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Battery back-up system for multiple rigs

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N2TK

Battery back-up system for multiple rigs

Looking for some advice. Trying to help out a friend who is setting up an
emergency communications system for the Hams in their condo group.

They have several marine batteries they want to tie in parallel so they can
run multiple rigs, K3's plus UHF/VHF for extended periods. They have a
charger for the batteries. They use the 12V off the batteries to a
distribution box for the 12V equipment.

Questions:

- What is the best way to isolate the equipment from the batteries
if something happened to the battery (ies).

- Is there a way to isolate the batteries from each other if
something happened to one battery so it didn't draw down the other
batteries?

- Am I missing anything else that should be done for safety of the
equipment, batteries and the operators?

Tnx

N2TK, Tony

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Joe Subich, W4TV-4

Re: Battery back-up system for multiple rigs

Tony,

I'd start by building one of these "powergate" modules for each battery
and connect the Station Equipment terminals in parallel:
<www.nfarl.org/kits/powerGate/Power_Gate_Assembly_Instructions_v2.pdf>

Alternatively, you can use the design approach with appropriately sized
individual Schottkey diodes mounted to heat sinks for each battery or
power supply. In essence you want the low Vf drop diodes to isolate
the batteries and power supplies from each other in case of a failure
of any one device.

One could build more complex circuits using relays or power FETs to
disconnect the batteries when mains power is available but the diode OR
circuit with the mains power supply set to 14.8V provides full supply
power while "on mains" and suffers minimum (~0.4V) voltage drop in
battery voltage in "back-up" mode. If one is anal about having exactly
13.8 V for the rig, one can even add a boost/buck regulator for each
rig (or group of rigs in the case of the VHF boxes).

73,

... Joe, W4TV
Any opinions express here are my own and are not representative
of Elecraft, any other amateur manufacturer, or organization.

On 2015-01-22 2:47 PM, N2TK, Tony wrote:

> Looking for some advice. Trying to help out a friend who is setting up an
> emergency communications system for the Hams in their condo group.
>
> They have several marine batteries they want to tie in parallel so they can
> run multiple rigs, K3's plus UHF/VHF for extended periods. They have a
> charger for the batteries. They use the 12V off the batteries to a
> distribution box for the 12V equipment.
>
>
>
> Questions:
>
> - What is the best way to isolate the equipment from the batteries
> if something happened to the battery (ies).
>
> - Is there a way to isolate the batteries from each other if
> something happened to one battery so it didn't draw down the other
> batteries?
>
> - Am I missing anything else that should be done for safety of the
> equipment, batteries and the operators?
>
>
>
> Tnx
>
> N2TK, Tony
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]
>

Elecraft mailing list

Re: Battery back-up system for multiple rigs

If I read the question correctly, the need is to provide a what if protected system of power delivery. Well, if the system design can handle the load for a "period" of time, say 8 hours. The simple and easy solution is to have several of the same battery sources on independent standby and just switch them in as needed. No complex charging,protection, isolation systems required. If one fails it will not affect the others. The independent battery smart chargers at <$50. Use knife switches and your are a go. Thats what I have.. KISS. approach. What say you????
Mel, K6KBE

From: "Joe Subich, W4TV" <[hidden email]>
To: [hidden email]; "N2TK, Tony" <[hidden email]>
Sent: Thursday, January 22, 2015 12:21 PM
Subject: Re: [Elecraft] Battery back-up system for multiple rigs

Tony,

I'd start by building one of these "powergate" modules for each battery
and connect the Station Equipment terminals in parallel:
<www.nfarl.org/kits/powerGate/Power_Gate_Assembly_Instructions_v2.pdf>

Alternatively, you can use the design approach with appropriately sized
individual Schottkey diodes mounted to heat sinks for each battery or
power supply. In essence you want the low Vf drop diodes to isolate
the batteries and power supplies from each other in case of a failure
of any one device.

One could build more complex circuits using relays or power FETs to
disconnect the batteries when mains power is available but the diode OR
circuit with the mains power supply set to 14.8V provides full supply
power while "on mains" and suffers minimum (~0.4V) voltage drop in
battery voltage in "back-up" mode. If one is anal about having exactly
13.8 V for the rig, one can even add a boost/buck regulator for each
rig (or group of rigs in the case of the VHF boxes).

73,

... Joe, W4TV
Any opinions express here are my own and are not representative
of Elecraft, any other amateur manufacturer, or organization.

On 2015-01-22 2:47 PM, N2TK, Tony wrote:

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ke4rg

Re: Battery back-up system for multiple rigs

In reply to this post by N2TK

I use the Astron BB-30M for shack and RV. This is the 30A version, but they
make larger. Attach minimum 33.6 Amp 13.8 V supply, your SLA battery(ies),
and your load. (33.6 Amps is max load plus charging current.) The
controller will switch immediately to battery if the power supply DC goes
away. During heavy loads the power supply and battery will combine for
greater output. And of course the controller keeps battery charged. If
your batteries are flooded lead acid this is NOT the solution. Flooded lead
acid batteries require a three level charger.

I worked many years for firms that designed, manufactured, and installed
equipment requiring heavy battery backup. We NEVER attempted to isolate the
batteries from each other. We did always install new batteries of same
technology (FLA, AGM, Gel) and manufacture. In fact, my house emergency
power is a Trace inverter powered by 12 80AH AGM batteries in
series/parallel (48volt). They have been operating flawlessly for 8 years
now.

-----Original Message-----
From: Elecraft [mailto:[hidden email]] On Behalf Of N2TK,
Tony
Sent: Thursday, January 22, 2015 2:48 PM
To: [hidden email]
Subject: [Elecraft] Battery back-up system for multiple rigs

Looking for some advice. Trying to help out a friend who is setting up an
emergency communications system for the Hams in their condo group.

<snip>

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Jim Low man

Re: Battery back-up system for multiple rigs

Recently I purchased a DC-to-GO battery box, equipped with RIGrunner and
Super PWRgate PG40S, for home use.
It allows for 8 PowerPole connections and up to 40A continuous current.
I also bought the 79Ah battery that fits nicely inside the battery box.

For me, this serves a number of functions.
First, it serves as a UPS to protect my equipment.
Second, as emergency power for the shack.
We don't have power outages very often, but we recently had a couple of
protracted ones.
Further, it's a great portable power source for Field Day, etc.
The FD gang who I operate with are strictly QRP, so it would last forever.

I'm not sure that it would be a complete solution for your application,
but it's an idea.

73 de Jim - AD6CW
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Don Wilhelm-4

Re: Battery back-up system for multiple rigs

In reply to this post by N2TK

Tony,

There is no problem connecting batteries in parallel *if* (and only if)
they are the same capacity, manufacturer and age.

If the batteries are not identical, isolate them with diodes so one does
not draw current from another battery. You will suffer the diode
voltage drop in the output voltage. The diodes must be capable of
carrying the full maximum current load for all the rigs that will be
operating at the same time.

73,
Don W3FPR

On 1/22/2015 2:47 PM, N2TK, Tony wrote:

Elecraft mailing list

Re: Battery back-up system for multiple rigs

In reply to this post by N2TK

The first thing that comes to my mind is Line Loss
How far are they going to run the lines from the backup batteries to the radios?

From: "N2TK, Tony" <[hidden email]>
To: [hidden email]
Sent: Thursday, January 22, 2015 2:47 PM
Subject: [Elecraft] Battery back-up system for multiple rigs

Looking for some advice. Trying to help out a friend who is setting up an
emergency communications system for the Hams in their condo group.

They have several marine batteries they want to tie in parallel so they can
run multiple rigs, K3's plus UHF/VHF for extended periods. They have a
charger for the batteries. They use the 12V off the batteries to a
distribution box for the 12V equipment.

Questions:

- What is the best way to isolate the equipment from the batteries
if something happened to the battery (ies).

- Is there a way to isolate the batteries from each other if
something happened to one battery so it didn't draw down the other
batteries?

- Am I missing anything else that should be done for safety of the
equipment, batteries and the operators?

Tnx

N2TK, Tony

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k6dgw

Re: Battery back-up system for multiple rigs

In reply to this post by Don Wilhelm-4

and if they were *not* manufactured in China. Those vary so much, even
if they have identical model numbers, paralleling without diodes is a
recipe for failure. Been there, done that.

73,

Fred K6DGW
- Northern California Contest Club
- CU in the 50th Running of the Cal QSO Party 3-4 Oct 2015
- www.cqp.org

On 1/22/2015 4:20 PM, Don Wilhelm wrote:
> Tony,
>
> There is no problem connecting batteries in parallel *if* (and only if)
> they are the same capacity, manufacturer and age.

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Phil Kane-2

Re: Battery back-up system for multiple rigs

On 1/22/2015 4:45 PM, Fred Jensen wrote:

> and if they were *not* manufactured in China. Those vary so much, even
> if they have identical model numbers, paralleling without diodes is a
> recipe for failure. Been there, done that.

Which brands are / are not manufactured in China? I've been using
paralleled Trojan AGMs for many years with no problems. Interstate is
making big pitches here. I was always under the impression that there
were only 5 plants in the US making all the US brands. Info?

73 de K2ASP - Phil Kane
Elecraft K2/100 s/n 5402

From a Clearing in the Silicon Forest
Beaverton (Washington County) Oregon
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Fred Townsend-2

Re: Battery back-up system for multiple rigs

In reply to this post by Don Wilhelm-4

Don and Tony:
Diodes will get the job done but notice the heat sinks on them. They waste a
lot of energy as heat. I also read you have a single charger. I hear no
mention of fusing. Fusing is a good idea but must be done very carefully.
All of these issues are complicated by the placement of the diodes.

There are specifically designed 'smart' systems out there to do exactly the
job of safely sharing and charging batteries similar to the systems Jim,
AD6CW has suggested. If you lack experience in this area I highly recommend
to you check them out. They offer smart systems that will safely shut things
down using FETs to share and control. The FETs have much, much lower losses
so in this case the ones with diodes and big beefy heat sinks are not your
friend. The also feature both over voltage and under voltage alarms. This
saved me when a power supply regulator shorted.

73,
Fred, AE6QL

-----Original Message-----
From: Elecraft [mailto:[hidden email]] On Behalf Of Don
Wilhelm
Sent: Thursday, January 22, 2015 4:21 PM
To: N2TK, Tony; [hidden email]
Subject: Re: [Elecraft] Battery back-up system for multiple rigs

Tony,

There is no problem connecting batteries in parallel *if* (and only if) they
are the same capacity, manufacturer and age.

If the batteries are not identical, isolate them with diodes so one does not
draw current from another battery. You will suffer the diode voltage drop
in the output voltage. The diodes must be capable of carrying the full
maximum current load for all the rigs that will be operating at the same
time.

73,
Don W3FPR

On 1/22/2015 2:47 PM, N2TK, Tony wrote:
> Looking for some advice. Trying to help out a friend who is setting up an
> emergency communications system for the Hams in their condo group.
>
> They have several marine batteries they want to tie in parallel so they
can
> run multiple rigs, K3's plus UHF/VHF for extended periods. They have a
> charger for the batteries. They use the 12V off the batteries to a
> distribution box for the 12V equipment.
>
>
>
> Questions:
>
> - What is the best way to isolate the equipment from the
batteries
> if something happened to the battery (ies).
>
> - Is there a way to isolate the batteries from each other if
> something happened to one battery so it didn't draw down the other
> batteries?
>
> - Am I missing anything else that should be done for safety of
the

> equipment, batteries and the operators?
>
>
>
> Tnx
>
> N2TK, Tony
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]
>

Mike B-12

Re: Battery back-up system for multiple rigs

In reply to this post by Phil Kane-2

I spec'd Concorde AGM batteries for several years in NOAA climate stations.
Yes, they're more expensive than their Chinese copies, but more reliable. Plus,
I figured if I'm spending US tax dollars, I'm going to pay US workers.

http://www.concordebattery.com/

On 01/22/2015 08:49 PM, Phil Kane wrote:
> Which brands are / are not manufactured in China?

--
73,

Mike, KW1ND
Knoxville, TN
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N2TK

Re: Battery back-up system for multiple rigs

In reply to this post by Don Wilhelm-4

Tnx Don for the advice. The batteries are all identical marine type
batteries. But still like the idea of isolating them.
They will have solar and a generator too.
73,
N2TK, Tony

-----Original Message-----
From: Don Wilhelm [mailto:[hidden email]]
Sent: Thursday, January 22, 2015 7:21 PM
To: N2TK, Tony; [hidden email]
Subject: Re: [Elecraft] Battery back-up system for multiple rigs

Tony,

There is no problem connecting batteries in parallel *if* (and only if) they
are the same capacity, manufacturer and age.

If the batteries are not identical, isolate them with diodes so one does not
draw current from another battery. You will suffer the diode voltage drop
in the output voltage. The diodes must be capable of carrying the full
maximum current load for all the rigs that will be operating at the same
time.

73,
Don W3FPR

On 1/22/2015 2:47 PM, N2TK, Tony wrote:
> Looking for some advice. Trying to help out a friend who is setting up an
> emergency communications system for the Hams in their condo group.
>
> They have several marine batteries they want to tie in parallel so they
can
> run multiple rigs, K3's plus UHF/VHF for extended periods. They have a
> charger for the batteries. They use the 12V off the batteries to a
> distribution box for the 12V equipment.
>
>
>
> Questions:
>
> - What is the best way to isolate the equipment from the
batteries
> if something happened to the battery (ies).
>
> - Is there a way to isolate the batteries from each other if
> something happened to one battery so it didn't draw down the other
> batteries?
>
> - Am I missing anything else that should be done for safety of
the

N2TK

Re: Battery back-up system for multiple rigs

In reply to this post by Elecraft mailing list

Harry,

Good question. I will find out.

Thanks,

N2TK, Tony

From: Harry Yingst [mailto:[hidden email]]
Sent: Thursday, January 22, 2015 7:25 PM
To: N2TK, Tony; [hidden email]
Subject: Re: [Elecraft] Battery back-up system for multiple rigs

The first thing that comes to my mind is Line Loss

How far are they going to run the lines from the backup batteries to the
radios?

_____

From: "N2TK, Tony" <[hidden email]>
To: [hidden email]
Sent: Thursday, January 22, 2015 2:47 PM
Subject: [Elecraft] Battery back-up system for multiple rigs

Looking for some advice. Trying to help out a friend who is setting up an
emergency communications system for the Hams in their condo group.

They have several marine batteries they want to tie in parallel so they can
run multiple rigs, K3's plus UHF/VHF for extended periods. They have a
charger for the batteries. They use the 12V off the batteries to a
distribution box for the 12V equipment.

Questions:

- What is the best way to isolate the equipment from the batteries
if something happened to the battery (ies).

- Is there a way to isolate the batteries from each other if
something happened to one battery so it didn't draw down the other
batteries?

- Am I missing anything else that should be done for safety of the
equipment, batteries and the operators?

Tnx

N2TK, Tony

______________________________________________________________
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N2TK

Re: Battery back-up system for multiple rigs

In reply to this post by Fred Townsend-2

Fred,
Where can I find the info on the system AD6CW has suggested?
Tnx
N2TK, Tony

-----Original Message-----
From: Fred Townsend [mailto:[hidden email]]
Sent: Thursday, January 22, 2015 9:28 PM
To: [hidden email]; 'N2TK, Tony'; [hidden email]
Subject: RE: [Elecraft] Battery back-up system for multiple rigs

Don and Tony:
Diodes will get the job done but notice the heat sinks on them. They waste a
lot of energy as heat. I also read you have a single charger. I hear no
mention of fusing. Fusing is a good idea but must be done very carefully.
All of these issues are complicated by the placement of the diodes.

There are specifically designed 'smart' systems out there to do exactly the
job of safely sharing and charging batteries similar to the systems Jim,
AD6CW has suggested. If you lack experience in this area I highly recommend
to you check them out. They offer smart systems that will safely shut things
down using FETs to share and control. The FETs have much, much lower losses
so in this case the ones with diodes and big beefy heat sinks are not your
friend. The also feature both over voltage and under voltage alarms. This
saved me when a power supply regulator shorted.

73,
Fred, AE6QL

-----Original Message-----
From: Elecraft [mailto:[hidden email]] On Behalf Of Don
Wilhelm
Sent: Thursday, January 22, 2015 4:21 PM
To: N2TK, Tony; [hidden email]
Subject: Re: [Elecraft] Battery back-up system for multiple rigs

Tony,

There is no problem connecting batteries in parallel *if* (and only if) they
are the same capacity, manufacturer and age.

If the batteries are not identical, isolate them with diodes so one does not
draw current from another battery. You will suffer the diode voltage drop
in the output voltage. The diodes must be capable of carrying the full
maximum current load for all the rigs that will be operating at the same
time.

73,
Don W3FPR

On 1/22/2015 2:47 PM, N2TK, Tony wrote:
> Looking for some advice. Trying to help out a friend who is setting up
> an emergency communications system for the Hams in their condo group.
>
> They have several marine batteries they want to tie in parallel so
> they
can
> run multiple rigs, K3's plus UHF/VHF for extended periods. They have
> a charger for the batteries. They use the 12V off the batteries to a
> distribution box for the 12V equipment.
>
>
>
> Questions:
>
> - What is the best way to isolate the equipment from the
batteries
> if something happened to the battery (ies).
>
> - Is there a way to isolate the batteries from each other if
> something happened to one battery so it didn't draw down the other
> batteries?
>
> - Am I missing anything else that should be done for safety of
the

> equipment, batteries and the operators?
>
>
>
> Tnx
>
> N2TK, Tony
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net Please help support this email
> list: http://www.qsl.net/donate.html Message delivered to
> [hidden email]
>

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James Bennett

Re: Battery back-up system for multiple rigs

In reply to this post by Mike B-12

Just to put in my two centavos - I used three of the Concorde SunXtender 108ah batteriesin parallel in my shack running my K3 station and accessories (via a 72-watt solar panel) for almost nine years. Been told that's a pretty good life expectancy for them.

Jim Bennett / W6JHB
Folsom, CA

> On Jan 22, 2015, at 6:37 PM, Mike <[hidden email]> wrote:
>
> I spec'd Concorde AGM batteries for several years in NOAA climate stations. Yes, they're more expensive than their Chinese copies, but more reliable. Plus, I figured if I'm spending US tax dollars, I'm going to pay US workers.
>
> http://www.concordebattery.com/
>
>> On 01/22/2015 08:49 PM, Phil Kane wrote:
>> Which brands are / are not manufactured in China?
>
> --
> 73,
>
> Mike, KW1ND
> Knoxville, TN
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
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>
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