I took a Fatshark battery pack that holds two 18650 li-ion cells and fed it into a buck converter adjusted to 6.86V output and used it to power my GP Extreme. I'm testing out a (TDI) Beach Hog coil at the beach. I have a Barrie Johnson Nuggettfinder MKII that has its own speaker/amp as well as speaker/phones volume controls. The buck converter has less than a volt dropout so it has a reasonable life of about an hour and a half. I did run into a problem though - if the coil got too near my scoop the detector overloaded. Something, the audio amp, the detector, I don't know which, overloaded and went into a low frequency oscillation. I thought I had fried the detector inputs but I shut everything down, waited a bit, and repowered and everything was fine. I can't duplicate the issue using an input signal from a signal generator into the Nuggettfinder - which has me scared now. It happened twice in the latter part of the battery life so maybe this is a factor? Is the GP Extreme designed to take overloads from large metal or is it at risk of frying? I bought mine with fried inputs and fixed it - don't want to do that again.
I may move to a buck boost converter, put a 2S battery management circuit on the pack, and use larger 26650 cells which would keep the voltage stable and last longer.
Got my BBB (Beachnut Big Battery) 11 hour (est) run time battery today. Hope to give it a spin tomorrow. This should help me from having to backpack extra gear around for 3 1/2 hours or until the first battery quits me. I opted for the standard headphone connector to keep things simpler. The standard FT hearphones seem to sufficient at this point. Although I have been reading a lot on some of the threads about adapting other headphone for the AQ. That may be something I need to address down the road but not for now. I am just now starting to discern one target from another and don't want to start the learning curve again. LOL
Thanks OBN for such a nice looking addition to my AQ. 11 hours is something FT really needs to think hard about now. Or at least the 8 hour version. That would be very do able I would think.
I will keep you posted on run times.
PS: I am not sure why my pics are sideways.
This Battery musical chairs .....was a big thorn in my side .....
This Pack is all black and well balanced it looks like the rest of the machine was built to compliment the battery pack ....I chose the M12 connector from my old 3030 headphones gray ghost when they made good stuff my daughter bought me a set for my simplex last Christmas never worked I called left a message never called back new In box .....still dead ....guess they went out of business...anyway ....
you can shift this a little up or down to balance it out a little more on coil control..
Good Job Big Joe...... please remember ole Jim hunts year round And on a good day 16 hours and Thirty Lashes....for insubordination Host the Jolly Roger ye sully sods...
In the queen’s English ....Gonna need pack number Two ?....
Happy Trails me Bucko’s
Just a heads up... Seeing a few of the charging leads coming apart at the head.
Could be a batch problem as some I have seen look 100% OK and have had some use...
Others seem to have started showing problems - see the 3 pics of my 2 charging heads AND the last pic.. (not mine) is at time of un packing; and was almost separated...
One of mine is not crash hot and the other could fail with a little push. A simple weld will fix the problem, but will be e-mailing ML service to let them know.
Just a short note on Joe’s “shorty” AQ battery. It fits well under the cuff and balance was not noticeably effected from the lighter than stock battery. Run time for me in “tone mode” was 6 hours 20 minutes. It is my understanding that in all metal it is approximately one hour less. The M12 (CTX) phones connector was a welcomed change and the power cable with a small loop and ninety degree connector also worked well. Get one of his battery set ups and avoid changing batteries in mid hunt, while they are available. I believe he has other set ups with even longer run times. Knocked it out of the park again Joe, thanks.