DIY LiFePO4 Ham Radio Battery Backup System

Build A Quick And Easy LiFePO4 Ham Radio Battery Backup For Your Ham Shack!
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[@betterl8thannvr]

Try that same setup with a 100ah lifepo4 battery down down to near zero. Your power supply will be very unhappy when the battery pegs your power supply at the current limit. The epic pwrgate limits the charging current, and has configuration options for different charging options. For example, it's not great for your battery to constantly float it at 14.4v. It's not going to kill it overnight but will shorten it's lifespan. The pwrgate will charge it up using a proper cc/cv charging profile and then turn off the charger and let it float down to whatever voltage you set it at before topping off the battery. It will also protect you if a cell were to die in the battery. A "12v" lifepo4 is 4 cells. If one dies you will potentially be overcharging the other 3 (depending on the BMS) whereas the pwrgate will see the voltage is too low and give an error.

[@skipkazmarek6334]

Good advice on the diode. I'd definitely add a 30V/30A Schottky diode between the power supply and the battery/load connection to prevent the battery from back-feeding into the power supply (even though it will give an 0.5V drop in supply voltage), which means you'd have to adjust the supply voltage accordingly. I'd also make sure that the rated current of the power supply was adequate to supply BOTH the operating current of the radio (maybe up to 25A), plus the charging current to the battery (limited by the BMS to 0.3 to 1.0C?), plus a margin for safety.

[@kd8cap-joe35]

Great video Mike!!! Backup power is a Must. Years ago, my Kenwood TS2000 was on the nightstand next to me. We woke up to a contant clicking sound. Our power was flashing on and off. A friend of mine (another HAM) designed a circuit for me with a contactor switch and a very large capacitor. I put a Lead acid battery under my bedroom under the house and ran the positive and negative the floor. When the power would flash all you would hear is a click. The capacitor did not allow the radio to even flinch. I have the same circuit in my rack mount box. When I drove truck the rack mount box was strapped to the passenger seat. It was powered by the AC power supply in the box which was plugged into the power inverter in the truck. The Battery backup side of the box was plugged into the 12v CB power supply so if the inverter lost its mind the radio would still have power and I could safely power down the radio. Flash forward, I'm retired due to Covid19 complications which means I have more time for radio. My first Lifepo4 50ah battery is on its way. I'm building a battery box that will serve 4 purposes: 1)At home, power backup for the Rackmount box (Big Boy that houses my FT991A), 2)Backup power for my Oxygen Concentrator (incase my generator fails or I go camping), 3) Can't go camping without fishing so It will also power the trolling motor. and 4) Hopefully the box will house my Kenwood D700A and FT891 with the tuner and signalink. I may have to build another stand alone radio box. Before we go camping it will be a 100ah box. But due to limitation of funding Im starting with 50 and tieing another 50 in just before we go camping.

[@stevecolby6505]

It is a wise practice to have a DC to DC charge controller between a charging source (power supply or alternator in your car) and a LiFePO4 battery. LiFePO4 batteries will take as much current as you give them, unless the BMS cuts out at over current protection. The high current consumption can potentially exceed the output current limit of your power supply or alternator. This is how they can be damaged over time. The DC to DC charge controller limits charge current and keep everything happy and within its limits......

[@TimGray]

or just get a battery with a more advanced BMS so you can set charge current. Mine I connect via bluetooth to my phone to the battery and tell it "Charge at only 10 amps max".

[@quantumradio]

Good video Mike. My 12 AH LiFePO4, AC->DC wall adapter, and charge controller are all from Bioenno Power. I connected the components to make my main "power pack". The setup also allows for plugging in a generic 100W solar panel to charge the LiFePO4 battery when operating remotely. Took it out for WFD but didn't deploy the solar panel due to overcast skies. I used it for ˜7 hours w/the Xiegu G90 and it still had plenty of charge leftover. My latest project is a mini "power pack" that uses 3 18650 batteries in series. This one's very light & works for ˜ 4 hours w/the G90 before quitting. Keep up the good work Mike! 73.

[@kenluning909]

Nice video using the power poles. I use something similar for my battery go box. LIFEPO4 is the way to go. Lot's of good brands available out there these days along with portable solar.

[@AG7SM]

And just like that you have simplified a project I'm working on.

[@cbureriu]

I love simple stuff that just works

[@mikemiles3068]

Execelent Job of explaining this Mike I have been doing this forever and it just works 73 KV5P

[@Aimsport-video]

On most BMS cell balancing only happens when voltage is topped off, well above 13.8... so over time cells in this configuration could go out of balance. Great way to clear one's shack of power supplies without reverse bias diodes. So glad you pointed that out.

[@hamradiotube]

While I agree with you on the balancing over 13.8, keep in mind, my power supply is set at 14.5V, and I mention that LiFePO4 should really be charged to 14.6V. Balancing will occur with an intact BMS no problem in the configuration I show in this video. I wouldn't worry about balancing at all unless you were only charging to 13.8 or so. 13.8 is NOT the voltage to charge a LiFePO4 battery at all. Fortunately I made the message of diodes clear enough. That was what I was really worried about.

[@headleyryan]

Mike, your method for battery charging definitely works; but it is one that I would only recommend for actively monitored charging. You are correct that the BMS is perfectly capable of protecting and balancing the cells, but it is only one layer of protection. If you spend ~$900 on a 100Ah Bioenno, I would think you would want more protection--even if you are only risking destroying the BMS and not fire and exploding cells. In addition, keeping a LiFePO4 at 100% charge for days on end will shorten the overall life of the battery. For a backup system, you want it to be reliable for years at a time. I built my own 200Ah LiFePO4 battery bank, and I set the maximum charge voltage to 14.2. However, my system is charged with solar, not mains.

[@devonf6669]

There's another commercial product, BBM-1225 from Samlex that does a similar thing but with the current blocking diodes baked in. I haven't used it and it only seems to support AGM batteries unfortunately(voltage isn't right for full LiFePO4 charging). There's also one Paradan Radio DC Gate DCGATE40PLUS which is cheaper than the power gate that also could work with LiFePO4 from the looks of it.

[@robertmeyer4744]

That a simply way but will back feed power supply when off. blocking diode would be a good thing. also fuse everything and master switch on battery. the outher way to do this is have a seperate battery and charger. and just use a switch to select power. or even a relay with 120VAC coil . power goes out relay transfers to battery. just get a switch and/or relay to handle the needed power. this way you can keep 13.8V from power supply and you can shut it off when not needed. the separate charger keeps battery up. you just have to figure out your power needs and go from their. many ways to have backup power. the separate charger also allows you to add solar. 73's

[@TimGray]

Advantage of your cheaper design with a diode. if you have your battery topped up and a power supply. when you transmit the radio draws from both so if someone had a power supply that cant handle their radio at a full 100W out, the battery will make up for it. The purchased device is nice if you want a quick solution that is a buy and plug appliance instead of building. That diode will stop battery discharge through the power supply if it is off for extended period of time like a power outage. it's a good idea.

[@FatherMarty]

Diode protection is important. Burned up a RM-7A Astron trying this method. I have a PG40s power/battery but the output on the battery voltage is 13.8V even though the PS is 14.7V. Battery is a Bioenno 12V-12AH. BMS will protect the battery, but NOT the power supply. Would be nice to know how and what diodes to add, particularly if there could be a plug-in, inline system (like a fuse).

[@jterrellcreative]

Great video Mike! I might put something like this together. How would you add solar into the mix here, if you wanted to? Would you simply plug in the input from a charge controller that is hooked up to a panel or panels into the powerpole distribution block?

[@tjs2909]

Great content! Thank you! I’m curious, what would the best way to have solar in this setup?

[@hamradiotube]

The power gate would be a great way to add solar honestly. It does it all. Or get a solar charge controller and connect that to the battery.

[@DellFargus]

I use an old computer UPS with some LiFePo's in parallel for something similar. I haven't burnt down my garage yet.

[@kennethblackwell1137]

WEll done...!!😀😀😀

[@jethro9341]

Straight from Bioenno: "Please note that this battery should be charged using a LiFePO4 compatible charger, and not a charger for SLA batteries."

[@n3jw34]

Useful content, Mike, thank you!!!

[@hamradiotube]

My pleasure!

[@preventum]

I have my tekpower power supply set at 13.8 volts. Will it work ok to charge a LIFpo4 battery as you showed?

[@John_Henry83]

Is that power supply linear or switching ? And if it is switching does it have noise reduction control ?

[@JohnSmith-xi2oq]

Astron power supply all day long. Spend money on a good pwr supply. You are plugging at least 1k worth of radio in it

[@leedlbo9949]

Want to build my own battery for my van and only thing holding me up is using a dc to dc converter selecting the proper current

[@Veedy]

Did you just build a bomb ?!😮 Would be cool if that power pole distribution box had a 20a breaker built in 👍🏻

[@hamradiotube]

Yes. And I'm sending it to you lol! Oh wait, I wasn't supposed to tell you that.

[@MichaelSvenson]

Could you just do without the distribution block and, if the poles on the battery allow for it, go from the power supply to the battery, and from the battery to the radio?

[@dougdaniels]

Hmmm, I have a RigRunner in my solar battery box setup. I think I add this function pretty easily. Great presentation.

[@hamradiotube]

Thanks so much.

[@rbishopp]

Curious what happens when you key the radio? You might be taking a sudden draw on the battery as well as the power supply. Great point about the charging from the powergate providing 13.8ish volts to the battery for charging and not 14.6. Not sure if LiFePo life will be shorten from the lower charge voltage or not??

[@devonf6669]

Current should come from both the battery and the power supply. Split roughly 50/50. I'm curious too what the battery will do. If it doesn't reach 14.2-14.6v during charging, will the battery ever be fully charged? I did put my LiFEPo4 battery on a 13.8v charger for a few days and then moved it to a solar charge controller and it wasn't fully charged. For this use case, it might not matter to someone though.

[@hamradiotube]

The power gate says it charges lifepo4 to 14.5 volts. Charging to a lower voltage won't hurt the battery at all. In fact it will prolong the life. You won't be fully charged by any means if you are charging to only 13.8V. They do a lot of absorption at around 13.7-13.9. 14.4 would be a good place to stop charging and will be about 90+% charged and that will still prolong the life. Keying the radio would just pull power from both sources, and it would pull more from whatever source can deliver it easier. That whole path of least resistance thing.

[@Jiminico]

@@hamradiotube the Dakota branded chargers for their LiFePo4 batteries charge to a max of 14.4 volts. They do that to extend the life of their batteries and bc of their 11 year warranty. They don’t want to replace many batteries under warranty. Batteries can be charged with other chargers of course up to 14.6 volts and they also say that.

[@W9BTM-WQNX906]

Hey, Mike and Mike on the mic hi hi. I was wondering Mike, is that power supply special for lipo4 or is that just your average everyday ham radio power supply with good filtering in it to keep noise outta hf? If so I already have a home made Anderson gang and a Astron SS-50 power supply. Could I just pickup a lipo-4 battery and hook it right up or do I have to put something between my PS and lipo-4 battery to supply less amps to that battery?

[@hamradiotube]

It's just a regular old power supply. Other than I can change the voltage. It is RF quiet too though. You do need a supply capable of the voltage that LiFePO4 needs to fully charge (14.6V) A regular 13.8V supply will not be capable.

[@W9BTM-WQNX906]

@@hamradiotube this power supply is voltage adjustable I'm not sure how high it goes, I've got it tucked into the cabinet pretty good so I'll have to dig it out and turn it up and test it. So the amperage being it's a 50 amp power supply won't hurt the battery as long as voltage gets up to 14.6?

[@THESHADOW97139]

@@W9BTM-WQNX906 A year later... if I follow the idea correctly, I think you need a battery equal to or greater than the number of amps given by the power supply... correct?? 🤔

[@chucksw1]

I want to use a Lipo4 battery as a battery back for my secondary dc sump pump! Im tired of buying heavy lead acid batteries every 5 years and having to keep the water level filled on them! This gives me some good ideas! Anyone else try this?

[@will6051]

I will seond the shotky diode.

[@WX4CB]

perfectly safe and is the same way it works when you're doing an "easy" dual battery install in the car, that said, yes. you do need some reverse current protection and i would NOT recommend doing this with anything other than a battery with a build in BMS or PCS.

[@johnkaelberer237]

Hook a panel(s) ( Panels wired in series if you have more than one) to a charge controller and hook the charge controller to the battery. Lots of options on panels and charge controllers. Be sure to size the panel voltage/amperage output and the max input voltage and amperage of the charge controller in it. Do some research on charge controllers. Not all are RF quiet. The Genasun charge controller, though not cheap, are RF quiet as a church mouse. Best idea, build a battery box with a charge controller in it. Then it's just a matter of plugging in your panel(s) or battery charger to charge the battery in the box.....What's in the boxxxx ?????

[@fenderJ16]

First of all, I'm an idiot. So, keep that in mind. But wouldn't using the power supply to charge the battery run some risks as a power supply isn't directly intended to charge a battery? I understand LiFePO has a BMS but I am curious if in the event the BMS fails, could the power supply continously supply juice into the battery causing a failure or worse?

[@hamradiotube]

Hey me too!! There's nothing wrong with using a power supply to charge your battery, so long as you know and set the proper voltage for the chemistry you are charging. If you had a power supply that controls the current output as well as the voltage, that would be even better. Typically, even without a BMS you're still going to be ok. The main purpose of the BMS is to balance the cells voltage so they are all the same. Over and under voltage protection is just another feature they provide. Unless you are putting more voltage than the batteries were designed for (without a BMS), they aren't just going to keep taking power. Your power supply isn't necessarily pushing current into the battery, more, the batteries are pulling the power in from the power supply. But, if you were to have your power supply set to something higher than 14.6V ( LiFePO4 charging voltage), that would over charge them and that is generally a bad thing.

[@chrissewell1608]

Seems like you could add a solar panel, with a simple toggle switch. After the power goes out, then throw ON the solar power, at yhe flip of a switch. Its manual, but in the system. You still have to power the solar charge controller, with a battery, though? Hum...? 🤔 Anybody got an idea there? Maybe an added relay?

[@dougdukes1039]

Will this work with a Lead Acid battery?

[@thomasmiller2016]

My first "Power Supply" was two Duracell 12VDC 9AH UPS AGM batteries in parallel charged by a 4.5 Amp Automotive Trickle Charger. This powered a Kenwood TM-V71A for about 8 months. It was not Sad Ham approved, but worked flawlessly until I got a "Real" power supply. It still patiently occupies a corner of my workbench in the Garage waiting for the occasional kit build or antenna test. It even powered an IC-7100 once while I was testing a NVIS antenna in the front yard. KL4CF

[@hamradiotube]

Lol @ not sad ham approved!!

[@cchalfantusa]

@@thomasmiller2016 I’m still running off a single AGM 35AH kept charged by a battery tender. The hassle is carrying the relatively heavy battery from my patio, to my deck, to my truck depending on where I want to operate my FT-891. Driving me to buy a regular power supply or a 20AH Bioenno that I can charge with my existing Bioenno 2A charger for my little 6AH Bioenno in my 20W VHF/UHF field kit. Or add some power poles to my truck! Or all of the above ideally.

[@johnkaelberer237]

More excellent content. First of all, my wife see's nothing that goes into my shack. I keep her like a Mushroom....In the dark with Stuff shoveled over her. Makes life so much easier...lol. She's actually a pretty great gal, likes to see me happy. Buying and making Ham gear makes me happy. I love the money saving tips you are giving out. DIY is something Hams are known for. Before you buy, look for ways to make it yourself. Lots of satisfaction there. Rock on Mike. If I ever meet you, I owe you some shots.

[@TravelinHam]

I watched the whole video and still don’t know, what is your favorite childhood memory?

[@dwatson4]

I love spending thousands of dollars on radios

[@Bill-HRT]

Good demonstration, Mike. Thanks for the idea. 73 de K0WHW @Bill-HRT