Battery set up

RK Flyer wrote:...........d cell batterys for starting my engines but they dont last long.

Where can I find a rechargeable battery & charger?

Thanks RKFLYER

Hmmmm. I use a pair of D cells in parallel and they'll last for a long time. Unless you're cranking for a long time or flying a lot, you might check your wiring and connections for a broken wire or loose joints.

I have crawled the same learning curve before I learnt that rechargeable batteries that has a nominal voltage of 1,2 Volts instead of 1,5 Volts that COX heads run on are just another costly but ill-hfated attempts to the glow-plug energizing problem.

I finally ordered a Hobbico panel http://www.ebay.com/itm/NEW-Hobbico-Deluxe-Power-Panel-II-NIB-/330487440685?ssPageName=ADME:L:OC:US:3160 that I mounted on the front of my toolbox, and power it through the cigar-lighter of my car when I am in the field. The panel is worth its price and is the ultimate solution as it also feeds my electric starter.

cheers: Duke, Thanks for the offer but it will be ahwile before we can meet up to fly again!

Meanwhile I'll order the Hobbico Power Panel if because of no other reason they look cool on the Field Box that I'll build someday!

Balogh, If I have this right the power panel works on a 12 v battery and allowes you to use 1.2 /1.5 to start your engine> Correct?

RK Flyer  

In the old days, the cox starting batteries were 4 carbon-zinc cells in parallel. They worked OK if you knew how to start an engine without leaving them connected for a half hour at a crack, and if they had not been sitting on the store shelf for two years prior to purchase. (that was an even bigger problem with the No.6 cells, as the only market was modelers and kids doing science projects) 2 alkaline cells are enough, but 4 will last more than double the time, as batteries are more efficient when the load on each cell is reduced.

When running 2 or more cells in parallel, it pays to disconnect them between flying sessions. No two cells will be exactly identical, and the highest voltage one will try to charge the lower voltage ones...and primary batteries don't really accept charge well, so the result is just that the higher voltage one ends up being depleted faster.

Mixing old and new cells, or different brands or carbon-zinc and alkaline is really bad. You can actually damage the cells that way. Due to lower internal resistance this becomes more critical when you use "better" batteries. Carbon-zinc is more tolerant of mismatch than alkaline and I have had a battery pack catch fire the first time I tried to parallel some NiMHs.

If you are using new cells from the same lot (same blister pack) then they are very close to matched, and a few hours at the field once a week does little harm...it is the sitting for a week or two between outings that hurts.

So using a holder ("battery box") that you can pop the batteries loose from when cleaning up for the day is a good idea.

This idea I got from Burt Goldsmith. I saw him popping his batteries loose at the end of the day and had to think about why for a while. Like most of what Burt does, there is a good reason.

RK flier yes the Hobbico runs on a 12v car battery and allows you to provide variable czrrent level to the glow plug by turning the knob on it. The COX heads glow with the knob close to its max setting.

Hi Richard, I've always used a Tower (Hobbico) power panel. You need a 12 Volt DC source to power it. There are more than a few ways to do this.

I threw something together recently that uses (x2) 6V alkaline "lantern" batteries wired in series; using a (x1) "short" jumper-wire with alligator clips on ea. end, to connect between the "2" battery's +/- terminals... (series) producing 12V. Connect the panels' red/positive (+) lead to ONE  battery's pos. (+) post, and the panels black/neg. (-) lead to the OTHER battery's neg. (-) post. This "series" wiring is a "chain", which doubles the voltage. I disconnect the batteries when not in use.

I've also used an automobile type 12V DC "battery charger" to power the panel, if there was a 110V AC source nearby.

One of those portable "car jump-starters" would also work.

There are also 12V. deep-cycle lead-acid batteries... even the small ones are bulky/heavy... but they're a great thing to have on-hand, along with an "inverter" for portable 110V AC power, during "brief" power outages. Deep-cycle batteries are designed to be drained and then "re-charged later"...  as opposed to an automotive battery's being charged "constantly". A typical use for a deep-cycle battery is for an electric fishing/trolling motor. The motor is a load "only"... without charging taking place. Once the battery's capacity is low; it is then necessary to recharge to full capacity.  

It's "always" a good idea to dis-connect a battery (or batteries) from a circuit when not in use, when it is convenient. This isolates the battery from the circuit that it's connected to. If there is the slightest of load/short-circuit (or even resistance between cells)... the battery will dis-charge quicker and battery terminals/connections may become corroded. There is a switch/terminal made for large lead-acid "top-post" batteries, called a "swan" switch, which disconnects the battery from the circuit if desired, by simply turning a knob. It can be used as a vehicle theft-deterrent or in a case where there is a "constant" significant load on the battery (enough to totally dis-charge it)... before re-charging can take place.

My experience is with Cox engines... and genuine Cox glow-plug clips... I solder-splice 4-6 feet of 18GA lamp-wire to my Cox glow-plug clip, and solder banana plugs on the wires' panel end, for use at the field. The panel's meter is helpful in diagnosing open circuits/weak plugs. I turn the glow driver down/off... before connecting to the engine. I give the engine a fuel-prime, connect the clip to the head and gradually apply current until the meter is in the "green" scale. This verifies continuity, and my engines will usually "pop/start" in this range. Once running, I back-off the glow-driver amps, while listening for changes in ignition... if unchanged, remove the glow-plug clip and tune for optimal. It only takes a few seconds once you've done it a few times... and it "can" help in identifying plug trouble.

Keep an emery board in your flight-tote, to clean battery/electrical connections. They get dirty real quick and should be cleaned/checked before a flying session.

A warm Cox engine will start on a "single" fresh penlight battery... It's the available amperes and a good connection that get the plug lit enough to start it. I personally wouldn't want to fly "glow ignition" without using a power-panel.