12 Volt Lead-Acid Battery + Trickle Charger to Power Base-Station Mobile Transceiver?

[chiwititsara]

My 12 volt (variable, adjusted to ~13.5v) DC switching power supply just died. I had been using it to power a small 10 watt 2 meter mobile radio for an indoor base station.

I have a few 12 volt starting and deep-cycle lead acid batteries lying around. I also have a spare Battery Tender Jr (0.75 amp max output, seems to float attached battery around 13.4 volts).

This radio consumes well under 1 amp on standby. I rarely transmit or receive but use this radio for occasional simplex contacts.

Would there be any problem running my radio from a 12 volt battery (inside an appropriate battery box) that is also connected 24/7 to the trickle charger?

 

[k6cpo]

You sholdn't have an issue as long as the battery is in good condition. I have a pair of 12V SLA batteries wired in parallel as back up power for my station consisting of two 50W mobiles and a 100W iCom HF radio. I can run the radios off the batteries with the charger still hooked up without issue.

 

[mmckenna]

My 12 volt (variable, adjusted to ~13.5v) DC switching power supply just died. I had been using it to power a small 10 watt 2 meter mobile radio for an indoor base station.

I have a few 12 volt starting and deep-cycle lead acid batteries lying around. I also have a spare Battery Tender Jr (0.75 amp max output, seems to float attached battery around 13.4 volts).

This radio consumes well under 1 amp on standby. I rarely transmit or receive but use this radio for occasional simplex contacts.

If the radio pulls more than the 0.75 amps that the battery tender supplies, it'll eventually drain the battery all the way down. Draining batteries all the way down to nothing is a good way to destroy them.
If you do not keep the radio on all the time, and can manage the draw versus supply issues, then it might work.

Would there be any problem running my radio from a 12 volt battery (inside an appropriate battery box) that is also connected 24/7 to the trickle charger?

I would check to see how pure the DC supply is from the battery tender. If it's noisy, that's going to come across in your audio. These battery tenders are not designed for communications type use, so may not have appropriate filtering.

You could absolutely use the battery tender to charge the battery when the radio is off, and just disconnect it when you want to use the radio.

Periodically check the battery/tender. Those things have been known to fail and either not charge the battery, or over charge it. As with any lead acid battery, you need to be careful about over voltage and the battery outgassing hydrogen.

 

[WA8ZTZ]

Do not charge or use an automotive lead-acid battery indoors.

 

[majoco]

It's all very well to make such a statement, but could you please give reasons or a source.

 

[G7RUX]

It's all very well to make such a statement, but could you please give reasons or a source.

Wet cell lead-acid batteries produce hydrogen gas (and oxygen but that's not the issue) when charging so doing this indoors can be somewhat hazardous, for reasons related to the Graf Hindenburg.

 

[WA8ZTZ]

It's all very well to make such a statement, but could you please give reasons or a source.

The primary concern is hydrogen gas. Too many possible sources of ignition... electrical spark, static electricity, cigarette, pilot light, space heater, etc. Too easy to put the battery on a charger and get distracted with something else, forget about it, fall asleep, or whatever and all the while the battery is gassing. Even the so-called "maintenance free" batteries have vents. The case may rupture without a fire, but there will still be sulfuric acid spewed all over.

 

[majoco]

Much better, thanks. As a retired aircraft engineer and also an ex marine radio officer I knew that of course. All ships back in the 60's had a bank of batteries in a vented box on the deck outside the radio cabin which had to be inspected once a week for fluid levels and specific gravity of every cell measured - an entry had to be made in the radio log and the ships log that this had been carried out as it was part of the ships emergency equipment.

 

[G7RUX]

Much better, thanks. As a retired aircraft engineer and also an ex marine radio officer I knew that of course. All ships back in the 60's had a bank of batteries in a vented box on the deck outside the radio cabin which had to be inspected once a week for fluid levels and specific gravity of every cell measured - an entry had to be made in the radio log and the ships log that this had been carried out as it was part of the ships emergency equipment.

This practise continued into the 90s when the radio requirements for ships at sea changed (for the worse) and R.O.s became a thing of the past.

 

[TGuelker]

As an apprentice (now retired) mechanic, I had a car battery blow up about a foot from my face. I had it on a boost charger and smelled the battery gassing. The battery was hot to the touch. Instead of turning tne charger off THEN disconnecting the charger from the battery, I grabbed one of the leads and yanked it off. What happened next is foggy. I remember the BOOM and that another tech was blasting my face with the shop water hose.
Whole top of the battery was embedded into the hood insulation. Fortunately, I was not hurt. My looks are due to genes, not battery acid. Unfortunately, the customer was watching from the waiting room. He insisted we buy him a new battery. Boss said it wasn’t worth explaining chemical reactions.

I would use a gel cell battery instead of a lead acid battery.

 

[prcguy]

With the title of this thread including the words "trickle charger" I would not worry about excessive battery outgassing or explosions. The charge current of a trickle charger is about 1A and I've never seen a battery outgas or heat up or do anything when connected to a trickle charger. I would however keep an indoor lead acid battery in a portable plastic battery box to protect the area from sloshing or spills.

 

[KK4JUG]

With the title of this thread including the words "trickle charger" I would not worry about excessive battery outgassing or explosions. The charge current of a trickle charger is about 1A and I've never seen a battery outgas or heat up or do anything when connected to a trickle charger. I would however keep an indoor lead acid battery in a portable plastic battery box to protect the area from sloshing or spills.

While you're probably right, I don't think I'd take a chance.

 

[NA9X]

Using a 12v battery will power the radio, but if you plan on transmitting, the voltage can drop. It probably won't cause issues with the 10watt radio you mentioned but with higher power transceivers it can affect the waveform on transmit. When voltage drops below 11.8 or so, the radio may shut down or behave oddly. For my battery backup system, I use four 6v golf cart batteries wired in series for 24v and leave them in my garage where I am more comfortable charging them. From there, wire feeds 24v to the shack and a step-down converter for a constant 13.8v output with much less voltage drop on transmit.

 

[W8WCA]

Here are just a few sources on Lead Acid Battery Charging

https://ehs.umass.edu/sites/default/files/Battery%20SOP.pdf

https://www.ehs.wvu.edu/files/d/0c032a15-ce2c-49b8-8d44-2d6391af0335/lead-acid-battery-safety.pdf

Vehicle Battery Charging Safety

Club cars can present hazards during charging. Follow these steps to ensure safe maintenance of electric carts and utility vehicles. Departmental electric golf carts, club cars and utility vehicles can be incredibly useful to travel and transport items across campus. However, that convenience...

ehs.princeton.edu

 

[W5RGP]

Do not charge or use an automotive lead-acid battery indoors.

ITS OK TO USE SEALED LEAD ACID INSIDE

 

[NA9X]

ITS OK TO USE SEALED LEAD ACID INSIDE

Many UPS's available commercially do actually have sealed lead acid batteries inside the unit, so with their charging systems in the factory installed arrangement, the risk is apparently mitigated. However, I would not recommend a charging a flooded wet acid battery be charged indoors in the same manner - they are not the same. I have LiFePo4 batteries I would be more comfortable charging inside my house but not flooded lead acid batteries. JMHO

 

[wtp]

while it might be OK to have an acid battery inside, i also would not take the chance.
there are other options now.
i used to use an acid battery for CB use, but charged the battery weekly on the garage floor. the CB was just to listen.