Topics

Trojan AGMs


Jerry Knowles
 

 

Has anyone had any experience with the 6v GC AGM batteries from Trojan or Fall River?  I understand that you can draw them down 80% vs only 50% with lead acid batteries.  I’m using the Costco Interstate GC batteries and am thinking of upgrading to extend my boondocking capability.
Jerry K
2018 J


Richard Filcoff
 

Per Battery University, AGM’s can occasionally be drawn own to 20% S.O.C. without adverse effect if the batteries are promptly retuned to a full state of charge.  It is my understanding from this source and other sources that the degradation to the capacity of  AGM batteries occurs if these batteries are allowed to remain at a low S.O.C. for an extended period.  Carbon foam batteries, on the other hand, can repeatedly be discharged to 20% S.O.C. without degradation of capacity, perform well in cold temperatures and use the same charging equipment as do AGM batteries.  A group 31 carbon foam battery costs approx 1.5X to 2X the cost of a similar capacity group 31 AGM battery.

Rick Filcoff

From: discussion@view-naviontech.groups.io <discussion@view-naviontech.groups.io> On Behalf Of Jerry Knowles
Sent: Wednesday, October 14, 2020 10:34 AM
To: discussion@view-naviontech.groups.io
Subject: [view-naviontech] Trojan AGMs

 

 

Has anyone had any experience with the 6v GC AGM batteries from Trojan or Fall River?  I understand that you can draw them down 80% vs only 50% with lead acid batteries.  I’m using the Costco Interstate GC batteries and am thinking of upgrading to extend my boondocking capability.
Jerry K
2018 J


Dick Stevenson
 

Hi Jerry,
No experience with Trojan, but in the long-distance live-aboard sailing world where one is living off DC for long periods, Lifeline AGMs seem to be the batteries most discerning cruisers choose. They are, I believe, the only AGMs that allow for equalization which will extend a battery’s life. That, I believe, is possible because of the quality and robustness of the build.

And AGMs are lead acid/electrolyte batteries. I suspect you are referring to wet cell batteries, either maintenance free or the ones where you can add water or electrolyte.

AGMs (and gels) are likely to tolerate an 80% discharge better than most wet cells but neither will like that degree of depletion: the deeper depletion (>50%) the shorter the life span and the fewer charge cycles. Your Interstate batteries may only tolerate a few depletions to 80% before ready for the graveyard.

Decent prices on AGM Lifeline batteries can be (or used to be) found at West Marine or Defender Ind. Although now that battery stores seem to abound, they may be the most competitive.

One caveat for AGMs when boondocking for longer periods: they like to be fully charged every couple of weeks, sometimes not so easy to come by off the grid and charging from 50% depleted to 80%. That last 20% is hard to come by unless there is good solar and sun.

My best, Dick Stevenson


David J
 

Agree, you can discharge AGMs to 80% only three or four times before losing significant capacity, and then only if you recharge within a few hours. There really isn't any difference between these and flooded lead acid types, in my experience. I have used the AGM batteries from Trojan and found them fine but no improvement over their flooded GCs (GC2, T105, T125.) Most battery manufacturers publish a cycle life chart, defining end-of-life as 60% of capacity. Generally "80% depth of discharge" is defined as specific gravity around 1.098, about 1.93 volts per cell or 11.58 volts at the battery. Is that really what you mean by 80% DOD? It only takes one cell going below that to sustain significant damage to the battery. 

I'm looking forward to more reports on carbon foam batteries, but at the moment there is only one manufacturer and it's only 20-30% lower cost than an equivalent LiFePO4 battery. 


Richard Filcoff
 

The prices for carbon foam batteries are considerable less than 20-30% lower than drop-in equivalent LitfePO4 batteries.

Carbon foam 116 A-H 543 + $8 = $551

https://docs.google.com/document/d/1t2ohxhDQnATqbTi4DlQUj6gsOwFaulhYZQltHp4GKrY/edit

Battle Born 00 A-H $949

https://battlebornbatteries.com/product-category/lifepo4-batteries/

Also, the carbon foam batteries withstand much colder temperatures than do LiFePO4,borht for charging/discharging and for storage.  In fac , in  approx.-half of the U.S. states, you would not be able to subject he batteries while your RV is in storage to the coldest likely winter  temperatures.  We are on a hill approx. 25 miles west of St. Louis. Some people consider us to be “midwestern,”  some consider us to be a “southern” state, others a “mid-south” state.  Whichever is the case, it down to -20F or lower here during the winter.

Rick Filcoff

W0RCF

 

 

 

 

 

 

From: discussion@view-naviontech.groups.io <discussion@view-naviontech.groups.io> On Behalf Of David J
Sent: Wednesday, October 14, 2020 12:39 PM
To: discussion@view-naviontech.groups.io
Subject: Re: [view-naviontech] Trojan AGMs

 

Agree, you can discharge AGMs to 80% only three or four times before losing significant capacity, and then only if you recharge within a few hours. There really isn't any difference between these and flooded lead acid types, in my experience. I have used the AGM batteries from Trojan and found them fine but no improvement over their flooded GCs (GC2, T105, T125.) Most battery manufacturers publish a cycle life chart, defining end-of-life as 60% of capacity. Generally "80% depth of discharge" is defined as specific gravity around 1.098, about 1.93 volts per cell or 11.58 volts at the battery. Is that really what you mean by 80% DOD? It only takes one cell going below that to sustain significant damage to the battery. 

I'm looking forward to more reports on carbon foam batteries, but at the moment there is only one manufacturer and it's only 20-30% lower cost than an equivalent LiFePO4 battery. 


David J
 

Rick, I was comparing cost with shipping - Battle Born price includes shipping.  Lowest cost I find for Firefly shipped to California is about $673. And this is compared with GC2 batteries (same energy, double the amp-hours, half the voltage) for $150 with core charge, at a local store.

As you say, LiFePO4 batteries can't be charged below freezing (or discharged much below freezing) but they don't care if they are frozen while charged. There is no perfect solution. 

It's a little disingenuous for Firefly to claim that it's fundamentally different from a lead-acid battery. The active surface is still lead, and the electrolyte is still sulfuric acid. It's very early days for this technology, there is only one small manufacturer. See their patent 6979513. Carbon foam is really intriguing as a substrate for the lead, but it is still an electrolyte battery and there will still be corrosion potential in the attachments to the carbon foam electrodes. 

73 de David WA6NMF


David J
 

There's an interesting writeup on the inventor of this battery and its history at https://books.google.com/books?id=gliiDAAAQBAJ&pg=PA120&lpg=PA120&dq=kurtis+chad+kelley&source=bl&ots=M-O3lp-9FS&sig=ACfU3U2XcyIeqy1KCg0ETew4KuTsAynZqg&hl=en&sa=X&ved=2ahUKEwispcy96bTsAhXkJTQIHTe2AR8Q6AEwDnoECAcQAg#v=onepage&q=kurtis%20chad%20kelley&f=false


Richard Filcoff
 

Wow, that is some shipping charge!  The Firefly website indicates that they are located in Maine. I wonder if this can be combined with trip to Acadia NP 😊

 

Battle Born Technical Support told me I would have to remove the batteries during the winter for inside storage to avoid damage due to the low temperatures here (-20F or lower).  They did say that Battle Born Batteries with built in heaters would soon be announced and that as long as I am plugged into shore power and the heaters are provided with power re, I would not have to bring them into a heated area for storage.  Not sure that I would want to take that change on $2,000 worth of batteries.

Rick

From: discussion@view-naviontech.groups.io <discussion@view-naviontech.groups.io> On Behalf Of David J
Sent: Wednesday, October 14, 2020 2:18 PM
To: discussion@view-naviontech.groups.io
Subject: Re: [view-naviontech] Trojan AGMs

 

Rick, I was comparing cost with shipping - Battle Born price includes shipping.  Lowest cost I find for Firefly shipped to California is about $673. And this is compared with GC2 batteries (same energy, double the amp-hours, half the voltage) for $150 with core charge, at a local store.

As you say, LiFePO4 batteries can't be charged below freezing (or discharged much below freezing) but they don't care if they are frozen while charged. There is no perfect solution. 

It's a little disingenuous for Firefly to claim that it's fundamentally different from a lead-acid battery. The active surface is still lead, and the electrolyte is still sulfuric acid. It's very early days for this technology, there is only one small manufacturer. See their patent 6979513. Carbon foam is really intriguing as a substrate for the lead, but it is still an electrolyte battery and there will still be corrosion potential in the attachments to the carbon foam electrodes. 

73 de David WA6NMF


David J
 

Firefly went bankrupt in 2010. Oceanplanetenergy is in Maine, but is just a dealer. The new owners (who bought the assets out of the bankruptcy auction) are in Peoria, IL. The current company website is fireflyenergy.com and it would appear that manufacturing is offshore.

https://www.youtube.com/watch?v=LvEkUXOJo-w is a minute of a fellow from Battle Born explaining how to charge and leave their batteries over a winter. The key is to be sure they are stored charged and don't try to flow any current into or out of the battery when it's frozen.

In the electric aviation community we've seen hundreds of amazing new battery ideas, it's usually pretty simple to see why they aren't quite ready for prime time. For a while I worked with the former head of battery tech for a major electric car company, and she was even more skeptical of many of new ideas than I am. You can watch her thumbnail talk about some of the issues at https://www.youtube.com/watch?v=J1LnEXelANQ


Frank Hughes
 

We have had a pair of TROJAN T-105 AGM in our 2017 24G for a couple of years.
Made the Summer of 2019 in Alaska very comfortable.
I don’t recall ever seeing a discharge level below 85% in use so far.
Run the CPAP all night, but it is converted to DC, thus no inverter needed.
Charging while camped is from a Panasonic VBHN330SA17 330 watt panel.


Jerry Knowles
 

Thanks everyone for your great advice.  Talked to Lifeline today and they said that it is best not to discharge below 50%.  Said at that rate could get about 1200 cycles, but at 80% could get maybe 300 cycles.  I have 200w of solar and a generator so doubt that I would need to draw down below 50%, since I probably won’t boondock for more than a few days in any 1 place or if longer it would be in full sun such as AZ or Utah.

Interesting on the Interstates.  I’m on my 3rd set in less than 3 years the last set being replaced under warranty from Costco.  I have an unexplained draw.  With all of my fuses out and the propane off I still draw .8 amp as measured by my battery monitor.  I’ve been working with fellow group member Dee Riby to try and figure this out And we are at a loss.  Also enlisted my son who works with electronics and he is at a loss.  Talked to a tech at Winnebago who says that the .8 with all fuses out is normal, that if they have a coach on the lot with the battery switch on they will discharge completely over the weekend.  With all fuses in and propane on and nothing else I draw 1.3 amps.  It seems that I need to live with this, hence my seeking to upgrade my batteries.
Thanks again for all of your help on this.
Jerry K
2018J



On Oct 14, 2020, at 9:20 AM, Dick Stevenson <alchemy128@...> wrote:



Hi Jerry,
No experience with Trojan, but in the long-distance live-aboard sailing world where one is living off DC for long periods, Lifeline AGMs seem to be the batteries most discerning cruisers choose. They are, I believe, the only AGMs that allow for equalization which will extend a battery’s life. That, I believe, is possible because of the quality and robustness of the build.

And AGMs are lead acid/electrolyte batteries. I suspect you are referring to wet cell batteries, either maintenance free or the ones where you can add water or electrolyte.

AGMs (and gels) are likely to tolerate an 80% discharge better than most wet cells but neither will like that degree of depletion: the deeper depletion (>50%) the shorter the life span and the fewer charge cycles. Your Interstate batteries may only tolerate a few depletions to 80% before ready for the graveyard.

Decent prices on AGM Lifeline batteries can be (or used to be) found at West Marine or Defender Ind. Although now that battery stores seem to abound, they may be the most competitive.

One caveat for AGMs when boondocking for longer periods: they like to be fully charged every couple of weeks, sometimes not so easy to come by off the grid and charging from 50% depleted to 80%. That last 20% is hard to come by unless there is good solar and sun.

My best, Dick Stevenson


Bob
 

My 18G has 2 HDMI splitters between the side wall where the main TV is mounted. They are always drawing power. Also any coach USB ports. Whenever the coach main power switch is on. 

Bob.


On Oct 15, 2020, at 13:20, Jerry Knowles <knowlesjv087@...> wrote:


Thanks everyone for your great advice.  Talked to Lifeline today and they said that it is best not to discharge below 50%.  Said at that rate could get about 1200 cycles, but at 80% could get maybe 300 cycles.  I have 200w of solar and a generator so doubt that I would need to draw down below 50%, since I probably won’t boondock for more than a few days in any 1 place or if longer it would be in full sun such as AZ or Utah.

Interesting on the Interstates.  I’m on my 3rd set in less than 3 years the last set being replaced under warranty from Costco.  I have an unexplained draw.  With all of my fuses out and the propane off I still draw .8 amp as measured by my battery monitor.  I’ve been working with fellow group member Dee Riby to try and figure this out And we are at a loss.  Also enlisted my son who works with electronics and he is at a loss.  Talked to a tech at Winnebago who says that the .8 with all fuses out is normal, that if they have a coach on the lot with the battery switch on they will discharge completely over the weekend.  With all fuses in and propane on and nothing else I draw 1.3 amps.  It seems that I need to live with this, hence my seeking to upgrade my batteries.
Thanks again for all of your help on this.
Jerry K
2018J



On Oct 14, 2020, at 9:20 AM, Dick Stevenson <alchemy128@...> wrote:



Hi Jerry,
No experience with Trojan, but in the long-distance live-aboard sailing world where one is living off DC for long periods, Lifeline AGMs seem to be the batteries most discerning cruisers choose. They are, I believe, the only AGMs that allow for equalization which will extend a battery’s life. That, I believe, is possible because of the quality and robustness of the build.

And AGMs are lead acid/electrolyte batteries. I suspect you are referring to wet cell batteries, either maintenance free or the ones where you can add water or electrolyte.

AGMs (and gels) are likely to tolerate an 80% discharge better than most wet cells but neither will like that degree of depletion: the deeper depletion (>50%) the shorter the life span and the fewer charge cycles. Your Interstate batteries may only tolerate a few depletions to 80% before ready for the graveyard.

Decent prices on AGM Lifeline batteries can be (or used to be) found at West Marine or Defender Ind. Although now that battery stores seem to abound, they may be the most competitive.

One caveat for AGMs when boondocking for longer periods: they like to be fully charged every couple of weeks, sometimes not so easy to come by off the grid and charging from 50% depleted to 80%. That last 20% is hard to come by unless there is good solar and sun.

My best, Dick Stevenson


Jerry Knowles
 

All HDMIs are unplugged.  USBs shouldn’t draw unless a device is hooked up to them.


On Oct 15, 2020, at 2:03 PM, Bob via groups.io <nw8r@...> wrote:

My 18G has 2 HDMI splitters between the side wall where the main TV is mounted. They are always drawing power. Also any coach USB ports. Whenever the coach main power switch is on. 

Bob.


On Oct 15, 2020, at 13:20, Jerry Knowles <knowlesjv087@...> wrote:


Thanks everyone for your great advice.  Talked to Lifeline today and they said that it is best not to discharge below 50%.  Said at that rate could get about 1200 cycles, but at 80% could get maybe 300 cycles.  I have 200w of solar and a generator so doubt that I would need to draw down below 50%, since I probably won’t boondock for more than a few days in any 1 place or if longer it would be in full sun such as AZ or Utah.

Interesting on the Interstates.  I’m on my 3rd set in less than 3 years the last set being replaced under warranty from Costco.  I have an unexplained draw.  With all of my fuses out and the propane off I still draw .8 amp as measured by my battery monitor.  I’ve been working with fellow group member Dee Riby to try and figure this out And we are at a loss.  Also enlisted my son who works with electronics and he is at a loss.  Talked to a tech at Winnebago who says that the .8 with all fuses out is normal, that if they have a coach on the lot with the battery switch on they will discharge completely over the weekend.  With all fuses in and propane on and nothing else I draw 1.3 amps.  It seems that I need to live with this, hence my seeking to upgrade my batteries.
Thanks again for all of your help on this.
Jerry K
2018J



On Oct 14, 2020, at 9:20 AM, Dick Stevenson <alchemy128@...> wrote:



Hi Jerry,
No experience with Trojan, but in the long-distance live-aboard sailing world where one is living off DC for long periods, Lifeline AGMs seem to be the batteries most discerning cruisers choose. They are, I believe, the only AGMs that allow for equalization which will extend a battery’s life. That, I believe, is possible because of the quality and robustness of the build.

And AGMs are lead acid/electrolyte batteries. I suspect you are referring to wet cell batteries, either maintenance free or the ones where you can add water or electrolyte.

AGMs (and gels) are likely to tolerate an 80% discharge better than most wet cells but neither will like that degree of depletion: the deeper depletion (>50%) the shorter the life span and the fewer charge cycles. Your Interstate batteries may only tolerate a few depletions to 80% before ready for the graveyard.

Decent prices on AGM Lifeline batteries can be (or used to be) found at West Marine or Defender Ind. Although now that battery stores seem to abound, they may be the most competitive.

One caveat for AGMs when boondocking for longer periods: they like to be fully charged every couple of weeks, sometimes not so easy to come by off the grid and charging from 50% depleted to 80%. That last 20% is hard to come by unless there is good solar and sun.

My best, Dick Stevenson


Glenn Franco
 

Sorry if I rain on the AGM parade but I have had at least 5 occasions where my new AGM batteries have been discharged below 50% and the batteries had to be replaced and would not take a charge under any circumstances.
Under NO circumstances would I replace any wet cell batteries at this point with AGMs.
If you do Good Luck as I'm over the AGM thing. Maybe Lithium is the way to go.
Glenn 06 23H 38k mi with 5 DEAD AGM's that were less than 3 months old!!!


On Thu, Oct 15, 2020 at 6:50 PM Jerry Knowles <knowlesjv087@...> wrote:
All HDMIs are unplugged.  USBs shouldn’t draw unless a device is hooked up to them.


On Oct 15, 2020, at 2:03 PM, Bob via groups.io <nw8r=yahoo.com@groups.io> wrote:

My 18G has 2 HDMI splitters between the side wall where the main TV is mounted. They are always drawing power. Also any coach USB ports. Whenever the coach main power switch is on. 

Bob.


On Oct 15, 2020, at 13:20, Jerry Knowles <knowlesjv087@...> wrote:


Thanks everyone for your great advice.  Talked to Lifeline today and they said that it is best not to discharge below 50%.  Said at that rate could get about 1200 cycles, but at 80% could get maybe 300 cycles.  I have 200w of solar and a generator so doubt that I would need to draw down below 50%, since I probably won’t boondock for more than a few days in any 1 place or if longer it would be in full sun such as AZ or Utah.

Interesting on the Interstates.  I’m on my 3rd set in less than 3 years the last set being replaced under warranty from Costco.  I have an unexplained draw.  With all of my fuses out and the propane off I still draw .8 amp as measured by my battery monitor.  I’ve been working with fellow group member Dee Riby to try and figure this out And we are at a loss.  Also enlisted my son who works with electronics and he is at a loss.  Talked to a tech at Winnebago who says that the .8 with all fuses out is normal, that if they have a coach on the lot with the battery switch on they will discharge completely over the weekend.  With all fuses in and propane on and nothing else I draw 1.3 amps.  It seems that I need to live with this, hence my seeking to upgrade my batteries.
Thanks again for all of your help on this.
Jerry K
2018J



On Oct 14, 2020, at 9:20 AM, Dick Stevenson <alchemy128@...> wrote:



Hi Jerry,
No experience with Trojan, but in the long-distance live-aboard sailing world where one is living off DC for long periods, Lifeline AGMs seem to be the batteries most discerning cruisers choose. They are, I believe, the only AGMs that allow for equalization which will extend a battery’s life. That, I believe, is possible because of the quality and robustness of the build.

And AGMs are lead acid/electrolyte batteries. I suspect you are referring to wet cell batteries, either maintenance free or the ones where you can add water or electrolyte.

AGMs (and gels) are likely to tolerate an 80% discharge better than most wet cells but neither will like that degree of depletion: the deeper depletion (>50%) the shorter the life span and the fewer charge cycles. Your Interstate batteries may only tolerate a few depletions to 80% before ready for the graveyard.

Decent prices on AGM Lifeline batteries can be (or used to be) found at West Marine or Defender Ind. Although now that battery stores seem to abound, they may be the most competitive.

One caveat for AGMs when boondocking for longer periods: they like to be fully charged every couple of weeks, sometimes not so easy to come by off the grid and charging from 50% depleted to 80%. That last 20% is hard to come by unless there is good solar and sun.

My best, Dick Stevenson


Jerry Knowles
 

What was the brand of the AGMs.  Were they under warranty?
Jerry K
18 J

On Oct 15, 2020, at 4:17 PM, Glenn Franco <brakey6666@...> wrote:


Sorry if I rain on the AGM parade but I have had at least 5 occasions where my new AGM batteries have been discharged below 50% and the batteries had to be replaced and would not take a charge under any circumstances.
Under NO circumstances would I replace any wet cell batteries at this point with AGMs.
If you do Good Luck as I'm over the AGM thing. Maybe Lithium is the way to go.
Glenn 06 23H 38k mi with 5 DEAD AGM's that were less than 3 months old!!!


On Thu, Oct 15, 2020 at 6:50 PM Jerry Knowles <knowlesjv087@...> wrote:
All HDMIs are unplugged.  USBs shouldn’t draw unless a device is hooked up to them.


On Oct 15, 2020, at 2:03 PM, Bob via groups.io <nw8r=yahoo.com@groups.io> wrote:

My 18G has 2 HDMI splitters between the side wall where the main TV is mounted. They are always drawing power. Also any coach USB ports. Whenever the coach main power switch is on. 

Bob.


On Oct 15, 2020, at 13:20, Jerry Knowles <knowlesjv087@...> wrote:


Thanks everyone for your great advice.  Talked to Lifeline today and they said that it is best not to discharge below 50%.  Said at that rate could get about 1200 cycles, but at 80% could get maybe 300 cycles.  I have 200w of solar and a generator so doubt that I would need to draw down below 50%, since I probably won’t boondock for more than a few days in any 1 place or if longer it would be in full sun such as AZ or Utah.

Interesting on the Interstates.  I’m on my 3rd set in less than 3 years the last set being replaced under warranty from Costco.  I have an unexplained draw.  With all of my fuses out and the propane off I still draw .8 amp as measured by my battery monitor.  I’ve been working with fellow group member Dee Riby to try and figure this out And we are at a loss.  Also enlisted my son who works with electronics and he is at a loss.  Talked to a tech at Winnebago who says that the .8 with all fuses out is normal, that if they have a coach on the lot with the battery switch on they will discharge completely over the weekend.  With all fuses in and propane on and nothing else I draw 1.3 amps.  It seems that I need to live with this, hence my seeking to upgrade my batteries.
Thanks again for all of your help on this.
Jerry K
2018J



On Oct 14, 2020, at 9:20 AM, Dick Stevenson <alchemy128@...> wrote:



Hi Jerry,
No experience with Trojan, but in the long-distance live-aboard sailing world where one is living off DC for long periods, Lifeline AGMs seem to be the batteries most discerning cruisers choose. They are, I believe, the only AGMs that allow for equalization which will extend a battery’s life. That, I believe, is possible because of the quality and robustness of the build.

And AGMs are lead acid/electrolyte batteries. I suspect you are referring to wet cell batteries, either maintenance free or the ones where you can add water or electrolyte.

AGMs (and gels) are likely to tolerate an 80% discharge better than most wet cells but neither will like that degree of depletion: the deeper depletion (>50%) the shorter the life span and the fewer charge cycles. Your Interstate batteries may only tolerate a few depletions to 80% before ready for the graveyard.

Decent prices on AGM Lifeline batteries can be (or used to be) found at West Marine or Defender Ind. Although now that battery stores seem to abound, they may be the most competitive.

One caveat for AGMs when boondocking for longer periods: they like to be fully charged every couple of weeks, sometimes not so easy to come by off the grid and charging from 50% depleted to 80%. That last 20% is hard to come by unless there is good solar and sun.

My best, Dick Stevenson


David J
 

1. USB adapters often draw a significant amount of power from 12V even if there is no USB device plugged in. You can measure this.

2. Agreed with the assessment of AGM vs flooded. Several recent experiences with top-notch (Optima) AGM were not positive. I would use AGM or VRLA only when I couldn't deal with acid vapor or regular maintenance.


Dick Stevenson
 

Hi Glenn,
Who made the AGMs that failed on you? 
Thanks, Dick Stevenson


Bob
 

Each of the usb chargers in my 18 coach draw 22mA standby. Nothing plugged into them.
Not much, but it all adds up.

Bob 18G


On Oct 15, 2020, at 6:50 PM, Jerry Knowles <knowlesjv087@...> wrote:

All HDMIs are unplugged.  USBs shouldn’t draw unless a device is hooked up to them.


On Oct 15, 2020, at 2:03 PM, Bob via groups.io <nw8r@...> wrote:

My 18G has 2 HDMI splitters between the side wall where the main TV is mounted. They are always drawing power. Also any coach USB ports. Whenever the coach main power switch is on. 

Bob.


On Oct 15, 2020, at 13:20, Jerry Knowles <knowlesjv087@...> wrote:


Thanks everyone for your great advice.  Talked to Lifeline today and they said that it is best not to discharge below 50%.  Said at that rate could get about 1200 cycles, but at 80% could get maybe 300 cycles.  I have 200w of solar and a generator so doubt that I would need to draw down below 50%, since I probably won’t boondock for more than a few days in any 1 place or if longer it would be in full sun such as AZ or Utah.

Interesting on the Interstates.  I’m on my 3rd set in less than 3 years the last set being replaced under warranty from Costco.  I have an unexplained draw.  With all of my fuses out and the propane off I still draw .8 amp as measured by my battery monitor.  I’ve been working with fellow group member Dee Riby to try and figure this out And we are at a loss.  Also enlisted my son who works with electronics and he is at a loss.  Talked to a tech at Winnebago who says that the .8 with all fuses out is normal, that if they have a coach on the lot with the battery switch on they will discharge completely over the weekend.  With all fuses in and propane on and nothing else I draw 1.3 amps.  It seems that I need to live with this, hence my seeking to upgrade my batteries.
Thanks again for all of your help on this.
Jerry K
2018J



On Oct 14, 2020, at 9:20 AM, Dick Stevenson <alchemy128@...> wrote:



Hi Jerry,
No experience with Trojan, but in the long-distance live-aboard sailing world where one is living off DC for long periods, Lifeline AGMs seem to be the batteries most discerning cruisers choose. They are, I believe, the only AGMs that allow for equalization which will extend a battery’s life. That, I believe, is possible because of the quality and robustness of the build.

And AGMs are lead acid/electrolyte batteries. I suspect you are referring to wet cell batteries, either maintenance free or the ones where you can add water or electrolyte.

AGMs (and gels) are likely to tolerate an 80% discharge better than most wet cells but neither will like that degree of depletion: the deeper depletion (>50%) the shorter the life span and the fewer charge cycles. Your Interstate batteries may only tolerate a few depletions to 80% before ready for the graveyard.

Decent prices on AGM Lifeline batteries can be (or used to be) found at West Marine or Defender Ind. Although now that battery stores seem to abound, they may be the most competitive.

One caveat for AGMs when boondocking for longer periods: they like to be fully charged every couple of weeks, sometimes not so easy to come by off the grid and charging from 50% depleted to 80%. That last 20% is hard to come by unless there is good solar and sun.

My best, Dick Stevenson


Dunc 18ND W.CO
 

.8 amps (9.6 watts @ 12V) is far greater than USB or HDMI splitters should draw. Both can be easily measured using a regular ammeter in series or a clamp on type. You can also simply disconnect these suspected phantom loads and watch your battery for load changes.

I also had experience with depleted AGM batteries that could not be resurrected to full capacity, even with good desulfating charger.

With any battery system, regardless of charging method, you can easily calculate how long your batteries will last using known loads and estimated hours of use. You can also measure depletion rate of any battery to determine whether it is "up to spec". From these known data points, you can calculate whether new batteries, or a change over to lithium, is worth it to you.
--
Dunc, W.CO, 2018 N24D
800W Solar, 10kWh Tesla Coach
Gyrocopter Toad


Richard Filcoff
 

Interesting that Trojan stated that discharging to 80% could get maybe 300 cycles.  Most of the related sites with which I am familiar, such as Battery University, indicate that if discharge every time to 20% S.O.C., you would reduce the cycles to about half of the number of cycles that you would obtain if discharge to 50% S.O.C. Battery University also indicates that the amount of time the battery is allowed to stay in the discharged state is a significant cause of the detriment to battery capacity.

In either case, it’s clear that if you need the energy that is provided discharging to 20% S.O.C, the economics and impact on your weight carrying capacity may be such that staying with two AGM batteries and discharging them to 20% S.O.C. may work for you.  It would take 3.2 AGM’s discharged to 50% to provide the amount of energy that 2 AGM’s discharged to 20% provide.  You would have to determine where to mount the extra battery and how to get wiring to it.  I suspect your original convertor/charger would still work for 3 AGM’s, but would be sub-optimal for 4 AGM’s.  Few people would want to take to hit to cargo carrying capacity that would result from adding 2 AGM’s

The total cost, in terms of the Casea#1, total amount of energy provided by the batteries, of achieving this extra capacity equivalent to discharging to 20% S.O.C. are, depending upon whose number of cycles you use, as follows:

Case#1, per Trojan: Reduce cycles from 1200 to 300: (50%/80%) X 4 = 2.5 X cost of staying with 2 batteries and discharging to 50% S.O.C.

Case#2, per Battery University, reduce cycles from 1200 to 600: (50%/80%) X 2 = 1.25 X cost of staying with 2 batteries and discharging to 50% S.O.C.

Case#3: Add 1.2 batteries: 1.2X plus installation cost, which varies depending upon whether DIY or pay someone to install an additional battery (or 2 additional batteries).  Also, whether a new convertor/charger is needed.

A factor not included in the above calculations is that it is highly unlikely that every cycle would discharge the batteries to 20% S.O.C.  Therefore, the degradation in battery capacity that results from discharging to 20% S.O.C. would have less of a detrimental effect than shown for Case#2.

Conclusion: I’m staying with 2 batteries and may occasionally discharge well below 50%. Also note that I have a 30 month full replacement warranty on my batteries. YMMV.

Rick Filcoff

From: discussion@view-naviontech.groups.io <discussion@view-naviontech.groups.io> On Behalf Of Jerry Knowles
Sent: Thursday, October 15, 2020 12:20 PM
To: discussion@view-naviontech.groups.io
Subject: Re: [view-naviontech] Trojan AGMs

 

Thanks everyone for your great advice.  Talked to Lifeline today and they said that it is best not to discharge below 50%.  Said at that rate could get about 1200 cycles, but at 80% could get maybe 300 cycles.  I have 200w of solar and a generator so doubt that I would need to draw down below 50%, since I probably won’t boondock for more than a few days in any 1 place or if longer it would be in full sun such as AZ or Utah.

 

Interesting on the Interstates.  I’m on my 3rd set in less than 3 years the last set being replaced under warranty from Costco.  I have an unexplained draw.  With all of my fuses out and the propane off I still draw .8 amp as measured by my battery monitor.  I’ve been working with fellow group member Dee Riby to try and figure this out And we are at a loss.  Also enlisted my son who works with electronics and he is at a loss.  Talked to a tech at Winnebago who says that the .8 with all fuses out is normal, that if they have a coach on the lot with the battery switch on they will discharge completely over the weekend.  With all fuses in and propane on and nothing else I draw 1.3 amps.  It seems that I need to live with this, hence my seeking to upgrade my batteries.

Thanks again for all of your help on this.

Jerry K

2018J

 



On Oct 14, 2020, at 9:20 AM, Dick Stevenson <alchemy128@...> wrote:



Hi Jerry,
No experience with Trojan, but in the long-distance live-aboard sailing world where one is living off DC for long periods, Lifeline AGMs seem to be the batteries most discerning cruisers choose. They are, I believe, the only AGMs that allow for equalization which will extend a battery’s life. That, I believe, is possible because of the quality and robustness of the build.

And AGMs are lead acid/electrolyte batteries. I suspect you are referring to wet cell batteries, either maintenance free or the ones where you can add water or electrolyte.

AGMs (and gels) are likely to tolerate an 80% discharge better than most wet cells but neither will like that degree of depletion: the deeper depletion (>50%) the shorter the life span and the fewer charge cycles. Your Interstate batteries may only tolerate a few depletions to 80% before ready for the graveyard.

Decent prices on AGM Lifeline batteries can be (or used to be) found at West Marine or Defender Ind. Although now that battery stores seem to abound, they may be the most competitive.

One caveat for AGMs when boondocking for longer periods: they like to be fully charged every couple of weeks, sometimes not so easy to come by off the grid and charging from 50% depleted to 80%. That last 20% is hard to come by unless there is good solar and sun.

My best, Dick Stevenson