Steve's Impulse AQ Hip / Chest Mount Battery

[Steve Herschbach]

Click or double click any photos in this article for high resolution versions.

I bought this 4 x 26650 battery holder on eBay after quite a bit of Google work. They are a surprisingly rare item. It comes with sleeves that can use 4 x 18650 batteries also. It ran me $29.65 delivered including shipping and tax. I ordered it on June 25th and it arrived from China on July 14th. The holder delivers 16.8V via a DC adapter plug or 5V via a USB outlet. It has a thin oring on the lid for an IP67 seal.

I also ordered an IP67 M8 4 pole 16.4 foot female to pigtail cable from Automation Direct for $10.50 plus shipping and tax. I ordered several different cables so lets add $5.00 for s&h for this one cable. They delivered next day!

And finally 4ea EBL 26650 batteries from Walmart for $20.99 free shipping, delivered in a few days.

Total parts cost about $70. I have a 26650 charger already that came with my Tarsacci so you'd have to figure that. Some sets of the batteries come with a charger. By the way, the EBL seem in short supply lately.

I shortened the power cable to 5 feet, more than enough to set the detector on ground if need be. The DC adapter that comes with this battery box is great. Blue wire to negative post and brown wire to positive. Warning - I am not vouching for the polarity. I used a multimeter to check my AQ battery and matched that. You should do the same. I take no responsibility for anyone doing this mod and blowing their AQ! The black and white are headphone wires. I hooked up a 1/4" female jack to those.

I am using the AQ mostly as a wader unit employing some true chest high waders that have a big pocket on the inside front. I'll drop this battery in that pocket and plug my Sun Ray Pro Gold headphones in. I could use my TaoTronics to go wireless, but that seems pointless the way the battery is mounted near my head. I need to determine run time with four 26650 batteries - should be way better than the current 3 (all metal) to 3.5 (tones/mute) hours running time I get with the Fisher battery. Enough that I probably will not need to do a battery change at all and perhaps enough for a long day. I also need to determine how the detector handles without a battery under the elbow. Lighter of course, but too nose heavy? Should be fine in the water as the coil is neutral. Maybe too nose heavy for some people for dry beach use. We will see. This would be a great belt hip mount battery for dry beach use. I suppose it could also be mounted under the elbow, perhaps with the included strap, so I'll consider that also. It would balance well like that. It is IP67 rated and with proper headphone / power cables might be good enough to use under arm for wading / shallow dunking use at least.

Operating sequence. Power up battery pack (it has its own power switch) then power up detector. Power off detector, power off battery pack. Doing otherwise may trip the circuit protector on the battery pack, necessitating removing and reinstalling the lid to reset. The pack has its own built in battery level indicator. And it may be used to charge a phone or other USB device! I was warned this USB capability might create interference in the AQ, but that has not proved to be an issue so far. The two circuits, 16.8V and 5V, appear to be isolated.

Powered up - and no smoke!

I really like this. Very easy for a not super skilled person like me to do, less than third the cost of a spare AQ battery, and should get well over twice the run time. If I had another complete set of batteries ready, it would be an easy swap for even more running time. It leaves only one cable to the rear end of the detector, and that is my only concern at all - I will try and beef that up and protect it better. I'm thinking a rubber boot that clamps completely over the end of the detector rod. I ordered a couple like like the one pictured below to see if it will stretch enough to work. Long story short is there is a very good chance this will replace my Fisher batteries for most of my use. This is why I had no problem getting the Limited "wader version" of the AQ as I find chest waders to be a good option at Tahoe and it's cold water for all but a couple months of the season when the water gets reasonably warm for mask and snorkel work. I used to do a lot of ice diving with drysuits while gold dredging, but am not looking to get quite that serious any more. 

Joe’s Fully Waterproof 26650 Alternative

Description:

Features:
100% brand new and high quality.
Without 18650 battery. You need to prepare 4x 18650 or 26650 batteries yourself to use.
DC 5.5x2.1mm interface has input and output functions, with DC adapter, easy to use.
DC 5.5x2.1mm port for 16.8V devices
USB 5V Port for Charging Smart phone GPS Tablet PC or 5V LED Light and more.
Improve replacement battery pack fixes inconvenient shortcomings, greatly facilitates the users of the battery pack DIY requirements, without spot welding battery, thereby greatly reducing the battery internal resistance, improve the battery discharge performance, so as to effectively improve battery life
Power supply: you can use 18650 rechargeable lithium battery as a power source
The output side: USB and DC dual output power supply function,DC output voltage is 16.8V(can power the 16.8V device, such as the bike light), USB output voltage is 5V(can power the cellphone and other 5V device), to meet a wider usage scenarios, the product comes with overcharge and over discharge protection, protection of the battery is more safe and sustainable

Specification:
Material: Plastic+metal
Color: Black or Red
Input Voltage:DC 16.8V
Output Voltage: DC Port 16.8V
Standby current Under 80μA
USB Output Voltage: DC 5V
USB Output Current: 2000mA
Overcharge Protection Voltage: 16.8V
Over Dischage Protection Voltage: 10V
Over Current Protection Voltage: 7.2A 
Size: 9x6.5 x 6.5cm
Cable length: 29cm
18650 and 26650 Batteries are not Included

Note
Please put in battery in a right way.
Charge it when power indicator light flashes.
Don't use the device in the water. Waterproof standard is IP67

Packing list:
1x Waterproof 4x 18650 /26650 battery box case.(without battery )
1x 5.5x2.1mm adapter
4x 18650 to 26650 battery converter

 

[cudamark]

Looks like a great option! 👍

[Steve Herschbach]

The detector without battery weighs 3.2 lbs, a solid pound lighter that with the battery. And while it may not be as well balanced, I could swing it all day like that with no problem at all. But then I am used to much heavier detectors, like the ATX and GPZ 7000.

Here is a mockup of what this would look like with the 26650 battery pack simply strapped under the armrest using the included velcro strap, which would work just fine. It would need a different power cable setup. Imagine the square USB outlet at a headphone jack instead. The whole thing might be waterproofed but I think I'd submerge the battery box at the bottom of a swimming pool for 24 hours and see what happens before I'd go that far. Joe has the better alternative for that already.

Replacing the Fisher battery with this 4 x 26650 alternative under elbow puts the weight right back at stock, 4.2 pounds, but with a much longer run time (to be determined).

[okara gold]

I'm really impressed at how creative you can be. I need help changing the batteries in my Ray-O-Vac flashlight. 😄

[Joe Beechnut OBN]

 

Great Job Steve!! For the price and setup you can't go wrong. 

Powered up - and no smoke! Love that!

We have the same wiring colors. The good, the Brown is Hot, and the Blue is the Neg..Same as the Excalibur's wiring. So it's easy for me to remember. 

 

[cobill]

Steve,  good engineering job on that AQ hombrew battery system! I followed your design and just ordered the battery holder and cable, but now the EBL 26650 are out of stock on every website! Since I'm awaiting my AQ, I have some time to wait for the batteries and components.

Bill 

[Steve Herschbach]

Battery options are evolving so rapidly some stuff is becoming obsolete before it hardly gets started. According to this article that is the case with the 26650 battery. It sounds like many of them are unreliable "rewraps."

The battery holder does have sleeves for 18650 batteries. I have two of those left over from another project, and may have to get a couple more just to have a complete set for this pack as a backup.

[Joe Beechnut OBN]

3 hours ago, Steve Herschbach said:

Battery options are evolving so rapidly some stuff is becoming obsolete before it hardly gets started. According to this article that is the case with the 26650 battery. It and this other article recommend various 26650 alternatives, but sounds like it may be a bit risky, especially on eBay, which has pretty loose standards on this sort of stuff.

The battery holder does have sleeves for 18650 batteries. I have two of those left over from another project, and may have to get a couple more just to have a complete set for this pack as a backup.

I'm not sure about that web site, those UltraFire batteries are junk..and they have them as #2..??..I've learn best to buy the brand names...Like Samsung, Sony, Panasonic, LG...anything with fire in the name is a reject from the mentioned brand names, one's that did not pass spec's, and has been repackaged. I'm new to the EBL's but from what Carolina, Dew and looks like AAron says they are good..

https://www.18650batterystore.com/18650-Batteries-s/106.htm

 

[cobill]

Steve, 

Based on the website I ordered the 4-pack 26650 8000 mAH li-ions, flat top battery with protection and a 2 slot charger from Amazon.

https://www.amazon.com/dp/B086RGS6TX?tag=homeelectr0a1-20&linkCode=osi&th=1&psc=1&keywords=26650 Battery

Bill

[Steve Herschbach]

I agree Joe and I'm not vouching for any of them except the EBL ones I have. I deleted that second link. Supposedly none of the big name guys are making 26650 batteries anymore is the main problem.

Bill, I guess the main thing is these things are dirt cheap, so not like we can get burned too bad. Only need to come up with four good ones.

I ordered the rubber boots I linked to above from Amazon. They are not as thick walled as I hoped and do not add much strength, but at least a little protection is better than none. I'm giving this a go tomorrow and will report back.