Hello All,

Just bought a Hobbico C-cell type glow starter. The problem is that the non-rechargeable C cell drains too quickly for my liking , and replacements are expensive.

I was wondering if I could use 2 x 1.2v AA 2500 mAh NiMHs in parallel (so that voltage remains the same & I effectively get twice the time on them)...or will these burn out a plug if kept on for a long time. Any other alternatives?

This is for my ST GS 40 and also later on for use as onboard glow for my gas-to-glow conversion.

Why not use a rechargeable C cell? They're readily available in both NiCd and NiMH versions.

Otherwise, from an electronics standpoint, two cells operating in parallel should work fine. The glow plug only cares about voltage, not the number of cell providing that voltage. Just be careful of drawing it down too far. Although not as risky as Li-Poly batteries, you can get cell reversal in NiCD and NiMH that will destroy the batteries. Just don't go below 1 volt.

Brad

Sure you can do,I am using a similiar battery for years.Works great.

Well I could use a rechargeable C cell but I havent been able to find them locally....and I already have a charger for AA size cells...

Can you please explain what cell reversal means?

Try Batteries +, they stock such batteries. And they are found in most metropolitan areas.


Cheers,

Chip

Sorry I missed one detail before...I stay in India. So most of the stuff you guys take for granted is not available here. We have to improvise unfortunately...

I, too, recently purchased a Hobbico C cell glo plug "lighter-upper", and so far, I love it. I've only used it in the field once, but it really produces a good hot glow. This is especially good for my Irvine 40, which seems to like a wet start, and the hot glow just makes it better. I get a first flip start now. I wasn't aware of this, but the nicad starters (Sure Start, etc.) put out 1.2 volts, where the C cell puts out 1.5. One might think that difference is not important, but it seems to be for my engines. I also like being able to just keep an extra battery in the flight box and not have to worry about discharged starters, etc. FWIW Glen

Glen, how many starts does it last you? I presume you are using a non-rechargeable Duracell or something like that?

I'm not sure how many starts it will last, as I have only used it for one flying session, and I think I made four starts with it. It has a Duracell in it, and I have a spare in my box. I hope to go flying today, so I'll report back, if I can remember . Glen

BKdavey, you have been missinformed on hurting a NiCad by running it below 1 volt. You can discharge a NiCad (as long as the current is limited to prevent excessive cell temperature rise during discharge) and it won't hurt it a bit; in fact this is a test you can make on a suspected bad cell to see if it has an internal short. If, when the external short is removed the voltage doesn't become slightly positive--usuall around 0.8 to 1 volt--you know the cell has an internal short. The only way you can reverse charge (and possibly harm the cell) is to force current through it in the wrong direction; i.e. reverse charge it; and the only way that can happen during discharge is to have two or more cells in series where one goes flat before the others do. The reason for the oft stated "don't discharge below 0.9 volts per cell" is to prevent just that happening--one cell going flat while the others are still forcing current though it.

Used the C cell starter at the field today. Four starts, no problems. The battery should have about 10 starts on it now, including some I did for bench runs. I'm very happy with the performance and the convenience of not having to remember to charge it. One potential problem with the unit is that it is a little longer than my nicad starter, and that might pose a problem for starting an inverted engine in a plane that sits low to the ground. I have a Nobler control line plane, and if I'm flying alone with a stooge, I'll have to put something like a piece of 1/4 under the wheels for starting. Shouldn't be a problem. Glen

I found the commercial c-cell batteries (non-rechargable) were only good for 10-15 starts at best. They wouldn't last the day for me. I went with rechargeables (Ni-Cd), and one battery lasts the whole day, but I keep a second handy just in case. They're part of my night before charging routine.

As for cell reversal, two batteries in parallel can exhibit this behavior. If one battery discharges faster than the other, it can develop an internal short and drain the other battery with a high current. Cell reversal can occur, but it is less common in NiCd. For Lead-Acid batteries (like many have in their field boxes) are much more prone to this.

Brad

I have found sub C cell Ni Cad igniters last all day for me. But I do carry at least two to the field with me. I also have a Horizon Hobby field charger that can charge the igniter, reciever and the trans mitter batteries using a 12 volt battery. One can use a motor cycle battery or an auto battery to charge up the nicads that way. While such chargers are a bit expensive they last for ever and are very convienent should one forget to charge something or discover a dead battery at the flying field. Since most people use an electric starter they usually have a 12 volt battery somewhere very close.

I know that you may be quite some distance from a source and may have to pay exhorbitant import taxes but I do recommend having a field charger with you at all times.

Cheers,

Chip

bkdavey, sorry to dissagree with you but YOU CAN NOT reverse charge a cell as long as there is no second cell in series or a source of current that can force current thru the cell in the wrong direction. No matter how many cells you put in parallel, none can force current the wrong way through any of the others.

I'm up to 18 starts with my c cell glo plug lighter. Still strong, still loving it. Glen

In response to your reccomendation of "field Chargers" for glow starters. Does anyone use the "Glow Plug" output of their power panel to charge their c size glow starter? It's not a timed output(so you must keep an eye on it,and stop the charge by removing it manualy);But for a quick boost just a minute or two will get you through the days flying.Then just charge as usual when you get home.It's save several flying days for me.

I do that with mine sometimes.

But I don't leave it on there very long.

Enjoy,

Jim

I have a Duratrax D-cell glow driver, with a 4,500 mAh Ni-Cd battery and charger.

It should be enough for 3 months... but it self-drains within 2-3 weeks, or so, so I still charge it before each outing.


It puts out enough current to light up all the glow-plugs of a Technopower 7 cylinder radial... but I don't have such an engine...

Thanks everyone for the inputs. I will most probably go in for AA NiCds or NiMHs since they will likely last very long when wired in parallel.

I'd be very leery of using the output of the power panel to charge your glow starter as that output is a series of 12 volt pulses typically 1 millisecond long followed by 9 to 11 millisecond period of no voltage. I doubt that you will damage the glow starter for short time use but you could lower the life expectancy of the power panel.

Whatever you do, don't be sticking a glow starter with a non rechargeable battery on the charge post on your field box. It may damage the glow starter case.

Enjoy,

Jim