Just wanted to share how I have rigged power on my Garmin Striker 4+:
Old school kayak sounders have run off the heavy 12V SLA batteries. At some point, the blue lipo battery packs were fairly common. Recently, the FPV-power batteries have become available - which look awesome, and are probably the low hassle way of doing things.
However, in my ebay musings a few weeks ago I came across a USB 5v to 12V converter which allows us to power our sounder from a standard usb power bank. Benefits of using the usb power bank are:
- It appears to work! The sounder/GPS works as expected. (however, some difficulty in keeping a depth read in less than 1.5m - which is probably attributed to the wet mount made for a lowrance that I couldn't be arsed adapting for the garmin)
- Plenty of cheap, high capacity USB powerbanks available that offer good capacity to weight ratios
- USB power banks are easily and quickly recharged, with many equipped with quickcharge technologies.
- USB power banks are also easily be recharged through solar or car chargers.
- USB power banks are really versatile! You will use them for purposes outside of kayak fishing.
Now the draw backs are:
- First, a 10050mAH USB power bank is 10,050 mAH at 3.7V = 37Wh. This means that excluding losses the capacity at 12V is about 3Ah - Still plenty of juice for a days fishing. Further, if you are looking at cost per Wh, it is only a little more expensive than SLA - it is possibly to get reasonable reputable brand (e.g. Anker, Xiaomi) 37Wh powerbanks for the $25-50 mark - and getting cheaper.
However, losses would be present: in the power bank the voltage is increased from 3.7V to 5V, and then in the adaptor, it is increased from 5V to 12V. I have not measured these losses, but given the adapter was purchased for $10 off ebay, they are probably significant. When purchasing your powerbank, it is worth googling the efficiency of it.
- Next, there is some noise introduced. Checking on the oscilloscope at work, there is a bit of noise in the output signal. However, this does not appear to affect the signal on the Garmin sounder/GPS unit that I am using. However, the garmin unit has seperate power and transducer cables, so your mileage may vary
- finally, you do need to waterproof your battery pack yourself. There are also water resistant usb powerbanks which may mean you can get away with the sistema clip container.
No affiliation with any brands, sellers or companies included in the post. You could probably find the bits cheaper/easier/sexier/quicker if you go looking, but Im happy with what I have!