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Topic: Preventative maintenance and possible battery upgrade  (Read 3224 times) previous topic - next topic

Re: Preventative maintenance and possible battery upgrade

Reply #50
I spoke with the guy with the magnum inverter today.  We talked for about 30 minutes on the phone and he seemed like a trustworthy guy. 

He removed the Magnum because he switched to two Tesla model S batteries creating a 48V battery bank.  The magnum charger wouldn't work for the Tesla batteries. 

The reason for the extra $200 is because the inverter is in dry storage that's not close to him.  If he had to meet up with the potential buyer and assist in the setup for testing then it would cost extra.  He has someone available to meet for purchasing if we decide to not have his assistance.  Idk it might be legit, it might not. 

Included with the inverter is the magnum ME-ARC remote control panel and the magnum AGSN auto generator start. 

We haven't decided on anything yet because we still have to figure out how and where we can even dry camp.  It's something we haven't done before so we're a little nervous about it.  A $1500 investment could pay for itself rather quickly but we actually have to figure out how to get it to.
Hannah and Tyler Phillips
1993 U280 Grand Villa AKA Pearl
Basement Air
Cummins 6CT8.3
Build Number 4196

Re: Preventative maintenance and possible battery upgrade

Reply #51

Included with the inverter is the magnum ME-ARC remote control panel and the magnum AGSN auto generator start. 

We haven't decided on anything yet because we still have to figure out how and where we can even dry camp.  It's something we haven't done before so we're a little nervous about it.  A $1500 investment could pay for itself rather quickly but we actually have to figure out how to get it to.

If you can spend $500 and not expect anything but a life experience either good or bad I say go to it.  If you can disconnect your batteries overnight and not have the voltage decrease, live with the batteries you've got right now.  It's more important to upgrade your battery charging system first.

Dry camping depends on your willingness to be awakened in the middle of the night by a knock on the door.
1992 Foretravel Grand Villa
U225 SBID Build No. 4134
1986 Rockwood Driftwood
1968 S.I.A.T.A. Spring
1962 Studebaker Lark
1986 Honda VF700C
1983 Honda VF750C
Charlie, the Dog was broken out of jail 24 Oct 2023
N1RPN
AA1OH (H)e who must be obeyed.

Re: Preventative maintenance and possible battery upgrade

Reply #52
If you can spend $500 and not expect anything but a life experience either good or bad I say go to it.  If you can disconnect your batteries overnight and not have the voltage decrease, live with the batteries you've got right now.  It's more important to upgrade your battery charging system first.

Dry camping depends on your willingness to be awakened in the middle of the night by a knock on the door.

We're trying to weigh all of our options.  I feel like the only way I really learn anything is by making bad choices and having to deal with the consequences.  Unfortunately it seems like I have to make the same bad choices several times before learning to do otherwise.  Haha

Do you mean to disconnect the charger and try using the batteries over night? 
Hannah and Tyler Phillips
1993 U280 Grand Villa AKA Pearl
Basement Air
Cummins 6CT8.3
Build Number 4196

Re: Preventative maintenance and possible battery upgrade

Reply #53
Whether you dry camp or not you still need a good charging system,a pure sine wave is a good choice.
96 U270 BUILD 4810
85 380SL
Drummonds TN.

Re: Preventative maintenance and possible battery upgrade

Reply #54
They say the definition of insanity is doing the same thing over and over expecting a different outcome
Chris
1999 U 320 DGFE
Build Number 5523
Chris & Elka Lang
In the field, Lonoke AR

Re: Preventative maintenance and possible battery upgrade

Reply #55
That's a excellent value
"Riding and rejoicing"
Bob & Susan
1997 U320 40' Mid entry, build 5132,  wtbi ce27, 4th owner
2007 Solara convertible
2 prodeco tech outlaw ss electric bikes

1095 watts solar
08 Ls 460 and a sc430
2000 Ford F-250 superduty 4x4

Re: Preventative maintenance and possible battery upgrade

Reply #56
The propane, smoke,and other alarms may be powered by those batteries, not the best choice to disconnect.
96 U270 BUILD 4810
85 380SL
Drummonds TN.

Re: Preventative maintenance and possible battery upgrade

Reply #57
We're trying to weigh all of our options.  I feel like the only way I really learn anything is by making bad choices and having to deal with the consequences.  Unfortunately it seems like I have to make the same bad choices several times before learning to do otherwise.  Haha

Do you mean to disconnect the charger and try using the batteries over night? 
Close.  Disconnect the batteries or at least one battery and see if it's voltage drops over night.  This will tell you if it is internally shorted.

John44 made a valid point about the propane alarm being off line, but without electricity so will the propane.

The best learning comes after you break something.

The fun begins after the bad decision has been executed.
1992 Foretravel Grand Villa
U225 SBID Build No. 4134
1986 Rockwood Driftwood
1968 S.I.A.T.A. Spring
1962 Studebaker Lark
1986 Honda VF700C
1983 Honda VF750C
Charlie, the Dog was broken out of jail 24 Oct 2023
N1RPN
AA1OH (H)e who must be obeyed.

Re: Preventative maintenance and possible battery upgrade

Reply #58
Here we go. IF you decide to do some upgrades in the future.
Having a little experience in the past with this issue. I'd recommend most of what others have mentioned.
1. Replace the old "dumb" charger with an Inverter Charger, either a Victron, Magnum or if on a budget AIMS. Just make sure it's a Pure Sine Wave Inverter. Even if you only need a charger for now, better IMHO to get it all-inclusive as you can turn off the inverter until needed

2. Buy the best batteries you can afford. My personal preference for reasonably priced batteries is Lifeline AGM's (50% Usable AH), or go with Battle Born Lithiums if you have the cash. (Escapees/Xscapers have discounted pricing) They can run 100% down with no damage (waiting for hate mail now).

3. As far as solar, I've had a great experience with AM solar authorized installer. RV Solar Solutions, who roams around the country, and I also know 2 other guys which I have trust with. I know them personally they do great work and also travel the country. Call Cameron at Lithium Battery Installation | Off The Grid Camper I think they are in Florida now. and also Andrew at https://www.facebook.com/pullensolar/ he did some final hookups for my Promaster Camper Van traveling in ABQ after I had purchased the components and mounted them on a backplane.

Good luck to you there are many resources to help you!
Prior 2003 U295  40ft  400Hp -Sold
2020 F350 Tremor - Sold
2021 Bundutec Roadrunner - Sold
2017 Airstream Classic - Sold that POS
2017 F250 - Sold
2019 Sprinter Van - Sold
2022 Winnebago Revel 4x4


Army Airborne Vet.

Re: Preventative maintenance and possible battery upgrade

Reply #59
I've been doing some studying over the past few days.  I don't think we're going to go with the CL magnum based solely on our not so stellar track record.  It might be a good deal but it also might be a $500 paperweight. 

If we do go with anything it'll probably be the O'Reilly AGM batteries and the Xantrex inverter/charger.  We don't want to wrap a whole bunch of money into this project for several reasons.  I feel like that combo will get us to a good starting point.  We'll probably purchase the Victron 712 monitor as well.

We're still in research mode for the time  being but I really appreciate everyone's advice. 

I've been trying to figure out how long it would take to charge two 250ah agm batteries from %50 dod with the generator and the 80amp charger.  Does anyone know about how long it would take?

Also does the inverter/charger use the same 4/0 cables for suply and charge?  Probably a dumb question but I don't know.
Hannah and Tyler Phillips
1993 U280 Grand Villa AKA Pearl
Basement Air
Cummins 6CT8.3
Build Number 4196

Re: Preventative maintenance and possible battery upgrade

Reply #60

2. Buy the best batteries you can afford.


If we could afford it I'd go with a pair of Tesla batteries.
Hannah and Tyler Phillips
1993 U280 Grand Villa AKA Pearl
Basement Air
Cummins 6CT8.3
Build Number 4196

Re: Preventative maintenance and possible battery upgrade

Reply #61
Hanna and Tyler, I hope this helps.  My "guess" to answer your question of how long to charge two 8ds, from 50% to 100% state of charge, with an 80 amp smart charger, is the following, 5 hrs (to 90%). In real life you will only probably go to 80-90% as the topping off would take to long. The topping off will be done when you are plugged in. East Penn is saying 4.8 hrs to take one battery from 0-90%.  So let's use round numbers, two 8ds 9.6 hours, from 50-90%, 5hrs.

And so....since in an earlier responce you said,
"As far as electricity consumption, we really don't use all that much because all of our lights are LED and we can run the refrigerator and furnace off of propane if need be.  Other than using a laptop during the day for Hanna's job and in the evening for shows we don't use much electricity."

I believe your goal to run the generator ⁷each day less than 2hrs is a real possibility.  Especially with the Victron 712, you will easily, on your phone, see the net # of how many amps you are putting in and how many you are using.  I learned along time ago, "it is difficult to improve, what you do not measure."  This data will help you conserve electricity.

For the most useful information, check out the following Lifeline Technical Manual, "charging" section, page 19, of this Lifeline manual.  Although not the brand you are buying, I've used this as my agm bible now for over 10 years. I'd ignore the section on conditioning or equalization as this is specific to Lifeline. The Lifeline manual recommends a 100 amp charger minimum, for two 250 amp lifelines if you plan on going below 50% depth of discharge.  I think you will be fine with the 80 amps, as you stated you plan on charging from 50 to 100% charge.  I charge my 3 8Ds with 100 amps and I also never go below 50% state of discharge. East Penn even gives data with less than an 80 amp charger to calculate charge times.

Check out page 3, chart B, from East Penn file 0139.pdf below.  "For example, to charge an 8G8D (curve H) to 90% in 3.5 hours, 100 amperes are required; at 35 amperes, it would take 10 hours".
Double the times for two batteries.
97 U295 40, Build #5040, 6C8.3 325 HP
Oregon Continuous Traveler
Samsung Residential #RF20HFENBSR,
Xantrex SW2012, (3)AGM8D Hse, (2)AGM Grp24 Eng, Victron BMV-712, 1800w Solar 4 LG & 2 Sunpower
Extreme Full Body Pt w/hdlmps, new furn/floor, 4 down Lexus 2004 GX470 AWD curb weight 4,740 lbs
Prev: 1990 Barth, 10L 300 2 yrs; 91&92 Monaco Signature, 10 yrs, 10L C 300 &  6C8.3 300; 1997 ForeT 6C8.3 325 since May 2017.  Employed by Guaranty RV 14+ yrs.  Former VW New Car Dlr/Service Dlr, Sales Mgr, Rv Sales, and Service Adviser from 1968-2017
"Don't criticize what you can't understand" Bob Dylan

Re: Preventative maintenance and possible battery upgrade

Reply #62
I've been doing some studying over the past few days.  I don't think we're going to go with the CL magnum It might be a good deal but it also might be a $500 paperweight.

Good decision. 

If we do go with anything it'll probably be the O'Reilly AGM batteries and the Xantrex inverter/charger.  We don't want to wrap a whole bunch of money into this project for several reasons.  I feel like that combo will get us to a good starting point.  We'll probably purchase the Victron 712 monitor as well.

Your money, your choice.  And it's a good choice.

We're still in research mode for the time  being but I really appreciate everyone's advice.

This is going to be fun.

I've been trying to figure out how long it would take to charge two 250ah agm batteries from %50 dod with the generator and the 80amp charger.  Does anyone know about how long it would take?

DOD is the department of defense.  We use State of charge, SOC.  50% SOC.

The short answer from Mr. Lewis' detailed answer is 4 hours.  As is it takes 4 hours to charge your battery from 0% SOC to 80% SOC IF your charger can supply the current for which the battery asks.

Also does the inverter/charger use the same 4/0 cables for supply and charge?  Probably a dumb question but I don't know.

Yes you use the same cables.  The electrons can flow in both directions through the same conductor at the same time but we don't want to talk about that.
No questions are dumb.

1992 Foretravel Grand Villa
U225 SBID Build No. 4134
1986 Rockwood Driftwood
1968 S.I.A.T.A. Spring
1962 Studebaker Lark
1986 Honda VF700C
1983 Honda VF750C
Charlie, the Dog was broken out of jail 24 Oct 2023
N1RPN
AA1OH (H)e who must be obeyed.

Re: Preventative maintenance and possible battery upgrade

Reply #63
Lifeline agm's less resistance internal connections charge 20% faster.  So figure that in if using their chart? 

I am hesitant to use non lifeline agm's as any long term variation from  the recommended 20% of capacity or 5% charge rates would seem to damage the plates permanently. 

Gels are not as affected.  Hence Foretravels use of mk gels in every unicoach made. 

I would love to see a capacity test done here on various batteries after x number of years use. 

Obviously non used coaches plugged in would show the best life possible per the type.

I bought a couple of variable load test setups that I used to verify my prepper type battery/inverter packs(4Patriot) actual capacity that are adjustable up to a constant 20amp load.

Timing each battery separately should show exact capacity? 

I have a double set of inline gauges that show exactly how much power went through them.  Neat stuff. 

The discharge load testers are separately powered by 12 volt plus or minus 5% for accuracy.

Some shops have battery testers that print out results but I assume these are fairly expensive?

Not sure if they work as well as an actual long term load tester?  Plus the inline gauge does verify the testers loads as accurate.

You cannot be too "trick" in my mind about rv batteries and electrical systems.

The coach is a 12volt system to start with

No my tester is not UL listed.  Shame on me.  Haha. 
"Riding and rejoicing"
Bob & Susan
1997 U320 40' Mid entry, build 5132,  wtbi ce27, 4th owner
2007 Solara convertible
2 prodeco tech outlaw ss electric bikes

1095 watts solar
08 Ls 460 and a sc430
2000 Ford F-250 superduty 4x4

Re: Preventative maintenance and possible battery upgrade

Reply #64
I was reading an article on agm batteries that said that they could be safely charged at a C/4 rate which is ah rate divided by 4.  I guess that would mean that two 250ah batteries could safely be charged at 125 amps?  Idk if I was understanding that correctly but that would mean 80 amps is well within a safe zone for charging.

For a two battery setup where would the shunt go for the battery monitor?
Hannah and Tyler Phillips
1993 U280 Grand Villa AKA Pearl
Basement Air
Cummins 6CT8.3
Build Number 4196

Re: Preventative maintenance and possible battery upgrade

Reply #65
I was reading an article on agm batteries that said that they could be safely charged at a C/4 rate which is ah rate divided by 4.  I guess that would mean that two 250ah batteries could safely be charged at 125 amps?  Idk if I was understanding that correctly but that would mean 80 amps is well within a safe zone for charging.

For a two battery setup where would the shunt go for the battery monitor?
The max charge current of any battery will be determined by the battery manufacturer and can vary dramatically from one manufacturer to the next, even when discussing similar types of battery like AGM, Gel, etc, so always defer to the manufacturer's recommended charge rates regardless of any articles that you may read (unless it's an article written by the manufacturer, of course!)

When parallel-connecting two or more batteries (assuming keeping your native voltage at 12v), you should have your positive takeoff from the first battery and your negative takeoff from the last battery (or vice-versa, just don't pull your POS and NEG off the same battery) and the shunt will go inline with one of those takeoffs. Most battery monitors of which I'm aware use a NEG shunt, so in that case your single NEG takeoff from your battery bank will go to the "battery" side of the shunt and all your other system NEGS (chargers, loads, chassis grounds, etc) will connect to the other side of the shunt (on the BMV-712, this is labeled "loads and chargers"). It will of course be very important to ensure that no system NEGs connect directly to the battery, as the shunt won't be able to "see" anything that's bypassing it.



Technical Support Manager and official poker of electronics at Laurel Technologies / Bay Marine Supply. Distribution and expert support of Victron Energy, Sterling Power, Blue Sea, Bussman, and Battle Born products.

Re: Preventative maintenance and possible battery upgrade

Reply #66
I was reading an article on agm batteries that said that they could be safely charged at a C/4 rate which is ah rate divided by 4.  I guess that would mean that two 250ah batteries could safely be charged at 125 amps?  Idk if I was understanding that correctly but that would mean 80 amps is well within a safe zone for charging.

For a two battery setup where would the shunt go for the battery monitor?
Shunt must be between both battery negatives and loads and charging sources.
Jim C.
coachfree, previous 1997, 1999, 2000, and 2003 Foretravels.

Re: Preventative maintenance and possible battery upgrade

Reply #67

For a two battery setup where would the shunt go for the battery monitor?


In the main line to the battery so that all the electricity going in or out goes through the shunt.  Keep in mind that the shunt is a precision resistor and does get warm in use.  The shunt is usually sized 2X the maximum expected continuous current.

In my last installation I installed the shunt in the charging line as I only wanted to monitor charging current.  I used that and a dedicated 12 VDC led voltmeter to monitor my battery condition.  Along with a paper memory taped to the refrigerator door.
1992 Foretravel Grand Villa
U225 SBID Build No. 4134
1986 Rockwood Driftwood
1968 S.I.A.T.A. Spring
1962 Studebaker Lark
1986 Honda VF700C
1983 Honda VF750C
Charlie, the Dog was broken out of jail 24 Oct 2023
N1RPN
AA1OH (H)e who must be obeyed.

Re: Preventative maintenance and possible battery upgrade

Reply #68
Absolutely, the shunt is between the negative terminal of the battery where you connect the cable for house ground and the house ground. So, short battery cable of same gauge as chassis ground cable going from negative terminal to shunt and old coach ground wire to other terminal of the shunt.

And, as already described, the positive will come off the other battery so the electrons flow through all batteries.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Preventative maintenance and possible battery upgrade

Reply #69
I feel like such a dummy when it comes to all of this.  I can read and reread the information a 100 times and come out blank in the end.  Unless it's in front of me and I can physically lay hands on it it's hopeless.  I've taken classes, was an electricians apprentice for a year and installed instrumentation and electrical equipment on natural gas pipelines for two years so I can understand how it works.  I just don't know why it's not sinking in, maybe because there's too many variables.
Hannah and Tyler Phillips
1993 U280 Grand Villa AKA Pearl
Basement Air
Cummins 6CT8.3
Build Number 4196


Re: Preventative maintenance and possible battery upgrade

Reply #71
The videos that have been posted are really helpful. The DIY solar guy posted a video about how his income stream works and although its not related to the topic it was interesting.  He said he brings in around 50k per month with advertisers and affiliated marketing! 

I thought making 50k per year was good, I can't imagine making that per month.  I really need to become a youtube influencer hahaha.
Hannah and Tyler Phillips
1993 U280 Grand Villa AKA Pearl
Basement Air
Cummins 6CT8.3
Build Number 4196

Re: Preventative maintenance and possible battery upgrade

Reply #72
That Victron 712 is a great unit. Personally we don't like a ton of gauges inside (though some like the airplane cockpit look) so the Bluetooth makes it great for us. The monitor is mounted on a 4 SQ electrical box underneath. I just check my phone if I need status..Used it on a previous rig, now on our Camper Van, and I'll install on the FT once we change out our batteries, (we know they are old already) to new Lithiums
Prior 2003 U295  40ft  400Hp -Sold
2020 F350 Tremor - Sold
2021 Bundutec Roadrunner - Sold
2017 Airstream Classic - Sold that POS
2017 F250 - Sold
2019 Sprinter Van - Sold
2022 Winnebago Revel 4x4


Army Airborne Vet.

Re: Preventative maintenance and possible battery upgrade

Reply #73
I've  spent the last week studying the coach wiring schematics, tracing wires and reading the installation manual for the Xantrex inverter/charger to try and get a better understanding of what's going on with the system before we move forward.  A lot of questions I had have been answered by taking the time to study the information I have, but there is still a few things I haven't been able to fully figure out.

One of the schematics I've been studying is the one for the manual transfer switch.  I understand how it works and know it won't be used for the new inverter but that is where the question comes into play.

There are two contactors in the MTS powered by either the AC input from the inverter or by shore power.  When the inverter is in use there is one 120v line that is split between the two contactors and depending on which circuit is selected by the control panel is the the contactor that is active. Got it.

When connected to shore power both of the contactors are active completing the path for both circuits.  Simple enough.  And when shore power is present the path to the inverter is broken which prevents current from back feeding into it. 

When installing the new inverter is there a need to install a similar setup to prevent current from back feeding into it when connected to shore power? 

I'm trying to visualize and understand how the whole system operates and it's pretty involved (at least for me) so it's very possible that I'm just misunderstanding.
Hannah and Tyler Phillips
1993 U280 Grand Villa AKA Pearl
Basement Air
Cummins 6CT8.3
Build Number 4196

Re: Preventative maintenance and possible battery upgrade

Reply #74
Manual transfer switch?? Are you sure it isn't the standard ATS (Automatic Transfer Switch)?

And, yes, you will wire the new inverter exactly the same way.  If one hot from inverter wire it to both "IN's" on the transfer switch.

If two hots, wire each to a different "IN".
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020