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However I don’t have a master solenoid or starter solenoid because my Clipper didn’t have one from the factory and I saw no need to have more devices to fail. They do fail, I can attest to it. So I crank the engine with Master switch off to prevent any electrical transient damage to sensitive electrical components.
If you have these solenoids I recommend you crank with alternator off and make sure you have diodes across the coil terminals to prevent voltage spikes when coil field collapse. This collapsing field can induce a transient spike into your main buss.
An extra safety measure is to have an Avionics switch and turn it off when cranking.
The rapid drop you see when you remove the charger and turn on master switch is the “surface charge” bleeding off.
That is normal.
Before testing a battery that has been recently charged the surface charge should be removed prior to testing. Putting a load on it until the voltage stabilizes will prevent a false test.
I am on my third J16 battery. 8 years on each and they will still start my emergency generator. I have never used a trickle charger and never saw the need. I have been out of the country and away from the hangar for several months, come back, flip the master on and I see 12.1 to 12.2 volts. The engine cranks normally.
If your Hawker J16 is running down when the airplane is unattended you have residual load drawing current.
The above is NOT applicable to your standard Gill Lead acid battery. The can self discharge. Never had that happen to my J16.
My Hawker J16 shows between 12.2V and 12.6V when I check it after a few days sitting, if it hasn't been on the charger/maintainer. I thought that these batteries were supposed to indicate above 13V when fully charged. If 13.6 or so is just a "surface charge" value, without any real capacity behind it, and that is considered normal for it to drop quickly (~5 minutes under full avionics load with the engine off) to around 12.1V, then I think my battery is fine. I don't have something drawing down the voltage when it's sitting. I have no loads when master is off. My TP is a 1956 and has one solenoid in the little black box under the seat. It is a starter solenoid. I still have my original master switch with two glass fuses. I don't have an avionics master. I turn on my radio, ADS-B-out transponder, ADS-B-in receiver, and intercom switches individually after the engine is running. Thanks Gilbert.
If your alternator field switch is in the ON position your voltage will be down to 12 volts within a few seconds, but if your field switch is OFF than the battery should remain at roughly 12.7 maybe 12.8 volts and not move until you start pulling it down turning things on. Those Denso alternators that BC modifies pull about 4 amps with the field ON with the engine not running.
I have the two 30amp fuse original setup like you, and my master switch is the on/off/on DPDT with the alternator field and battery power on both poles of the switch. Does the BC stc have you wire a separate field switch to turn the alternator on or is it like the original setup and turns on with the battery master switch?
You can get a nice digital dual volt/amp meter and see exactly what is happening to your battery. I have my volt/ammeter connected right to the battery with its own toggle switch so I can see the battery state without the master on and monitor it during the start, its always at 12.7 with nothing on.
You can pick these dual volt/amps guages up on ebay for less than a hundred bucks, people upgrading and dumping them when they upgrade to all glass, they might say 2 or 300 on the auction but cash talks, I send them an offer in a message for about a third of what they want and most times they dont turn it down.
If your alternator field switch is in the ON position your voltage will be down to 12 volts within a few seconds, but if your field switch is OFF than the battery should remain at roughly 12.7 maybe 12.8 volts and not move until you start pulling it down turning things on. Those Denso alternators that BC modifies pull about 4 amps with the field ON with the engine not running.
I have the two 30amp fuse original setup like you, and my master switch is the on/off/on DPDT with the alternator field and battery power on both poles of the switch. Does the BC stc have you wire a separate field switch to turn the alternator on or is it like the original setup and turns on with the battery master switch?
B&C STC requires a new separate field switch to turn on the alternator. I didn't realize they pull 4A current with the field switch on and engine off. Good tip on the dual volt/amp gauge. Thanks.
I have never used a trickle charger on an AGM, but I live in the cold where an AGM thrives. I fly and my alternator is always charging it at 14.2 volts and when I shut down and check the battery during postflight its at 12.7 12.8 and will be there when I come back. It never gets down below 12.7 unless I have something on drawing power from it, I would fluke it with everything off and see what is drawing power down if its not holding 12.7 for at least a month with no tric charger connected, feb in florda is not hot enough to bring it down to 12.2 volts after sitting a few days, if it were in the 20s it would take a year of sitting without use to bring a good AGM battery down less than 12.6 volts. Return it to odysey if its not holding 12.7 for at least a month without a trick charger.
Its the correct one for your plane, has an internal 50 amp shunt, send him a 50 offer and he might counter 100 reconter 75 thats how I do it and if they want rid of it you get it
Battery cells are 2.14 volts each. There is always a tad of loss at the meter. Years ago when everything I maintained had standard vented lead acid batteries it was common practice to check acid level and charge the battery. They always took a charge. Most everything I maintain today uses a sealed glass mat lead acid battery and they don't normally take a charge. To test condition on these batteries I use a load tester that is available from Harbor Freight. I have had a few Hawker SBS-J16 batteries go south prematurely but they are usually long lived. I had an amphib Carbon Cub in the hangar with a new battery. When I went to start it the battery was dead. Charged it, started it and the alternator was charging. A day later I went to start it and it was dead again. I have a DC current clamp my Dad got me for Christmas several years ago. With everything off I clamped it around the main battery cable, no current draw. This Carbon Cub has a USB plug that is fused from the main battery and hot all the time. Nothing was plugged into it but it had a .36-.39 amp draw. When I inspected the back of the USB plug under the panel I discovered an avionics shop in Maine had wired the ADS-B unit off the USB plug which was hot all the time. Problem solved.
I have seen those cigar lighter power sockets wired directly to the battery also, not a good idea if you leave a usb charger plugged into it, even with nothing connected to the usb charger it will pull a small current from the battery and drain it.
I have seen those cigar lighter power sockets wired directly to the battery also, not a good idea if you leave a usb charger plugged into it, even with nothing connected to the usb charger it will pull a small current from the battery and drain it.
Ok, I didn't know that. I have one. Digital voltage readout with two usb ports. Thanks!
Ok, I didn't know that. I have one. Digital voltage readout with two usb ports. Thanks!
I have one of these I used years ago, works fine, I like the 2" panel mount volt ammeter much better. Those chinese lighter socket usb voltmeters will create noise in your comms, your transmissions will be weak and garbled
Gilbert, are you using the Odyssey "dry cell" battery? What do you think?
I can tell you first hand that this will be the best battery you'll ever use. These batteries are TPPL (Thin Plate Pure Lead) batteries and will last twice as long as the other aviation lead acid batteries. These can be mounted any direction without acid spilling out.
The reason I know is that I work at NorthStar Battery (Enersys) where these are made.
After reading through all of the posts I think i understand that I can install the Hawker SBS J16 with a logbook entry, but need a svenns stc only if i want the breaker switch upgrade?
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Re: Odyssey Battery
Originally Posted by Gilbert Pierce
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