R8600 Can the IC-R8600 be connected directly to a Sealed Lead Acid Battery

[AOR-262]

I'm using the supplied Icom AD-55 PSU to power my IC-R8600. There has been some discussion that this PSU is a 'switching' PSU that causes some RF noise that the receiver picks up. If I tune my AOR 8600 Mk2 to a frequency of 0.909 kHz AM (my AOR and Icom sit side-by-side) the interference from the Icom PSU is really strong -- however, if I turn off the Icom PSU, on the AOR there now becomes no interference at all on any Long Wave, Short Wave, Medium Wave bands etc.

The 8600 comes with a power cable that is designed to be used to connect the receiver to a dedicated PSU. So I was wondering, can the 8600 be connected directly to a 12v 2.1AH Sealed Lead Acid Battery -- or would I need some sort of 'something' in-between to regulate/control the power from the battery so that for example there's no surge of power that would cause damage to the 8600.

Would I be right is saying a battery wouldn't cause any 'switching' noise or generate RF Interference?

So, is it ok to connect the 8600 directely to a battery?

This is what I am considering getting ...

https://www.screwfix.com/p/sealed-l...ah/20080#product_additional_details_container

 

[kruser]

I'm using the supplied Icom AD-55 PSU to power my IC-R8600. There has been some discussion that this PSU is a 'switching' PSU that causes some RF noise that the receiver picks up. If I tune my AOR 8600 Mk2 to a frequency of 0.909 kHz AM (my AOR and Icom sit side-by-side) the interference from the Icom PSU is really strong -- however, if I turn off the Icom PSU, on the AOR there now becomes no interference at all on any Long Wave, Short Wave, Medium Wave bands etc.

The 8600 comes with a power cable that is designed to be used to connect the receiver to a dedicated PSU. So I was wondering, can the 8600 be connected directly to a 12v 2.1AH Sealed Lead Acid Battery -- or would I need some sort of 'something' in-between to regulate/control the power from the battery so that for example there's no surge of power that would cause damage to the 8600.

Would I be right is saying a battery wouldn't cause any 'switching' noise or generate RF Interference?

So, is it ok to connect the 8600 directely to a battery?

This is what I am considering getting ...

https://www.screwfix.com/p/sealed-l...ah/20080#product_additional_details_container

Yes, you can run the 8600 directly from any external 12 volt DC source. Just pay attention to voltage if you are also charging the external battery at the same time you are running the 8600 from it. And if so, use a linear power supply to keep the SLA at the correct voltage otherwise that charger or power supply may cause the same RFI as Icom's AD-55 does!

I run all my radios off of a large bank of SLA batteries with an external 30 amp power supply which keeps the SLA's topped off at 13.8 VDC. I had to play with current regulation some so the SLA's would not see a high charge current if power was lost and restored while I was not home. I used a home built design the limits the output current to whatever I set it at.

The 8600 can actually accept a fairly high voltage level at its input so you should be safe in most cases. I think I read the AD-55 can put out near 19 volts which was found to make the 8600 run warmer than normal by many owners that watch these things.

Read the specs in the manual, I think the input voltage must be within 15% of the rated supply voltage so any external source within 15% should be fine.

 

[Ubbe]

No problem between 8600 and battery but the power supply needs to have a fixed maximum voltage level to not overcharge the battery. Measure the PSU voltage unloaded and if's 15volts or over it is probably unregulated as well and cannot be used. If the voltage are lower you could probably open up the PSU and make adjustments, if neccesary, so it will not go over 14 volts.

/Ubbe

 

[AOR-262]

Thanks all -- I've gotten the information from you all I need. More importantly, none of you said not to connect the 8600 directly to the battery for whatever reason. Once the battery was flat, I'd disconnect the cables to charge the battery so there wouldn't be any danger of the battery charger damaging the 8600 -- although the charger I have is a smart charger that only outputs 12v @750mAh -- it may take a few days to fully charge the battery but that's ok.

Just out of curiosity, if I bought a car battery that was rated at the following spec.:

12v
CCA SAE 530 Amps
AH (20h) 55 Amps

Would that battery with those voltage/amperage be ok for direct connection?
And also, could I then run my IC-R8600 and AOR 8600 Mk2 both from the same battery?

 

[kruser]

No problem between 8600 and battery but the power supply needs to have a fixed maximum voltage level to not overcharge the battery. Measure the PSU voltage unloaded and if's 15volts or over it is probably unregulated as well and cannot be used. If the voltage are lower you could probably open up the PSU and make adjustments, if neccesary, so it will not go over 14 volts.

/Ubbe

That's what I do Ubbe, I adjust my external supplies output voltage to 13.8 VDC max in many cases.
That way if the mains power goes out when I'm not home, the external supply will not exceed 13.8 VDC upon restoration of mains power from the utility company.
While this works, it does still leave the problem of dumping way too much current into the bank of SLA's depending on how low they discharged while mains power was out. Some supplies have internal current monitoring and that circuit can be used to regulate the charging current to say 2 amps or whatever you need. If a supply does not have current regulation, I add it as I don't want my SLA's seeing 30+, amps of charge current applied to them if I'm not home. It can be an easy circuit to add depending on how large your external supply is.
One can also use some type of "ballast" resistor to limit the charge current into the SLAs.
I've used 12 volt aircraft landing lights to do this in the past. While that can work, it can also not work perfectly as the load presented to the SLA will change with what is turned on when mains power is restored.
Ideally, I like to keep my charge current set to no more than 50% of whatever the SLA manufacturer recommends for charge current.
I'll also adjust my charge current limit to maybe an amp or two above whatever the connected devices can draw. This limits the charge current to the SLAs but being slightly above the current requirement, it still allows the SLA's to charge unattended if I'm away during a loss of mains power.

I don't worry too much about battery cell damage if I'm not charging them fast or high enough. I err on the side of safety over maximizing battery life unless I happen to be using some highly expensive SLA batteries. Some of these SLAs like to see a charge voltage of 14 VDC or more before being allowed to taper back off to a maintenance voltage of usually 13.8 VDC. That is the one I normally don't worry much about. I could care less if I reduced my battery life by 6 months because I did not bring it back up to 14 VDC or more before allowing it to taper back off to 13.8 VDC when the charge is complete. I'd much rather see this than chance a fire because a cell decided to fail when charge voltage was restored!
I've also installed temperature sensors above my banks of SLA cells at times. If the temperature is exceeded, it is most certainly due to a cell that is overheating because it has failed in some fashion. My sensor will simply kill power to the charging supply but they can also be configured to dump the load from the batteries as well.
If I'm really worried about something because I'm working with high amperage values, I'll add temp sensors on each cell to catch this overheating condition and kill power or load to/from the SLA. Usually though, I simply measure the temp of the space directly above the SLAs much as a home smoke alarm works to sense fire in a home but I'm just watching the space or area my SLA's are located.
It may be over complicated but it does work, especially when you are working with some really high amperage's like several SLA's can produce depending on how they are wired.

 

[kruser]

Thanks all -- I've gotten the information from you all I need. More importantly, none of you said not to connect the 8600 directly to the battery for whatever reason. Once the battery was flat, I'd disconnect the cables to charge the battery so there wouldn't be any danger of the battery charger damaging the 8600 -- although the charger I have is a smart charger that only outputs 12v @750mAh -- it may take a few days to fully charge the battery but that's ok.

Just out of curiosity, if I bought a car battery that was rated at the following spec.:

12v
CCA SAE 530 Amps
AH (20h) 55 Amps

Would that battery with those voltage/amperage be ok for direct connection?
And also, could I then run my IC-R8600 and AOR 8600 Mk2 both from the same battery?

Yes, this could work. One issue may be the fact that car batteries are not really designed like an SLA or deep discharge battery is so running them flat or down to a really low voltage will usually damage the battery and greatly shorten its life really fast.
Circuits can be built to monitor and disconnect any load on the battery if it does drop below a set level though. This can save them from discharging below the safe limit and prevent an early death of your battery.

The other main thing to keep in mind if you are doing this indoors, you also must keep the fact in mind that there will likely be explosive gasses present when using any type of flooded wet cell battery like a car battery. These gasses are hidden but can carry a very bad punch and could burn your house down or result in death.

SLA type batteries are often used as they produce much less explosive gasses when compared to a standard flooded wet cell car battery. Those sold as deep discharge types for say trolling motor use may prevent low voltage from damaging them but if they are the flooded cell design, you still risk creating an explosive atmosphere while charging or during heavy discharge periods.
You are better off using SLA's of the size you need if you ask me. It's better to be safe than sorry.
With the variety of batteries available today, I'd not recommend using any type of car battery as there are much safer alternatives available.

 

[AOR-262]

Yes, this could work. One issue may be the fact that car batteries are not really designed like an SLA or deep discharge battery is so running them flat or down to a really low voltage will usually damage the battery and greatly shorten its life really fast.
Circuits can be built to monitor and disconnect any load on the battery if it does drop below a set level though. This can save them from discharging below the safe limit and prevent an early death of your battery.

The other main thing to keep in mind if you are doing this indoors, you also must keep the fact in mind that there will likely be explosive gasses present when using any type of flooded wet cell battery like a car battery. These gasses are hidden but can carry a very bad punch and could burn your house down or result in death.

SLA type batteries are often used as they produce much less explosive gasses when compared to a standard flooded wet cell car battery. Those sold as deep discharge types for say trolling motor use may prevent low voltage from damaging them but if they are the flooded cell design, you still risk creating an explosive atmosphere while charging or during heavy discharge periods.
You are better off using SLA's of the size you need if you ask me. It's better to be safe than sorry.
With the variety of batteries available today, I'd not recommend using any type of car battery as there are much safer alternatives available.

That's a good point kruser. I never thought about 'deep discharge'. I guess I would be fully charging the battery and running the 8600 from it until the battery died and then slow/trickle charge the battery until full. I'm toying with the idea of the small 12v 2.1A battery more than considering getting a full-size car battery. I think the main application use for the small battery is a backup battery for home burglar alarms. I need to find out the capacity of that small battery first. As long as it would give me say 2/3 days use that would be ok. After what you said about deep discharge; I guess you mean regular use and that would be the 8600 drawing around 2A during normal operation, I would probably not use the battery as my main power source -- just use it a few times a week.

 

[AOR-262]

Yes, this could work. One issue may be the fact that car batteries are not really designed like an SLA or deep discharge battery is so running them flat or down to a really low voltage will usually damage the battery and greatly shorten its life really fast.
Circuits can be built to monitor and disconnect any load on the battery if it does drop below a set level though. This can save them from discharging below the safe limit and prevent an early death of your battery.

The other main thing to keep in mind if you are doing this indoors, you also must keep the fact in mind that there will likely be explosive gasses present when using any type of flooded wet cell battery like a car battery. These gasses are hidden but can carry a very bad punch and could burn your house down or result in death.

SLA type batteries are often used as they produce much less explosive gasses when compared to a standard flooded wet cell car battery. Those sold as deep discharge types for say trolling motor use may prevent low voltage from damaging them but if they are the flooded cell design, you still risk creating an explosive atmosphere while charging or during heavy discharge periods.
You are better off using SLA's of the size you need if you ask me. It's better to be safe than sorry.
With the variety of batteries available today, I'd not recommend using any type of car battery as there are much safer alternatives available.

As a way of some information, the battery I was considering getting is ideal for Float or Cyclic applications -- I didn't know what Float or Cyclic meant until I read this ...

Standby & Cyclic definitions - Yuasa

 

[Ubbe]

Equipments usually have a natural deep discharge protection as they hardly take any current at all if the voltage drops to a very low level.
But simplest protection are a 12 volt relay over the battery terminals and when engaged will close the circuit between battery and equipment. When the battery voltage drops to something like 9 volts the relay will release it's contacts and cut the connection from the battery. The relay then only draws some 10mA that wouldn't discharge the battery. You could add a low value resistor in series with the relays coil to make it cut off at a higher voltage and have a momentary switch that bridge the resistor when you want to power the equipment again when the charger have raised the voltage high enough to generate a proper start up process.

/Ubbe

 

[kruser]

That's a good point kruser. I never thought about 'deep discharge'. I guess I would be fully charging the battery and running the 8600 from it until the battery died and then slow/trickle charge the battery until full. I'm toying with the idea of the small 12v 2.1A battery more than considering getting a full-size car battery. I think the main application use for the small battery is a backup battery for home burglar alarms. I need to find out the capacity of that small battery first. As long as it would give me say 2/3 days use that would be ok. After what you said about deep discharge; I guess you mean regular use and that would be the 8600 drawing around 2A during normal operation, I would probably not use the battery as my main power source -- just use it a few times a week.

Deep discharge would be what could occur if the power goes out while you are using the battery as a power source and don't have some external power to keep it charged. I forget but I think any storage voltage below around 11.7 volts or so can damage an SLA or most wet cell batteries (like car batteries) if left sitting like that for an extended period of time. They self destruct internally in simpler terms! I think it is called "sulfating". This damage will not occur immediately so you are still safe but you don't want to leave a battery sitting at low voltage for an extended period of time. I don't recall a safe amount of time before the sulfating takes a permanent toll on the battery. Days or weeks etc, I can't remember. I just try and not leave my batteries like this for any longer than it takes to complete my tests. Of course it's out of my control if power is lost due to a really bad storm and I'm not home to remove the loads! I do have some setups that automatically remove all loads when the voltage drops below a certain level but not all have this protection on them. Only those with a decent amount of money invested in the batteries have I included this circuit.

Most SLA and other wet cell type batteries should be kept above 12 volts while sitting on the shelf in a storage condition.

I agree that it sounds like you will be better off using a smaller sized battery to keep the 8600 running for the time you need if commercial power goes out. The charging circuit will be simpler as well.
I know that a 2.5 something AH battery will definitely not run the 8600 for anywhere close to 2 or 3 hours though. You probably need an SLA with more of a 30 to 50 AH rating to come close to that time requirement. There are battery size calculators online but they are only as accurate as the data you feed them! It seems like a lot of battery size data is way off these days depending on the source of info.

I honestly forget how much runtime I can get from one of my SLA setups. I'm thinking I can average in the 8 hour range if not mistaken though.
For this one, I'd be using two 33 AH SLA batteries wired in parallel and kept at a constant 13.8 VDC charge voltage at all times unless power goes out.
This one is used to provide power to two 8600's and one or two BCD536HP's. I could be thinking of one of my other battery setups but I'm pretty sure these specs are the one I'm thinking of. If correct, the last time I ran a runtime test, I got somewhere around 8 hours of use from it before one of the radios started yelling about low voltage. I could very easily be thinking of a similar setup that only uses one 33 AH battery also. I have four battery backup setups here and I seem to confuse them pretty often!

 

[kruser]

As a way of some information, the battery I was considering getting is ideal for Float or Cyclic applications -- I didn't know what Float or Cyclic meant until I read this ...

Standby & Cyclic definitions - Yuasa

Some good info here. Basic but generally good! Kind of gives you the idea behind the theory really.

I've used this companies batteries several times. Never had any problems with them. I think they are regarded by many as a quality battery but I don't know if that applies to all their chemistries they sell or just some.
Thanks for the link, I don't recall ever reading this one before!

 

[nanZor]

A cheaper and most likely noise-free replacement power supply may be the better answer. The 8600 draws 2A at max volume, so lets use that. At power on, spikes larger than 2A might temporarily occur, so perhaps a linear power supply, like an ASTRON 7A might be a better replacement.

SLA: If you still want to go the SLA route, we'll still use the 2A maximum power draw for the math to give us some headroom. I doubt you'll be blasting it, but lets go worst case ...

To get any sort of cycle-life from an agm/sla battery, one usually doesn't want to draw more than 50% of the capacity from it each cycle. Less draw is even better, but for now we'll push it:

If you want to run the 8600 for 12 hours straight, that means you'll be pulling 24ah. (12h * 2A). Because we don't want to draw more than 50% of the capacity per cycle, for a 12 hour operating period, that means you'll need a fully charged 24ah capacity sla.

Scale the above for your operating time needs to determine the capacity you'll need vs time.

Tip: While operating, don't let the battery get below 12.2v, with 12.0v max. (easy to remember). The lower voltages, like 10.7 / 11.7v that inverters and other devices kick out at, are a *dead man* battery saver. That is, at those low voltages, the battery is considered 100% discharged. You don't want to do that, unless you like getting only a small handful of cycles.

Vehicle batteries, AND the typical small AGM batteries: Both generally have thin plates, putting them into the SLI (Starter Lights Ignition) category, and while you CAN deep discharge them just a few times, they are really meant to not be discharged any more than 10 - 15% each cycle - that is if you want them to last for years.

So, that means if you were to purchase a 55ah vehicular agm, then you really don't want to pull more than 5.5 to maybe 10ah out of them each cycle. Since the 8600 draws 2A max, then that huge SLI battery should not be discharged more than about 5 hours max each charge cycle.

Or just discharge more, but get less cycle life.

THIS is why I say an small linear-model Astron supply would be cheaper in the long run, despite how much fun I like using batteries for my gear.

P.S. The 2.1ah battery you mentioned earlier would NOT power the 8600 for one hour, despite it's rating. That's not how it works, as amp-hour capacity ratings are based on a 20-hour discharge! What this means is that as soon as you powered on the 8600 with that battery, the voltage would immediately drop with such a heavy load that the 8600 would turn off rather quickly with undervoltage.

Real-world worst-case with agm's: Never discharge faster than 0.25C (one quarter of it's ah rating), nor charge it faster than that either. Charging a pure-lead like an Optima or Odyssey is a different $tory.

 

[AOR-262]

@hertzian Thanks for that reply. That is some good information. Much appreciated for your reply.

 

[majoco]

Camper vans that have 'house' batteries as well as the normal vehicle batteries are often 'deep cycle' batteries. Deep cycle batteries, like gel-cell batteries do not like going down below 1 volt per cell and therefore have a 'low voltage disconnect' device. If you are listening when the power goes off and subsequently your 'low voltage disconnect' device kicks in, then I suggest you may have more things to worry about in your house rather than the radio not working! ou will need some form of protection to stop the battery discharging back through the power supply when then power is off. When the power does come back on, you need some current limiting and a resistor will do just fine - I have used a car brake light in the past, it will pass about 2.5 amps into a short from 13.8 volts but as soon as the battery volts start to rise the current will drop off - and of course when the battery gets to 13.8 volts the charge current will just be a maintaining voltage.