Here is my first prototype for a tool battery based system for powering a ham radio and Raspberry Pi. There is a lot more work to do, but the concept seems to be sound!
That's an interesting idea if you've got a bunch of tool batteries on hand. Otherwise, 12v jumpstart packs are convenient, inexpensive, and have 15 - 20ah capacities...
Hi that looks good donot think can get any of them here in ZL mut look see, Thanks, 73 Pieter ZL1PDT / ZL1LIG
It all sounds good but, do you find it difficult to operate with the rig at an angle? I think it would give a person a stiff neck.
Those buck converters can be awfully RF noisy if you are unlucky. After trying various solutions to get the 16.4v of a 4S LIPO battery down to 13.8v, the cleanest option I found was to use an LM 338T voltage regulator of the correct current rating on a heatsink with a couple of resistors to set the required output voltage. i.e. the old fashioned method that has been used for years. The suggestion of using a car battery booster box has a similar problem - they tend to use a 3.7V LIPO and then up a Boost converter to take the voltage up to 12V - these converters can also be RF noisy. Good luck with whatever you end up with, but watch out for that RF noise! 73 Ed. As always YMMV.
Actually, I’ve been working on something similar. Except with surplus batteries from data centers. I’m not a QRP guy so a Honda generator and a few 40Ah 12V batteries paralleled in a 24V configuration with a buck converter is more suitable for the application. If you want a light weight and very reliable battery without the odd LiPo voltages look into LiFe (Lithium Iron) batteries. They have a very flat discharge voltage curve. I run a 60Ah LiFe in my electric kayak and it runs 12.5 to 12.6V until it’s basically discharged. The discharge voltage is so flat that you need an A/hr meter for a “fuel gauge.” I also have a 10A/Hr motorcycle battery LiFe that weighs roughly 40% of the lead acid equivalent. Maybe 12.5V is a little low but, if your running portable/QRP anyway it seems like a reasonable compromise.
After a few beers it looks level enough. I like this project. I might try something like this. He did say it was a work in progress so my nit picks are not likely relevant just yet. I'd add the correct resistor network on the USB port to comply with the USB-BC spec. A "dumb" USB device will just take whatever current it can get from the 5 volt pins. A "smart" device will try to talk to the charger and then resort to checking the voltages on the data pins to see how much current draw is safe. Some devices, with Apple devices being notoriously picky, will refuse to draw power if it sees a power supply that doesn't comply with the USB spec. My guess is that the Raspberry Pi isn't too picky. I'd also put in some kind of over current protection and some means to protect the battery from driving the voltage too low. A switch or two and some kind of indicators (lights, meters, or something) would be nice.
Some do. Most jump start batteries, however, are most assuredly not lithium batteries, OM. They are still 12 volt lead acid batteries in 15 - 20ah capacities. Included wall wart charger...usually a utility light...sometimes even a built-in broadcast band radio. And cheap. Get on down to Harbor Freight if you don't believe me.
I have something like what you describe, I'm not sure if I'd call it "cheap". Years ago I was talking with my brother about getting one of these jump start boxes with a built-in tire inflater (calling it an "air compressor" isn't entirely accurate as it has no tank). He likes to look for deals and suggested something similar but one with a radio and a few other gizmos in it. I got one and so did he. I got the larger PowerDome EX to keep in my Ford Explorer and he got the smaller PowerDome NX (because that had a radio with stereo speakers!) for his GMC 1500. After a while I thought this was a decent enough purchase. I couldn't exactly expect a jump start from it but I could hook it up for a few minutes to warm up the battery in my Ford to the point I could get it to start after an especially cold day in a parking lot. My brother melted his PowerDome trying to turn over a V8. He gave me what was left of it and I salvaged a few parts from it. Mine I had to replace the battery in it after a while, it's a SLA 18 Vh. The inverter in it is nice to run a fan on hot summer nights when the power is out. The radio is useful for some background music if you aren't picky on the station, as the tuner isn't all that great. The tire inflater is powerful enough but very loud. My Apple iDevices didn't like the built in USB charger port, and the lights on the PowerDome were too dim to be of much use. The cigar lighter style power outlet is useful though as it allows me to plug in all kinds of automotive accessories, such as an Apple compatible USB charger. These things are nice enough but I just wish they were built to more easily replace the battery. Considering the quality of the plastic case that holds it all together this is likely intended to be a somewhat disposable device, intended to be disposed of as a whole when the battery no longer holds a charge in 5 to 10 years. If I were to do it again I'd buy or build something like the PowerWerx PowerBox. https://powerwerx.com/megabox-portable-power-box-bioenno-batteries PowerWerx advertises them as a case for their LiFePO4 batteries but I'd put a SLA in it. To finish out the setup I'd keep a tire inflater and whatever other gizmos I thought I might need handy, perhaps even keep them stored inside the battery compartment since it opens up easy enough. Not exactly the same idea as using a tool battery for powering an Amateur radio but it's in the same ballpark. It's a battery to keep on hand for multiple uses, one of which is powering a portable Amateur radio station. One idea I had was to find a way to run some old 12 volt and 14.4 volt power tools off of 12 volt SLA batteries. Something that could adapt the battery port on a DeWalt power tool to a PowerPole. I would not intend for the battery to hang off the tool but instead be attached by a short power cord. I don't know how much current these tools draw from the battery so perhaps it's not practical.
I've used units similar to the one linked below for years. And have even jumped my truck off with them--and other people's cars too. Naturally, if the car's battery is really dead, one won't start it, but jumping it with another car usually won't work if it is that far gone, either. I would consider the ones like this example "cheap" since I've routinely gotten 10 years service or more from them. You can replace the batteries in most of them with fair ease. It's not a 2 minute job, but not much more than that, and you can get the replacement batteries at the usual places--like battery source. The only secret to keeping these batteries alive? Simple: charge for 12 hours after every use. If you don't use the battery over the course of a month, charge it for 12 hours anyway. https://www.harborfreight.com/3-in-1-power-pack-with-jump-starter-62306.html
