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Author Topic: AGM vs Gel Battery for FT-897D?  (Read 55419 times)
W8JX
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Posts: 12082




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« Reply #15 on: October 05, 2014, 01:25:10 PM »


I have had good luck with AGM batteries and even replaced the battery in my car with an Optima Yellow-Top that is about 2/3 the size but with 1/2 times more cranking amps than the conventional wet cell battery.


Optima batters are greatly over rated and over priced. Cranking power of any battery is a function of plate area to electrolyte. It is possible to pack a lot of cranking power in a wet cell too. The trade off is reserve capacity. You make a small battery with dense plate area you can have good surge power for size but the run out of gas quickly because they lack a volume of electrolyte for sustained power. Ideally for a deep cycle you want to focus less on large plate area and more on less plate area and more electrolyte for longer discharge capacity. Only with lithium can you truly get reduced weight and still have very high reserve capacity.
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Ham since 1969....  Old School 20wpm REAL Extra Class..
KD0SFY
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« Reply #16 on: October 05, 2014, 04:12:22 PM »

Let's look at say a BCI 35 series automotive battery as spec'd for one of my vehicles.

I can get a premium wet cell at 640 Cold Cranking Amps (800 Cranking Amps) and 100 Reserve Minutes.

I can get a basic wet cell at 490 CCA and 75 RM.

I can get the house brand AGM at 680 CCA (810 CA) and 100 RM.

I can get the Optima Deep Cycle (Yellow Top) at 620 CCA (775 CA) and 100 RM.

And I can get the Optima Starting battery (Red Top) at 720 CCA (910 CA) and 90 RM.


When it comes to radio use, you might as well toss out the CCA and CA numbers.  What you want to look for really will be the Amp hours (Ah) and the reserve. 
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W6EM
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« Reply #17 on: October 05, 2014, 06:20:06 PM »


I have had good luck with AGM batteries and even replaced the battery in my car with an Optima Yellow-Top that is about 2/3 the size but with 1/2 times more cranking amps than the conventional wet cell battery.


....... Only with lithium can you truly get reduced weight and still have very high reserve capacity.
And, from what I've read since this started, irreparable damage/failure if discharged well over 80%.  No thanks, at least at 4X the equivalent $ per AH.  At least for now, I'll carry the load.....of lead.  At least if SLA or flooded LA are run all the way down, you can recharge them.  Sure, life may be lessened, but not gone after one deep discharge.

Like we used to say about VRLA UPS batteries, not maintenance-free, but maintenance-proof.  For LiFEPO4, looks like they're maintenance-POOF!
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G4AON
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« Reply #18 on: October 06, 2014, 04:50:15 AM »

I'm thinking a battery box and battery for my Yaesu FT-897D, for home use as a backup and for portable use. I read that gel batteries are on the out and AGM the preferred primary option. But I don't know...

I'm looking for an off-the-shelf solution and considering the WMR setup as follows:

1. DC-to-GO Battery Box w/RIGrunner & Super PWRgate http://www.westmountainradio.com/product_info.php?products_id=dc_special

2. Battery
a. Sealed Lead Acid 79 Amp Hour AGM Battery (20 Hr Rate) http://www.westmountainradio.com/product_info.php?products_id=M24SLDA
or
b. Gel 73 Amp Hour Deep-Cycle Battery (20 Hr Rate) http://www.westmountainradio.com/product_info.php?products_id=gel73

3. Powerwerx 30 Amp Desktop Switching Power Supply with Powerpoles http://www.westmountainradio.com/product_info.php?products_id=ss-30dv

I'm sure there are cheaper options, but does this look to do the job?

What reasons to choose Gel vs AGM battery?
I am not convinced that your desktop power supply/charger will give the best results from an AGM or Gel Cell battery. The modern trend is for a multi-step charger, which in my experience is worth considering over a fixed Voltage one.

For several years I've operated /P from the local hills with a 100 Watt radio. I've gone through a few cheap and hopeless "leisure" type batteries over the years and now use a professional grade AGM. I've a page on the subject at: http://www.qsl.net/g4aon/batteries/

Your needs may not be quite the same, but it might help you decide.

73 Dave
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W8JX
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« Reply #19 on: October 06, 2014, 06:56:38 AM »

Let's look at say a BCI 35 series automotive battery as spec'd for one of my vehicles.

I can get a premium wet cell at 640 Cold Cranking Amps (800 Cranking Amps) and 100 Reserve Minutes.

I can get a basic wet cell at 490 CCA and 75 RM.

I can get the house brand AGM at 680 CCA (810 CA) and 100 RM.

I can get the Optima Deep Cycle (Yellow Top) at 620 CCA (775 CA) and 100 RM.

And I can get the Optima Starting battery (Red Top) at 720 CCA (910 CA) and 90 RM.


When it comes to radio use, you might as well toss out the CCA and CA numbers.  What you want to look for really will be the Amp hours (Ah) and the reserve.  


I have two wet cells in my gas 1 ton plow truck. I have 925 CCA (CA 1100) and 145 RM each battery. Optima batteries would not last long here and provide reduced performance. Batteries are my life blood here and I do not mess around. I once lost a alternator while plowing at 5am one winter morning. I was able to run about 20 min to finish job and make a slow 13 mile trip home in dark in bad weather with lights wipers and heater/defroster. I figure I was averaging 65 amps or more draw (plus amp 150 amp for plow motor when it was used) and still had some reserve when I got home nearly a hour later. Would of never made it with even two optimas. I remember 4 years ago plowing in a big storm for several hours I had actually used up reserve in both batteries with heavy use of plow motor. As I finished I noticed plow getting sluggish. Again would of been SOL with Optimas. My alt puts out 135 amp and batteries helps carry surge loads. Since then I converted to LED running lights on truck and plow and and used LED backup liight bulb replacements too. This reduce lighting load with headlight and running lights from 35 amps to twenty and brake lights (which are used a lot) from 10 amps to 2 amps. and back light load from 5 amps to about 1. Since these mods I have had no more battery issues even in extreme duty. I switched over to a Class 1 LED beacon too that uses less than 2 amps vs 10 with bulbs.

Sometimes the answer is simply to get more efficient.  

BTW, reserve capacity is number of minutes with a 25 amp load. As you increase load the results are not linear especially in small AGM battery. At 50 amps you might get 30 minutes and at 75 amps 20 if your lucky. A big wet cell will do better here.
« Last Edit: October 06, 2014, 07:21:39 AM by W8JX » Logged

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Ham since 1969....  Old School 20wpm REAL Extra Class..
W1JKA
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Posts: 2087




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« Reply #20 on: October 06, 2014, 07:44:27 AM »

Re: Reply #19

   Amazing, finally a post from W8JX I can relate to and agree with 100%. For all my QRP portable ops either solo or with one or two others I carry a 5 lb. auto jump start battery with small solar panel to power 1 or two small qrp rigs indefinitely under normal usage. Five pounds added weight to my 25 pound loaded ALICE pack is no burden for 1-4 mile hikes into or between campsites or swapping the carry between two people every half hour on a moderate SOTA climb even for us 66+ year olds.
   No doubt that you even have one in your plow truck. Common sense and practicality more often than not outweighs expensive Hi-tech.
« Last Edit: October 06, 2014, 07:48:27 AM by W1JKA » Logged
W8JX
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Posts: 12082




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« Reply #21 on: October 06, 2014, 08:35:00 AM »

Re: Reply #19

   Amazing, finally a post from W8JX I can relate to and agree with 100%. For all my QRP portable ops either solo or with one or two others I carry a 5 lb. auto jump start battery with small solar panel to power 1 or two small qrp rigs indefinitely under normal usage. Five pounds added weight to my 25 pound loaded ALICE pack is no burden for 1-4 mile hikes into or between campsites or swapping the carry between two people every half hour on a moderate SOTA climb even for us 66+ year olds.
   No doubt that you even have one in your plow truck. Common sense and practicality more often than not outweighs expensive Hi-tech.


I carry a small 2 stroke generator with some drop lights, charger, a 600 watt heater and extension cord in tool box. I normally carry 2 stroke premix fuel for snow blowers.
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Ham since 1969....  Old School 20wpm REAL Extra Class..
KD0SFY
Member

Posts: 451




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« Reply #22 on: October 06, 2014, 04:36:32 PM »



I have two wet cells in my gas 1 ton plow truck. I have 925 CCA (CA 1100) and 145 RM each battery. Optima batteries would not last long here and provide reduced performance.

The Optima D31 would probably work fine.  It is a deep cycle AGM, 900/1125 with 155 RM.  Some vehicle charging systems do have to be modified to correctly charge AGMs.

Regardless of how they work in a vehicle, AGMs work quite well for radio.  The biggest problem with AGMs is some people do not use a good charger/conditioner/maintainer with them.
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KD0SFY
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« Reply #23 on: October 06, 2014, 04:40:19 PM »

For all my QRP portable ops either solo or with one or two others I carry a 5 lb. auto jump start battery


Many of which are AGMs.
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W8JX
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Posts: 12082




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« Reply #24 on: October 06, 2014, 05:06:07 PM »

For all my QRP portable ops either solo or with one or two others I carry a 5 lb. auto jump start battery


Many of which are AGMs.

Never see a electric car powered by AGM and must be for a reason too. They used lead acid or NiMH or Lithium. AGM is good for standby power with with limited discharge usage.
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Ham since 1969....  Old School 20wpm REAL Extra Class..
W9FIB
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Posts: 2103




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« Reply #25 on: October 06, 2014, 05:34:50 PM »

For all my QRP portable ops either solo or with one or two others I carry a 5 lb. auto jump start battery


Many of which are AGMs.

Never see a electric car powered by AGM and must be for a reason too. They used lead acid or NiMH or Lithium. AGM is good for standby power with with limited discharge usage.

Never seen a jump start battery used to run an electric car. I have seen them help start internal combustion engines though. I think your confused.
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Happy being an Amateur Extra!
Nothing says CB on my printed license.
Ares/Races but no lights or crown vic.
K5LXP
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Posts: 5333


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« Reply #26 on: October 06, 2014, 07:44:26 PM »

Never see a electric car powered by AGM

The Ford Ranger EV was offered with AGM's, and with NiMH as an option.  I recall the first generation GM EV1 also shipped with AGM's, and Gen 2 offered NiMH.  Not saying AGM's are the best EV battery but back then, they were about the only choice.  AGM's offer lower internal impedance compared to flooded PbA and are a good choice even in tepid ham radio applications if cost isn't a primary factor, as they are more expensive per Ah than flooded PbA.  They also require more careful charging.

Mark K5LXP
Albuquerque, NM

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W8JX
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Posts: 12082




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« Reply #27 on: October 07, 2014, 03:32:46 AM »

Never see a electric car powered by AGM

The Ford Ranger EV was offered with AGM's, and with NiMH as an option.  I recall the first generation GM EV1 also shipped with AGM's, and Gen 2 offered NiMH.  Not saying AGM's are the best EV battery but back then, they were about the only choice.  AGM's offer lower internal impedance compared to flooded PbA and are a good choice even in tepid ham radio applications if cost isn't a primary factor, as they are more expensive per Ah than flooded PbA.  They also require more careful charging.

Mark K5LXP
Albuquerque, NM



EV1 had lead acid. I also saw a S10 prototype in person that was electric and had about 1000 lbs lead acid cell in bed. They were using it for electric motor development.

A chevy Volt will not start and run if its 12v battery is dead. While it is not used to start range extender gas engine, it is used to turn on electronics that drive car. Once running the system can charge 12v battery.
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Ham since 1969....  Old School 20wpm REAL Extra Class..
W9FIB
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Posts: 2103




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« Reply #28 on: October 07, 2014, 09:06:38 AM »

Never see a electric car powered by AGM

The Ford Ranger EV was offered with AGM's, and with NiMH as an option.  I recall the first generation GM EV1 also shipped with AGM's, and Gen 2 offered NiMH.  Not saying AGM's are the best EV battery but back then, they were about the only choice.  AGM's offer lower internal impedance compared to flooded PbA and are a good choice even in tepid ham radio applications if cost isn't a primary factor, as they are more expensive per Ah than flooded PbA.  They also require more careful charging.

Mark K5LXP
Albuquerque, NM



Thanks for attributing the WRONG quote to me! If your going to edit a quote...please make sure the right quote is with the right person!
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Happy being an Amateur Extra!
Nothing says CB on my printed license.
Ares/Races but no lights or crown vic.
K5LXP
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Posts: 5333


WWW

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« Reply #29 on: October 07, 2014, 12:43:27 PM »

Thanks for attributing the WRONG quote to me!

Sorry.  When you hit the quote button on that post you end up with a list at the top and disconnected statements below.


Mark K5LXP
Albuquerque, NM
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