Battery Backup

[Savage]

Yeah they are for my fridge/freezer and some led lights that came with the kit. I use a cheap 10ah battery on a charger for my gmrs mobile base radio. I also have a 12v power supply which runs my cb currently but I can just tie that in to the battery if the power goes out.

 

How much life does the 10ah battery give your base?  I keep getting drawn into thinking I need 100ah or more.  

[FrancisHaws]

How much life does the 10ah battery give your base? I keep getting drawn into thinking I need 100ah or more.

Probably several days but I always put it on the charger at night so I can't say for sure. For example, today my btech 50x1 was on it all day scanning and I transmitted for maybe 30 mins total on high power (50 watts) and it never dropped below 14.1 volts. The radio needs a minimum of 13.8 so I figure under normal use I can get several days out of a single charge. I also have 2 large deep cycle batteries from my trolling motor that I keep hooked up to a 100w solar panel so in the worst case scenario I have that to fall back on. The small battery I use for my station is the 10ah harbor freight one for their electric start generators. It's smaller than a lawn tractor battery and easy to transport so that is why I use it. I think a regular size car or truck battery and a small solar panel would be more than enough to keep you on the air 24/7 as long as you you aren't rag chewing the whole time

[dwmitchell61]

If you don't need the meters, this is the model without them. https://www.toboaenergy.com/product/samlex-sec1235-switching-power-supply/?_vsrefdom=adwords&msclkid=7e73c0b058a31f4ec5f49f244919dfc7&utm_source=bing&utm_medium=cpc&utm_campaign=**LP%20Shopping%20-%20Electrical%20Switches&utm_term=4582352148614327&utm_content=woocommerce_gdf_12563%20%7C%20Samlex%2030%20Amp%20120vAC-13.8vDC%20Switching%20Power%20Supply%20%7C%20%24156.8

 

If you don't need the 100A capacity, you may like this: https://www.toboaenergy.com/product/samlex-bbm-1225-battery-back-up-1224v-25amp-charger/

I always over-engineer... It allows for later expansion without buying EVERYTHING all over again. If you don't plan on doing anything but the one radio, by all means, go as light as you can.

[BoxCar]

Personally, I think you are way over engineered. I would look at other supplies such as some of the inexpensive Chinese ones. I'm running a 30A no name that's designed for communications work and paid less than $25 for it. If you want a good Chinese one, look to Mean Well. Their supplies are a little more than what I paid but have a great rep. My little cheapie has millivolts of ripple, so little I can't measure it accurately with my cheap Harbor Freight meter.

[WRCN255]

On 10/15/2020 at 8:11 PM, Savage said:

So I got to thinking... I've got a gas generator but in an emergency, I'm not going to want it running 24/7.  What are you guys doing for battery backup to power your base station (I'm guessing repeater backups are much more complicated)?

 

APC UPS?  Something else?  I'm not so concerned that the radio stays on if the power goes down as much as a means of running the radio for a time, perhaps recharging the batteries with the generator or hooking it up to a solar panel.

 

 

I have a 50ah backup battery inline with the power module. The power supply keeps the battery floating, then the battery actually powers the radios.

[WSFF627]

Lots of good options have been discussed here. All work relatively well. For a base radio, pretty much any 12 volt battery will work. Keep in mind that TX power can vary greatly with battery voltage. 1-2 volts can mean the difference between 35 watts and 50 watts, depending on the radio. Granted, this is only a couple of dB, but those may be the dB's you need. Battery power for base radios can be pretty easy, and all the options above are pretty good and will work for your application.

Repeaters are a different story, while you control the use of your radio, repeater use can vary quite a bit and be a lot more demanding. A typical radio is built to TX with a 20% duty cycle, a repeater is built for a 100% TX duty cycle.  I run a 50 watt GMRS repeater with a large footprint, a 100 watt 70cm HAM repeater, and a remote RX station for a very large 70cm HAM repeater out of my "repeater shack". The GMRS and remote RX are Kenwood TKRs which run on 13.8vdc, the GMRS has an amp for duty cycle at 100%, and both are running pre-amps at 13.8vdc. The power supply for them is a Astron 50amp with built in battery backup. Its battery backup is 12vdc.  The 100 watt 70cm repeater is Motorola MTR3000 (100% duty cycle at 100 watts), which requires 28vdc and a battery reverting charger (its also equipped with a pre-amp that its built in supply handles). Battery capacity is sized to run the repeaters under full power with moderate usage for at least 24 hours before they have to transfer to an inverter generator (regular alternator generators produce very dirty power).  Its essential the 70cm remote RX stays on the air because its part of the SKWARN network. The other HAM repeater may join it in SKYWARN service in the future, likely in digital or mixed mode. Its also pretty important the GMRS repeater stays on the air because users have expressed they want and or need it for emergency comms with family and friends. Currently I have to transfer power to generator manually, but I'm planning an auto start and ATS project for that so its all auto.

The best power / battery backup option for you is one that works for you and costs what your willing to spend on it. 

[WSEZ864]

I've been lucky to have a friend in IT that services corporate computer systems. They are always having UPS units dying off, most of the time due to one 12v9ah battery in a bank of four going bad. Most mid-size UPS units have a two (12ah) to four (9ah) battery pack that is replaceable, but often costs almost as much as a new UPS. The corporations typically just want to replace the entire dysfunctional UPS rather than making internal repairs, so my buddy just swaps them out and saves the bad ones for me.

I check them out and once in a while can make a repair, but usually just strip the batteries out, test them and dump the bad battery. As a result, I have couple working UPSs laying around, plus about 175ah capacity in small 12v batteries, mostly 9ah I've scavenged, but also a few 18-22ah batteries I've bought.

About once a month I'll rotate the individual batteries through a quick charge and top them off by plugging them into my bench power supply as I run radios. Most stay near 12.8v between charges, but as soon as I see one go below 12v, I know it's on it's way out.

[WRYZ926]

Those 9 -10 ah UPS batteries work well for 20 watt and QRP radios. 

Expert Battery/ECI batteries ar good and reasonably priced on eBay. You can get  12v 10ah lead acid battery for $27.49 or a 12v 10 ah lifepo4 battery for $38.99. One guy has been using the ECI lead acid 12v 10 ah batteries for his QRP radios for years. I use the lifepo4 versions for my Xiegu G90, Wouxun KG-XS20G and my WRP radios. 

ExpertBattery 12V 10AH Battery

2500+ Cycles Rechargeable 12V 10Ah LiFePO4 Lithium Iron Phosphate Battery

I know buying replacement batteries from the UPS manufacturer are expensive and close to the cost of a new UPS system.