What battery for EMCOMM go box

[19dsniper]

Just as described. Im trying to figure out what battery to use for an EMCOMM go box. It would most likely be used for remote ops while out away from most power. I say most because if i need to charge off a running vehicle i can, but don't plan on using a generator.

It will be used with a Yaesu FT8800R Vhf/Uhf. radio
Specs:
RX: 0.5 Ah squelched
TX: 8.4 Ah on high.
Tx power: 5/10/20/50 watts

I plan on using 5 watts whenever possible. But knowing that i may need to bump it up sometimes and that needs to be considered.

The way i learned it for run time was: 10x(battery capacity in Amp Hours) Divided by the load in watts.
The charts listed by BioEnno don't match up with the numbers i am getting.

The 2 batteries I'm considering are a simple 18 Ah SLA $37.00
Or a LiFePO4 20 Ah at almost $200
I would love to save the money and buy cheap, but knowing the LiFePO4 is good for 5-10 years and 2000 plus charges might be worth it.
Also, if im understanding this correctly the LiFePO4 can be run down to 10%-20% before needing to be recharged and still maintain a voltage of 13.4-13.8 volts. This would actually give me 32 hours run time (80% discharge) on the LiFePo4 battery, compared to the 20 i would get from the SLA (50%discharge).
Am I looking at this correctly?
For those of you who have used your EMCOMM go box, what do you consider acceptable AH for this type of setup. For the most part it will be used in a field setting without a possible means of recharging for a little while. I am looking into setting up some small solar to top it off or charging it off of the vehicle when i get back to it.

When helping out with Hurricanes Irma and Harvey last year, I felt the need for some type of field kit/EMCOMM kit other than my vehicle mounted radio and portables i brought with us. As soon as we pulled out, we left the guys in the back with nothing but 5 watt portables. It would be nice to be able to drop off a box and allow them to get an antenna up with a little height and some higher power in these situations.
Current plans are to have the battery and radio with cables and roll up slim Jim antenna in 1 box.
What are your thoughts on Amp Hours and battery for this type of situation?
Keep in mind it needs to be fairly portable and im not looking for a Group 34 deep cycle marine battery. Something that will keep all parts together in the same box or case is best.

Thanks for any help.

 

[jonwienke]

Lithium anything is better than lead anything. You pay more up front, but save in the long run because the battery lasts longer. If you don't charge to absolute max and don't discharge to absolute min, a LOT longer. Plus lithium is about 1/3 the weight and 1/2 the size. And it has a much lower self-discharge rate, an important consideration for something that sits in storage a lot.

 

[AK9R]

I have heard good things about Bioenno Power LiFePo4 batteries. They aren't cheap, but, reportedly, they are top quality.

https://www.bioennopower.com/

 

[jonwienke]

LiFePO4 Prismatic Battery: 12.8V 100Ah (1.28 KWh, 10C Rate) - UN38.3 Passed (3.2Vx4 DGR)

Probably overkill, but they make smaller ones.

 

[mmckenna]

I think these guys are right.
Consider the weight. Lugging around a lead/acid battery can get tiring. Not impossible, but if money isn't the issue, weight should be your next concern if portability is a requirement.

That saved weight can go into better antennas, solar charger to extend run time and/or more coax to allow getting the antenna up higher. Or, a cooler full of beer, which would probably be much more welcome if the crap hits the fan.

A 30ah or so SLA battery would be an option to consider if price is a concern. Comparing number of charge cycles gets a little questionable, how many times do you -really- think this will get deployed?

 

[jonwienke]

Comparing number of charge cycles gets a little questionable, how many times do you -really- think this will get deployed?

Perhaps, but given the percentage of time the kit will be in storage, self-discharge rate is a concern, and for that, lithium is a clear winner.

 

[sloop]

Don't forget some way of charging the battery....if you are using battery then that should mean no ac power to charge the same. A solar panel might be an option. Northern Tool has the complete 80 watt kit for $279.99.

 

[19dsniper]

LiFePO4 Prismatic Battery: 12.8V 100Ah (1.28 KWh, 10C Rate) - UN38.3 Passed (3.2Vx4 DGR)

Probably overkill, but they make smaller ones.

This is a neat battery and as much as i would love to have 100 Ah, this one is 33 lbs and a little much for the kit im looking at putting together. Especially the price. I did however look at this one: Custom LiFePO4 26650 Battery: 12.8V 19.8Ah (253Wh, 7A) w/ PCB & 6.0" 18AWG Open Wires But it is $99 more than the 20 Ah Bioenno.

That saved weight can go into better antennas, solar charger to extend run time and/or more coax to allow getting the antenna up higher. Or, a cooler full of beer, which would probably be much more welcome if the crap hits the fan.

A 30ah or so SLA battery would be an option to consider if price is a concern. Comparing number of charge cycles gets a little questionable, how many times do you -really- think this will get deployed?

Haha. Yeah, I hear you on that one. We definitely ran into both types. Those that wanted to help or need help themselves. And others that were just there as on-lookers just hanging out and not contributing. Honestly i couldnt tell you. No one really knows, but as i get into Amateur radio a lot more, i would like to have something small that i could use with a Yaesu Ft-857D. So this project will serve double duty for that as well when we head to national parks and other places. Part of the reason im trying to keep the weight down is so i will actually want to use it more.

Here at the house i actually don't use a power supply. I will get one eventually. I actually just use 12 Volt deep cycle marine batteries. It has worked out very well so far. I keep a Multi Stage charger on them so that they can float and stay topped off all the time. I check the water in them at least every month and also the specific gravity about every 3. Its been great for times that the power goes out or we have really bad storms. I never loose coms that way.

Don't forget some way of charging the battery....if you are using battery then that should mean no ac power to charge the same. A solar panel might be an option. Northern Tool has the complete 80 watt kit for $279.99.

I do plan on adding a solar setup specific to this kit after i figure out which battery to go with. I am currently running a 100 watt Renogy monocrystalline solar panel with a 4 stage PWM solar controller that will work with all types of batteries EXCEPT the lithium. So once i make up my mind on what battery, i just might have to swap out to a different controller.

Thank you everyone for all your feedback. I like getting different opinions as it encourages me to research other avenues that i may not have considered before.

Keep the feedback coming!

 

[wrath]

Solar panels have come along way ,almost all our builds with utility or chief officers vehicles have small solar panels mounted to the roof that will run warning lights and radios all day on scene with the vehicle turned off ,never actually needing the battery involved to any large extent. And with flexible roll up panel arrays you could mount the controler in the box and drape or suspend a panel nearby.at this point in technology your more limited in funding than function.

Sent from my SM-T810 using Tapatalk

 

[vagrant]

I enjoy VHF/UHF contesting several times a year. I run Single Op Portable which limits me to 10W output. I transmit quite a bit from Saturday morning until Sunday afternoon. I also talk a bit on Friday evening as well.

- I use a 100W flexible solar panel and a controller
- I use a 35AHr sealed battery from Harbor Freight
- I use a splitter that offers Anderson power pole connectors
- I also have a meter inline on the main radio that allows me to see voltage and amps I have pulled, currently pull as well as the current voltage.

I typically use a Yaesu 817ND with low power draw and I have used a Yaesu 897D, which draws a few more amps even at 5W power output. That 35AHr battery also powers 220 MHz and 900 MHz radios that are always on for RX and I do TX as well. It also powers a handheld I leave on to monitor VHF/UHF FM call frequencies.

I have used that same battery for several years. Sometimes it was cloudy and rained. When not in use I top up that battery monthly at home. The battery and solar controller fit into a plastic ammo can style box, but it probably weighs 25 pounds all together.

I previously used an 18AHr battery, but mostly cloudy days were not friendly overall for my power needs. I transmit a lot and the squelch is open.

Unless I am on foot, snowshoes or skis, I would not bother with lithium. The solar in particular does a lot of the heavy lifting until the sun goes down.

 

[dorslv]

Portable ops

The radio: yaesu 857d, antennas: Dr Ed fongs dbj-2 vhf/uhf, hf undecided( probably end fed wire type ). Power: 12V, 15Ah LFP Battery (PVC, BLF-1215A). Any comments/improvements are welcome. Thx DorSlv

 

[Murphy625]

Might want to consider purchasing a couple of Nissan Leaf battery cells off of ebay.. You'd only need two of them as they are 2s+2p for each pack. We "off grid solar" folks use them in place of lead acid because they last longer and are cheaper. A single Nissan Leaf or Chevy Volt battery (the whole pack) can power my entire home for two days all on its own.

Put 2 of them together and charge to radio specs (13.8 x 1.15) = 15.87 volts or around 3.9 volts per cell.. You can then allow them to discharge from 15.6v to 11 volts and probably harvest about 80% of what the pack is worth at full charge.

They weigh 8 pounds each (16 lbs total weight) and pack about 55ah of energy and they can deliver a lot of current on demand.

One of the problems with the consumer grade battery packs these little websites make is that the cell packs lack high-discharge currents. Look up the specs on them and you'll see discharge rates at 5 or 10 or 12 amps.. and you don't want to push your pack to its max rating on either discharging or charging.

Inside lithium batteries, the cathode and anode grow these microscopic structures called Dendrites.. They look like stalagmites or stalactites in caves, and when they grow large enough to make a connection between the anode and cathode, the batteries have a tendency to let their smoke out and they die and sometimes take anything combustible in the area with them.

They've been trying to solve the dendrite problem for almost a decade now. It seems that any membrane that blocks dendrite growth also wants to block electron exchange or break down on its own.

If you go lithium-anything, you must use a BMS (Battery Management System). This is a tiny box that monitors the cell voltages and bleeds off any energy if a cell starts to over-charge. You'll also need a battery charger with an adjustable voltage set point.
Some of the better lithium ion batteries like the "Battle Born" brand, are called "Drop in replacements" for lead acid and will have the BMS system build into the battery.. Make sure you're sitting down when you see the prices.

Do not attempt to charge a lithium battery that is frozen.. If you operate in cold climates, you can discharge them, but never charge when frozen cold.

 

[sloop]

check out Quicksilver Radio at qsradio.com. The have batteries, voltage readouts, complete ecomm boxes with battery, readouts, connectors and even a vhf/uhf radio. If nothing else you can get some great ideas on parts and placement.

 

[iMONITOR]

Don't forget some way of charging the battery....if you are using battery then that should mean no ac power to charge the same. A solar panel might be an option. Northern Tool has the complete 80 watt kit for $279.99.

Harbor Freight has a 100 watt kit for $199.99
https://www.harborfreight.com/household/renewable-energy/100-watt-solar-panel-kit-63585.html

 

[Murphy625]

If you go solar, you really want to stay away from anything Harbor Freight sells.. In fact, if it has wires then I wouldn't buy it at harbor freight at all.. especially if its a life or death situation.

Solar battery chargers come in two flavors, PWM and MPPT. PWM is "Pulse Width Modulation" and its horribly inefficient and wastes up to 70% of the power a panel generates. But PWM chargers are cheap..

MPPT chargers will maximize panel output at around 85% to 98% efficiency but they cost three times as much..

You need to look at what's available for power to charge the batteries. A running vehicle can charge almost anything.. a small generator is great if fuel is available.. solar is even better but a lot more expensive than finding a running car or lawn mower that has a battery.. Heck, you could even charge from a motorcycle that uses electric start if its available.

 

[nanZor]

For EMCOMM use, my choice would be lithium. Why?

Most SLA batteries are murdered by their owners over time, with either overcharge or neglect. Many crappy battery chargers are available to help in this degradation process.

Lithium: Which one? LIFEPO4, (3.2v nominal) or the OTHER lithium batteries which are 3.7v nominal?

DONT EVEN THINK of using the 3.7v nominal batteries from Tesla's, Leafs, etc. Those are crash-victim batteries for one thing. And unless one is doing that already with the requisite skill and safety to do it properly - well, lets just say they aren't reading RadioReference.

Choose LFP, or lifepo4 which is far easier to maintain, (not to mention the ease of slapping 4 of them together to get to 13.8v nominal. OTHER lithium chemistries that are 3.7v nominal require more voltage regulation to accommodate. Slap 4 of the 3.7v varieties together and you have 14.8v nominal, which may be too much for your gear without additional regulation.

Non-lifepo4 - 3.7v nominal - varieties of lithium chemistries are smaller than lifepo4, but are much harder to maintain safely due to their energy density. Basically LFP 3.2v nominal cell packs are about 2/3 larger than non-lfp, but the iron-phosphate (the "FeP04" part) molecules are greedy little suckers who don't like to release oxygen and keep it all to themselves. Thus, unless you set your *infrastructure* on fire due to current overload, the cells themselves are generally the safer bet. Not as convenient due to their larger size, but generally one can accomodate them, unless you want 500ah in the palm of your hand.

Tip: when using LFP, or lifepo4 for EMCOMM use, do NOT store them at full charge forever! This means that when you calculate your power budget, *derate* your capacity to those of batteries being perhaps only 75-80 percent charged. This means that you have to buy even bigger capacity batteries than normal.

That's much more expensive compared to SLA lead-acid. But it may be worth it in the long run.

It comes down to this - unless you are skilled at maintaining a lead-acid battery properly, and TEST IT regularly for capacity, the LFP solution is far more reliable.

Along with LFP, I use some common 18-20ah sla batteries, but they are pampered. The bummer is keeping them topped off properly so that they aren't overcharged, but also aren't walking themselves down in capacity by not having that last 1-percent fully charged. (AGM's) If not, that repetetive 1-percent "walk down" occurs pretty rapidly. If it charges up fast, that 20ah battery may be a 10ah battery chemically inside now! That's not something you want to experience out in the field when EMCOMM becomes real, and not just a hobby piece of kit.

For me, that means Lithium, LIFEP04 in particular, when *properly* engineered to shield users from common charge/discharge mistakes, is the best bet for serious EMCOMM use. Again, derate your capacity (buy bigger batteries than you think you need) so that you aren't having them sit around fully charged for more than say 2 weeks at a time.

The biggest problem however is falling into the trap of building your own lithium / LFP battery bank with TOTAL GARBAGE cells hawked online and elsewhere. Commercial entities trying to pass off garbage is quite common. So stick to a reputable supplier / manufacturer.

 

[dorslv]

For EMCOMM use, my choice would be lithium. Why?

Most SLA batteries are murdered by their owners over time, with either overcharge or neglect. Many crappy battery chargers are available to help in this degradation process.

Lithium: Which one? LIFEPO4, (3.2v nominal) or the OTHER lithium batteries which are 3.7v nominal?

DONT EVEN THINK of using the 3.7v nominal batteries from Tesla's, Leafs, etc. Those are crash-victim batteries for one thing. And unless one is doing that already with the requisite skill and safety to do it properly - well, lets just say they aren't reading RadioReference.

Choose LFP, or lifepo4 which is far easier to maintain, (not to mention the ease of slapping 4 of them together to get to 13.8v nominal. OTHER lithium chemistries that are 3.7v nominal require more voltage regulation to accommodate. Slap 4 of the 3.7v varieties together and you have 14.8v nominal, which may be too much for your gear without additional regulation.

Non-lifepo4 - 3.7v nominal - varieties of lithium chemistries are smaller than lifepo4, but are much harder to maintain safely. The whole subject of LifeP04 and NON-lifepo4 truly can't be treated properly in this thread, so I'll stop.

Tip: when using LFP, or lifepo4 for EMCOMM use, do NOT store them at full charge forever! This means that when you calculate your power budget, *derate* your capacity to those of batteries being perhaps only 80 percent charged. This means that you have to buy even bigger capacity batteries than normal.

That's much more expensive compared to SLA lead-acid. But it may be worth it in the long run.

It comes down to this - unless you are skilled at maintaining a lead-acid battery properly, and TEST IT regularly for capacity, the LFP solution is far more reliable.

Along with LFP, I use some common 18-20ah sla batteries, but they are pampered. The bummer is keeping them topped off properly so that they aren't overcharged, but also aren't walking themselves down in capacity by not having that last 1-percent fully charged. (AGM's) If not, that repetetive 1-percent "walk down" occurs pretty rapidly. If it charges up fast, that 20ah battery may be a 10ah battery chemically inside now! That's not something you want to experience out in the field when EMCOMM becomes real, and not just a hobby piece of kit.

For me, that means Lithium, LIFEP04 in particular, when *properly* engineered to shield users from common charge/discharge mistakes, is the best bet for serious EMCOMM use. Again, derate your capacity (buy bigger batteries than you think you need) so that you aren't having them sit around fully charged for more than say 2 weeks at a time.

The biggest problem however is falling into the trap of building your own lithium / LFP battery bank with TOTAL GARBAGE cells hawked online and elsewhere. Commercial entities trying to pass off garbage is quite common. So stick to a reputable supplier / manufacturer.

Thanks for the great info, i've decided on a bioenno 12V, 12Ah LFP Battery w/charger which fits the battery case portablezero sells also the radio will be used mostly in the parks,( mainly because the H.O.A. police busted me with "wires" up in the trees ), maybe trails (possible knee surgery upcoming).

 

[nanZor]

I think that's a wise choice.

Go ahead and charge them up to full the first handful of times - that will help make sure that the entire surface of the materials are at their best potential and the SEI layer is fully developed.

After that, if you don't use them fully charged within 2 weeks or so, discharge them to say 80 percent of their capacity for longer term storage.

Ideally, they should be discharged to say 30-50% for long term storage, but that is impractical if you need to rely on them for EMCOMM for that first cycle when power isn't available.

The trick to LFP storage is a balancing act between fully charged degradation (sei layer buildup on the anode), and electrolyte-oxidation that occurs sitting around discharged.

The "mnemonic" I use for LFP is that they are quickly approaching discharge at 12.8v rested - just about where typical lead acid seems pretty healthy! Under light-load, I'll take them down to 12.5 to 12.6v or so before I consider them done. The BioEnno will do this for you for the most part, taking other considerations into account.

And of course, don't let them sit around nearly discharged either. 3.1v per cell storage is too low for long term.

It sounds harder than it is in practice. You'll be fine with BioEnno.

 

[mastr]

...consider the weight....a cooler full of beer, which would probably be much more welcome if the crap hits the fan...

Great idea. My "emcomm" battery solution from this point forward will be to display a cold 6 pack and loudly say "I'll trade this for a good, charged 12 volt truck battery".

 

[nanZor]

Don't forget the mini-fridge. That means keeping the truck battery healthy.

Whatever you do, please do not use a Schumacher speed-charger for normal maintenance as they have shown themselves to be too aggressive for batteries that aren't dead in the first place. If you chart the charging algo with the voltmeter placed on the *terminals* of the battery, this will often be very different from what is displayed in the panel. 15.5v is common during the absorb phase.

For normal batteries, this means that they are just gassing and not charging. Damaged batteries may actually gas-out, whereas normal batteries may just spin-their-wheels and not actually charge to full, before the safety timer kicks in.

My recommendation for maintenance, based on real-world monitoring with a lawn chair, voltmeter, chart recorder (West Mountain Radio CBA IV actually ... ) are these:

Tecmate-Optimate 5 / 6 / 7 (Use the 7 for Optima and Odyssey agm's with the 14.7v switch option) This is my main go-to. Well worth the price.

Tecmate-Optimate TM-500 DC-DC 2A charger. Uses a "donor battery" to charge your more important battery.

And, believe it or not, the Pulsetech XC-100. Despite all the marketing behind the pulse stuff (which you can safely ignore if you like), the underlying charge algo really does the job without harm.

In all cases, the post-charge (and during charge) diagnostics of all of these are trustworthy. If they say the battery is bad just stop wasting your time and start over with something else, or look for things like excessive parasitic draw, etc.

There are zillions of vehicular chargers that just get it wrong during the critical end-game of charging. Many are either too conservative, relying on the next vehicular charge to actually finish it, or like in the case of the speed-chargers, too agressive. It would almost be better to not use some vehicular chargers / maintainers at all if they don't get the end-game right. Especially harmful are the agressive chargers that can really do a number on freshly-made batteries that don't even have a handful of cycles on them to prime the plates.

The problem is that discussing battery chargers is like discussing oil-additives. There's no end to the marketing claims vs real-world.

WARNING - know the difference between a charger and a maintainer depending on the capacity of your battery! Using a low amperage maintainer to try and fully charge a huge dead truck battery is not recommended - some manufacturers even warn about this, so don't put a wall-wart on a dead $350 truck battery. Maintenance - fine. Bulk / vehicular charge it a bit first. And don't expect miracles nor blame the charger if you are starting out with trashed / internally damaged batteries to begin with. You may revive them to a zombie-like state, but other than doing that for fun, stop wasting time and start fresh.

So that's my 2c. For lead-acid maintenance, I don't have the time to do it all manually with my programmable bench supply, as much as I enjoyed it (where battery charging becomes a hobby all unto itself).

TIP: all SAE vehicular charger connectors suck. Some are better than others. Swapping different oem cables can be a problem too as the connectors aren't always the best fit with each other, even though the *feel* ok.
At the very least, exercise the sae connector a few times after purchase, and once in awhile later on down the road. Better yet, chop em out and use large gauge Anderson Powerpoles. Exercise them once in awhile too.

For me, the Tecmate-Optimate 5/6/7 series, and the Pulsetech play smarter chess than the rest, and should help keep the beer in the mini-fridge during an EMCOMM event cool!