (also enough to also ruin your transmitter | when the pack goes into melt down).

Well, I'm hoping it was a peak charger, though I could have been more explicit there. If it's not a peak charger, then yes, this would be very bad. Which is why I asked for a model number.

If it's a peak charger that charges at 1 or 1.7 amps, and can do NiMH, it will be fine. (For NiMH, 1A would be better than 1.7A -- the batteries would last longer.) But I'm not aware of any brand of charger of any sort that only has those two options, which makes me wonder what he's getting, or if he's even described it right.

Reply to
Doug McLaren

IIRC, the original post mentioned a 1000/1700 mAh JR brand charger.

The only thing I found in that range from JR, on the Horizon site, is a wall wart.

Not too many peak detection smarts in one of those.

As you said, a model number would have helped.

Reply to
Fred McClellan

Sorry, I don't know the model number. Apparently JR do a "standard"

50ma charger and a 120ma charger for use with batteries of 1100mah or more. It is the 120ma charger I have on order.

I can only go on the word of the shop that it is the correct charger, if it isn't it will go back....

Regards, Jeff.

Reply to
Jeff Hartley

that's the one Fred.

I can't find one one despite intensive searching. Believe me, I want the correct tool for this job and if you can suggest the correct charger I'll order it.

I've been out of the hobby for 20 years or more, the last radio sets I came into contact with were all dry cell and nicads were only just becoming widely available (affordable). It used to be that the radio side was the simple bit and the techie bit was the building. It seems to be the opposite way around now or am I just getting old ;-) Regards, Jeff.

Reply to
Jeff Hartley

| >IIRC, the original post mentioned a 1000/1700 mAh JR brand charger. | >

| >The only thing I found in that range from JR, on the Horizon site, is | >a wall wart. | | that's the one Fred.

Then don't use it! Send it back :)

As Red suggested, it'll fry your batteries quickly. You could use it, but monitor your batteries for temperature and take them off once they start getting warm, but you'd only have to forget once and it would cook your batteries. I have to wonder why they even sell this -- I'm guessing it's not being sold as a charger.

| I can't find one one despite intensive searching. Believe me, I want | the correct tool for this job and if you can suggest the correct | charger I'll order it.

Get something like this --

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$50, but it'll charge both batteries at once and at a reasonable rate.

Don't forget to pick up some charge leads as well.

There are better chargers, but this one will do what you need now. It doesn't cycle, and won't charge over 8 cells, so if you ever do get into electrics you'll want something better. But for glow planes and gliders, this will do very well.

If you want one that can do everything, get this --

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but it's $130. But I love mine ...

| It used to be that the radio side was the simple bit and the techie | bit was the building. It seems to be the opposite way around now or | am I just getting old ;-)

I think that the radio side is still the simple side. But maybe I'm just not acting my age :)

Reply to
Doug McLaren

In article ,

| >Well, I'm hoping it was a peak charger, though I could have been more | >explicit there. If it's not a peak charger, then yes, this would be | >very bad. Which is why I asked for a model number. | | Sorry, I don't know the model number. Apparently JR do a "standard" | 50ma charger and a 120ma charger for use with batteries of 1100mah or | more. It is the 120ma charger I have on order. | | I can only go on the word of the shop that it is the correct charger, | if it isn't it will go back....

Oh, if it's only 120 mA then that would be fine. I was thinking it was 1000 mA or 1700 mA, which is way too much.

Is it 120 mA in both the transmitter and receiver circuit? If it's only for the receiver circuit, that won't help much.

In any event, you'd probably be better off getting one of the peak chargers I mentioned. This JR charger would charge your battery in 16 hours, where a peak charger could do it in two or even less.

Reply to
Doug McLaren

Indeed, the radio systems available these days were unimaginable twenty or more years ago.

The Great Planes/Electrifly Triton charger is an excellent offering.

Somewhere around $130 plus shipping, and well worth the money.

Handles NiCd, NiMh, Pb, and the lithium types.

Programmable every way from Sunday, with something like 8 pre-configured battery 'profiles' in memory. Fiddle those up to suit your needs.

An optional thermal probe is available for LiPoly and NiMh types, and it's a good idea if you use those battery chemistries.

Been a long time since I was impressed enough with a modeling product that I bought two of 'em, and that's what I did - just put my second Triton in service a couple of weeks ago.

The manual is available online at

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Read all about it.

Pretty snazzy rig for the money.

Reply to
Fred McClellan

You don't use a 9Z or you build scale models, then . . .

I'm struggling with how to hide the servos etc. in the wide-open great big cockpit of the 140" L-4, where everything, and I do mean _everything_ is in view. There's a limit to how many S5301s you can hide under one seat.

Compared to that, the 9Z is a piece of cake . . . 'cuz I keep the programming manual in the carrying case !

Reply to
Fred McClellan

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