Which 6 volt AGM batteries to choose?

[rbryan4]

Originally Posted by kfsmith

Interstate 6V AGM way cheaper than Trojan with the same specs. We are really happy with ours! We bought ours in the states and took them up to BC.

Interesting. Comparing a 210aH Interstate AGM to a 217aH Trojan AGM, I've found the Trojans less expensive - at least online.

[grantpallen]

I picked up a pair of 6v from Canadian Tire, installed by ETI in May 2018. They are then warrantied by them accross Canada.

[poodlespal]

Thanks to everyone who took the time and shared their expertise on this issue. We decided to go with the Life Line GPL-4CT from Battery Guys
in Arizona. Price was $324.99 with free shipping and no sales tax. ETI approved them.

[Brian B-P]

A pair of Lifeline GPL-4CT don't need any relocation, but just in case anyone is interested...

Originally Posted by rbryan4

... just thinking out loud, I suppose you could mount them under the queen bed in the rear instead, and run some very long and THICK battery cables underneath the trailer along the frame rail. But now you're shedding 125 lbs of tongue weight and adding 240 lbs on the rear. Hmm. First world problems.

The less extreme approach - rather than replacing a moderate mass of battery at the very front with a huge mass of battery near the back - would be to put the heavier set of batteries under the curbside bench of the dinette. That location is closer to the middle (while still being ahead of it), so could accommodate substantially higher battery mass with little change to tongue weight... and a more central mass distribution for stability. This location was previously used by Escape, and Dave relocated his batteries there.

[rbryan4]

Originally Posted by Brian B-P

The less extreme approach - rather than replacing a moderate mass of battery at the very front with a huge mass of battery near the back - would be to put the heavier set of batteries under the curbside bench of the dinette. That location is closer to the middle (while still being ahead of it), so could accommodate substantially higher battery mass with little change to tongue weight... and a more central mass distribution for stability.

Ideally, something that heavy should be mounted amidships, and centered, but there's this thing called the floor in the way.

Presuming such a battery would fit inside the benches at just under 16 inches tall, wouldn't having 240 lbs on one side and none on the other make the trailer list a bit?

[Perry Butler]

Originally Posted by poodlespal

Thanks to everyone who took the time and shared their expertise on this issue. We decided to go with the Life Line GPL-4CT from Battery Guys
in Arizona. Price was $324.99 with free shipping and no sales tax. ETI approved them.

Is that price individually or for the pair?

We'll be heading to ETI with two PS/CROWN AGM 6CRV220's costing $462 for the pair ($231 each) shipped to our door.

Enjoy,

Perry

[John in Santa Cruz]

and I replaced the dead Interstate GC-2's in my E21 with a pair of Costco-Interstate GC-2 for about $200 total. they are only 210AH instead of 225AH liek the more expensive ones, but 15AH doesn't get you very far.

[Brian B-P]

Originally Posted by rbryan4

Ideally, something that heavy should be mounted amidships, and centered, but there's this thing called the floor in the way.

... wouldn't having 240 lbs on one side and none on the other make the trailer list a bit?

Yes, but there are a bunch of components to consider. The water heater (72 pounds full), refrigerator, black waste tank, furnace, and power centre (and usually microwave oven) are all on the other extreme side of the trailer, so I wouldn't be surprised if it is street-side-heavy in stock form. Few owners (of any model, any brand) actually measure the left-to-right weight distribution.

Under the floor could actually work, especially with AGM batteries (which can be mounted on their side) and with lithium batteries built up from common individual cells, but not with batteries of these proportions.

Originally Posted by rbryan4

Presuming such a battery would fit inside the benches at just under 16 inches tall...

That's a good catch - available height is a concern, as shown by the problems getting a good lid on a battery box over typical GC2 batteries and still fitting it under a seat. On the other hand

• the bed is likely the same height as a dinette seat would be in the same location (right?), and
• the frame steps three inches up at the back in the 19', so there should be more height available at the front if the stock bed and stock dinette seats are the same height above the floor,

... so maybe the bed and dinette are similarly unworkable for very tall batteries, and both viable for more typical models.

With narrow and tall batteries it might even be possible to cut into the plywood floor to mount them outboard and lower than the general floor level (while hopefully still within the dropped part of the shell), especially with the current body style and its vertical side.

[rbryan4]

Those batteries would probably fit fine under the bench in my particular trailer, because I had them raise the dinette benches and center floor area 4 inches. This left the underseat area 4 inches deeper than stock.

No, I'm not getting them.... [emoji23]

I would however consider the Fullriver DC250-6 AGMs. Similar size to my Flooded Cell Interstates so they fit in the storage box, but AGM and 250 amp hours. Would add about 30 lbs to the front, which is workable.

[Andrea]

Originally Posted by poodlespal

Thanks to everyone who took the time and shared their expertise on this issue. We decided to go with the Life Line GPL-4CT from Battery Guys
in Arizona. Price was $324.99 with free shipping and no sales tax. ETI approved them.

Hello
Did they ship your 2 Lifeline batteries to Escape?
Or are you taking them with you when you pick up your trailer?
I’m looking for AGM batteries also for a December pick up
Thank you !
Andrea

[AdobeMatt]

I’ve tried a pair of Optima yellow AGM ($$$). They didn’t last any longer, weren’t any lighter, but cost 50% more. My two Interstate GC FLA ($$) need to have water levels topped up every 3 months though. Lithium-polymer are considerably lighter and more forgiving of discharging but much more expensive for now ($$$$$)

[rbryan4]

Originally Posted by AdobeMatt

I’ve tried a pair of Optima yellow AGM ($$$). They didn’t last any longer, weren’t any lighter, but cost 50% more. My two Interstate GC FLA ($$) need to have water levels topped up every 3 months though. Lithium-polymer are considerably lighter and more forgiving of discharging but much more expensive for now ($$$$$)

Optima batteries are more geared to the automotive industry. Even their "deep cycle" batteries focus on cold cranking amps, a stat which is irrelevant to a trailer application. I would stick with batteries designed for RV or Solar applications with an emphasis on Amp Hours, not CCA's.

[Brian B-P]

Originally Posted by AdobeMatt

I’ve tried a pair of Optima yellow AGM ($$$). They didn’t last any longer, weren’t any lighter, but cost 50% more.

That should be expected. The advantages of AGM are in lack of maintenance, plus other features not very relevant to travel trailers. The energy storage depends basically on the amount of lead, so AGM batteries are not lighter than flooded batteries of the same capacity.

Originally Posted by AdobeMatt

Lithium-polymer are considerably lighter and more forgiving of discharging...

While the ability to fully discharge lithium batteries is often claimed as a major advantage, and routinely cycling them to a low state of charge (maybe 20%?) doesn't reduce life the way it does with a lead-acid battery, they are absolutely intolerant of complete discharge. It's easy to destroy any lithium battery, by simply fully discharging it; that's one reason that electric vehicles have sophisticated battery management systems (BMW), and even a lithium battery for an RV typically has at least a basic built-in BMS.

Also, the "lithium" batteries sold for RV use are usually lithium iron phosphate (LiFePO4, or "LFP") - which means that the cathode is LiFePO4 - because they are easiest to manage and least likely to burst into flames (yes, that's a real problem with other types). "Lithium-polymer" means that the electrolyte is a conductive polymer - nothing to do with the cathode material - rather than the usual liquid. While common in mobile devices, lithium-polymer batteries are rare in large sizes, and a battery sold for RV use will not likely be of this type. That's good, because they are notorious for that bursting-into-flames problem.

The units from Battle Born that have been discussed in this forum before are examples of LiFePO4 batteries with a built-in BMS.

[Chuckster]

Originally Posted by Perryb67

Is that price individually or for the pair?

We'll be heading to ETI with two PS/CROWN AGM 6CRV220's costing $462 for the pair ($231 each) shipped to our door.

Enjoy,

Perry

Hi Perry,
Are you planning to use the Escape provided GoPower charge controller with the Crown AGM’s? I was planning on doing the same and the Crown rep did not like the 30 minute bulk/ absorption charge parameter, saying they need 90-120 min. I have asked for the complete profile needed.

Chuck

[Andrea]

ETI recently approved Life Line GPL-4CT for our Escape 21, Thanks for the info on this forum.

[Perry Butler]

Originally Posted by Chuckster

Hi Perry,
Are you planning to use the Escape provided GoPower charge controller with the Crown AGM’s? I was planning on doing the same and the Crown rep did not like the 30 minute bulk/ absorption charge parameter, saying they need 90-120 min. I have asked for the complete profile needed.

There is nothing magical or different about the AGM batteries from different companies. They all work the same. I'm not worried about leaving Chilliwack with a GoPower charge controller on our Crown batteries, anymore than I would if I'd came with Trojan or Lifeline AGM batteries.

We will be using the GoPower controller and see how it handles our system. It's a cheap, basic system, and we understand that ETI will deduct $50 if you don't want the GoPower, but we would need to immediately install another system before traveling south for six weeks enjoying Washington, Oregon, and northern California. That $50 is cheap to leave ETI with a working system. Rease will not debug another system of your choice and we understand his reasoning, that's why we'll initially use the GoPower.

If the GoPower works OK then we'll save our money, otherwise we'll be purchasing Bogart Engineering's SC-2030 charge controller and Trimetric 2030 battery monitor. We've already arranged for ETI to zip-tie our GoPower controller underneath the dinette bench, so no holes will be cut until I'm satisfied. Knowing me, I'll probably be installing the Bogart system this spring after we return from our pickup and Arizona trips. And yes, it will be a PITA to open our rear bench seat to see how the system is functioning.

Enjoy,

Perry

[AllanEdie]

Originally Posted by Chuckster

Are you planning to use the Escape provided GoPower charge controller with the Crown AGM’s? I was planning on doing the same and the Crown rep did not like the 30 minute bulk/ absorption charge parameter, saying they need 90-120 min. I have asked for the complete profile needed.

Chuck

If the controller you are referring to is only to control charging from solar panel(s), it will likely do the job if your loads are small enough, and you have sufficient exposure to direct sun on the solar panel(s). OTOH, you would be better off with a programmable MPPT controller which allows you to tailor the voltages and charge times to your specific battery bank. A fully programmable controller will allow you to tailor the charge times and voltages to ensure the best possible maintenance of your batteries. Further, an MPPT charger will more efficiently harvest power from your panels than the standard PWM controller will, and the good ones permit measurement of battery temperature to adjust charge voltages if you want that option.



For what it is worth, I went for a Victron MPPT 30 controller, and a Victron battery monitor. Both are "smart" and allow full programming and data access through apps on android or Apple devices. Initial testing confirms that everything works fine, but I have not spent enough time with them to do a detailed review, which I will try to do later.



Charging from the tow vehicle is another story, which I will also cover in detail later. At this point, I will just note that the 7 pin connection will not do the job properly, if at all, due to the low alternator voltages produced by modern alternator controllers in vehicles, exacerbated by voltage drop caused by the standard 7 pin and trailer wiring which is too small, especially in the Escape 21 given the wire run to the back of the trailer. Most current generation vehicles will produce only roughly 13.5v at the alternator once the vehicle is warmed up, and by the time you deduct 0.5v or more voltage drop (almost certainly more will be the norm when batteries are significantly discharged), only ~~13 volts will be left at the trailer battery which is nearly useless for charging a significantly discharged deep cycle bank. The only solution that I have found, if you want proper charging from the tug, is a BtoB charger which will raise the input voltages to appropriate charge voltages. OTOH, if your solar is sufficient, charging from the tug may not be needed. I opted to have both.



Good luck with your decisions.

[Perry Butler]

Originally Posted by AllanEdie

If the controller you are referring to is only to control charging from solar panel(s), it will likely do the job if your loads are small enough, and you have sufficient exposure to direct sun on the solar panel(s). OTOH, you would be better off with a programmable MPPT controller which allows you to tailor the voltages and charge times to your specific battery bank. A fully programmable controller will allow you to tailor the charge times and voltages to ensure the best possible maintenance of your batteries. Further, an MPPT charger will more efficiently harvest power from your panels than the standard PWM controller will, and the good ones permit measurement of battery temperature to adjust charge voltages if you want that option.

I agree with you on a programmable controller. However, arguing about MPPT vs PWM is like arguing Ford vs Chevy. They both can be programmable, have temperature sensors, and neither is the clear winner.

The GoPro is a simple controller and max's out at 14.4 volts. Both Trojan and Crown let you bulk charge your AGM's to 14.8 volts allowing the batteries to charge faster (couldn't find that spec on Lifelines website, but would believe it would be 14.8 also). I guess I will be purchasing Bogart's Trimetric Battery Management System.

Enjoy,

Perry

[rubicon327]

Wow. Too much information for most, but for the technical folks on the site this is a wealth of information on Lifeline AGM batteries:

http://lifelinebatteries.com/wp-cont...cal-Manual.pdf

[padlin]

Deleted.