To Keep or Not To Keep? AGM

B11 · April 2022

Changing to Lithium batteries. Should I keep and utilize the AGM batteries? If so, what have others done as a setup for both lithium & AGM use?
New 2022 400bd with rooftop and portable solar panels.

Denny16 · April 2022

Have you done much camping yet? I would wait to change out the battereis, your AGMs are new, and have 200+ amp hrs, of which a good 150AH is available to use. We find that our 200AH AGM is currently more than providing our camping needs whilst boondocking for 3-4 days. The solar panel keeps the AGM charged during the day and recovers the energy used at night. We have the older 2-way AC/DC fridge, and the solar keeps up,with its power draw.

Down the road, if you find you need additional battery power, then upgrade to Lithium batteries to fill that extra requirement. Lithium battery technology continues to improve, and prices are coming down. So waiting gives several advantages, along with a possible $ savings.
Cheers

bergger · April 2022

I agree with @Denny16. We have never come close to running out of power with our T@b 400 AGM batteries. The solar does a great job topping them off. I'd just use the AGMs for several years until you feel the need to replace them. Especially since they are brand new.

webers3 · April 2022

Also agree with @Denny16, do some camping first to get a feeling for how much power you are using, you maybe be surprised that what you have is quite adequate.

kottum · April 2022

I can't imagine combining lithium and AGM batteries on the same circuit. Quite different charging requirements and use characteristics. Sounds like trouble.

As for keeping the AGM's vs replacing them with lithium, it depends on you and where you live. While solar may keep up AGM's in Southwestern states, it would not be much help near Seattle, or camped in the woods of the East. I've have had some frustrating battery experiences traveling with AGM's and solar, in shaded campsites and cloudy weather.

We replaced the standard battery on our new T@b 320s BD with two 100 ah lithiums in the negotiations at purchase.

Doug

B11 · April 2022

Thanks, everyone. I greatly appreciate the feedback and responses.
This is all sound advice that I will heed and hold off on upgrading to lithium batteries for now. My thinking was based on the numerous posts I've read of boodockers encountering power issues due to the AGM's inferior depth of discharged range without the consequence of a considerable reduction in battery life. I think with the rooftop solar and added 230w portable solar panels, I will be in good shape. Our 400bd will have the west marine 2-way fridge which as I understand(also from posts on this fantastic forum) is very energy efficient.

Sharon_is_SAM · April 2022

@B11 - unless they changed, the frig is a 2 way Isotherm.

B11 · April 2022

@Sharon_is_SAM...Thanks, that was what I was referring to. The fridge is an isotherm. The nuCamp support staff member sent the following link to me which was a bit confusing coming from West Marine. Thanks for clarifying.

https://www.westmarine.com/buy/isotherm--cruise-130-elegance-silver-4-6-cu-ft-ac-dc-silver-door-3-sided-flange--14995229

Sharon_is_SAM · April 2022

That’s a big frig! I thought the 400 came with the Cruise Elegance 65?

Denny16 · April 2022

Unless nüCamp has made a major change, that Isotherm 130 is not the standard Isotherm 2-way fridge. The one being used previously was the Isotherm Elegance 65. The 160 would require some major cabinet changes, as you would loose the drawer under the fridge, and about 3-inches of width on the adjacent cabinet/drawer unit.

An AGM battery has a discharge level of 65-75%, better than the 50% discharge rate on lead acid batteries. So a 200AH AGM has about 140AH available for use, before requiring recharging.

Cheers

MarkAl · April 2022

I'm underpowered for only a rare long trip w/o sun with my 2 6V. They are my first in the trailer as my trainers. I will take them as low as AGM as I want to move to 2 Lithium but will wait for these to lose more capacity. I then plan to move them under a bench like the 400 to improve wire routing. Even going to Lithium I think there will be week+ times in the woods / winter / rain where I'll need a generator recharge.

B11 · April 2022

@Denny16 , @Sharon_is_SAM,
That’s interesting re the fridge. Below is the follow-up email from customer service at NuCamp when I inquired about the cancellation of the 3-way. I’ll follow up with NuCamp on Monday and let ppl know. Thanks again for all your insights. I truly appreciate everything.

Hi Brian,

Thank you for being a part of the nuCamp family.

Yes Norcold discontinued the 3-way fridge recently and did not give us any warning. As of now your unit is still scheduled to receive the 3-way fridge. In the event that your unit would not have the 3-way fridge we have a larger 2-way fridge that would go in the same space. The following website has more specifics on that fridge. https://www.westmarine.com/buy/isotherm--cruise-130-elegance-silver-4-6-cu-ft-ac-dc-silver-door-3-sided-flange--14995229

While its true that you will not be able to use propane, the newer fridge is very efficient. We have been using an Isotherm fridge in our 320 S for the past couple of years and it has been incredibly reliable. We have been very pleased with it's performance.

If you have any other questions please let us know.

Have a wonderful day,

Sharon_is_SAM · April 2022

Wow! No more large Norcold 3 ways in the 400. So the smaller frig is the Cruise Elegance 65 and the larger is the Cruise Elegance 130.

@B11 - you will need to tell us how you get along with the AGM batteries with this new frig with a reported 5 amp draw.

Denny16 · April 2022

OK, that makes sense, nüCamp is putting the new larger two-way in place of the large 3-way, in the former wardrobe locker on the TaB400.
Cheers

rh5555 · April 2022

Also, see my ancient post: https://tabforum.nucamprv.com/#/discussion/9940/agm-battery-depth-of-discharge-myth-busted. AGMs are almost as good as lithiums (if you can tolerate the weight).

B11 · April 2022

@rh5555 Thank you for that immensely in-depth data driven information. You clearly have a high level understanding of workings associated with battery usage. Appears from your findings, that AGM batteries can be discharged more than I thought. I'm an absolute less than novice when it comes to electricity(amps, volts, watts) understanding. Willing and able to learn but fully admit to not understanding the inner workings of solar, battery, generator, shore, and propane as they all pertain to the systems/items that draw power in the camper(mine[when I get it] is a 2022 400bd). I'd certainly like to feel more confident with how everything works for the main reason of not wanting to do damage to the expensive to me investment. I'd say I have a general overview at this point but definitely do not feel anywhere near confident that I understand nearly enough.
Thanks again for your input. I appreciate it.

B11 · April 2022

@Sharon_is_SAM
I'll most certainly keep record and post any info as I use the fridge/batteries.

DM159 · November 2023

Thank for starting this thread.

We have a 2022 TAB 400 with 2-6V AGM batteries and solar panels. We also have the Isotherm 3 way fridge. We use propane for the fridge when boondocking and it works great except above 5000'. We have used the fully charged AGM batteries over night boondocking above 5000' at 35 deg F but the battery draw is excessive to the point of a "low battery" error on the ALDE display and it quits heating.

So the answer to our concerns with the 2-6V AGM batteries is to upgrade with the 2 Lithium battery solution. That solution may also require a power converter change and a Lithium charger that will charge the Lithium batteries over 80%. Has anyone gone this route (WFCO WF-8955 LiS currently installed) and a Victron "Blue Smart" LiON charger?

manyman297 · November 2023

Does the 2022 models have propane refrigerators? I thought they ditched those.

As for lithium it depends on how you use the camper. If you’re usually plug into shore power then your AGMs would be fine. If you boondock a lot then the lithiums would benefit you greatly. This is the route I probably will move next year. As for the converter you don’t necessarily have to upgrade it. Again, if you rarely connect to shore power you more than likely will be getting solar charge which will get you to 100%.

I would also track the usage of your AGMs in your Victron app. I wonder if you have defective batteries.

johnfconway · November 2023

Even with the 2-way Isotherm 130 refrigerator, if cabin temperature gets above 90 degrees, it's worth knowing what is going on inside. A bluetooth thermometer inside with readout on phone will change your opening/closing habits. That's a tiny space for a gush of hot air.

While the Isotherm seems like it would be impossible to open during transit, keep duct tape on hand if you're forced to head up any road with a name like "Trans Mountain Road", because tent campers occupied all of the spots in Sunny Vale Campground.

RCB · November 2023

I too am wondering about changing to Lithium as my AGMs are 5 years old. There is probably a few more years in them.

Regarding moving to lithium, my concerns / questions revolve around charging them are:
1. should the existing converter be changed or is adding a dc to dc charger preferable.
2. the tv works at a lower voltage than lithium so getting any charge from the tv is doubtful without a dc to dc charger as I understand
3. if no dc to dc charger then would a shunt be necessary to prevent electrical flow from tv to trailer or vis versa ?
4. if the trailer converter is left in place to partially charge the lithiums could the solar panel be expected to complete the charging ?
thanks

pthomas745 · November 2023

@RCB 4: if your trailer has a Victron solar controller, it can be set up to completely charge a lithium battery. In essence, most owners have installed lithium batteries, and skipped all of the converter swaps, the DC-DC chargers, and simply allow the solar to do the job. The "non-lithium" WFCO in my trailer brings my lithium battery up to 85 percent, so it hardly seemed worth it to spend hundreds of dollars for 15 amp hours, when my solar setup does the job just fine.

If you are talking about a "shunt" as a battery monitor, they aren't "necessary", but they surely are an excellent way to accurately keep track of your battery. Put one on your list.

The "electrical flow from trailer to vehicle" depends on whether or not your vehicle has what is called an "isolation relay" that prevents the trailer from drawing power from the tow vehicle when the tow vehicle ignition is off. Look over this thread and you can find a simple experiment from "Mouseketab" that explains how to find out if your vehicle has one.

https://tab-rv.vanillacommunity.com/discussion/10956/do-you-disconnect-the-electrical-plug-from-your-car-truck-when-stopping-for-an-hour-or-so-to-shop

Charging from a vehicle is a whole subject by itself. Do you know if your vehicle charges your AGM while driving now?

DM159 · November 2023

Just a bit more info to my original post - After reading additional comments and doing more research on my part about LiON usage, I'm thinking our two, 6 volt AGM batteries need to be replaced. This is because of the ALDE over night heating on 12volt above 5000' with low outside temps brings the battery State of Charge much too low and ALDE goes into "limp mode". The batteries recovered once the sun comes up. Loosing ALDE heating at 2am is a bummer. OEM Solar panels on the TAB400 are outstanding at keeping the AGM batteries charged during the day - we even have portable solar panels as additional battery charging on cloudy days. Shore power works great at keeping the AGM batteries at 100%. Extended boondocking and Harvest Host over night stays have shown a "kink in the armor" so to speak.

Marceline · November 2023

DM159 said:

Just a bit more info to my original post - After reading additional comments and doing more research on my part about LiON usage, I'm thinking our two, 6 volt AGM batteries need to be replaced. This is because of the ALDE over night heating on 12volt above 5000' with low outside temps brings the battery State of Charge much too low and ALDE goes into "limp mode". The batteries recovered once the sun comes up. Loosing ALDE heating at 2am is a bummer. OEM Solar panels on the TAB400 are outstanding at keeping the AGM batteries charged during the day - we even have portable solar panels as additional battery charging on cloudy days. Shore power works great at keeping the AGM batteries at 100%. Extended boondocking and Harvest Host over night stays have shown a "kink in the armor" so to speak.

You aren’t using the Alde on propane mode when you don’t have shore power?

DM159 · November 2023

Yes Marceline, we were using propane for the ALDE heating at 3000'. At 5500' with ALDE on propane, it was "gasping" and would not run consistently even with the ALDE control on the "Altitude" setting.

rh5555 · November 2023

The Alde needs a "good" 12V supply to operate the gas valves and circulation pump. We get a "Gas Failure" warning when our batteries get too low and no hot water, let alone cabin heat.

johnfconway · November 2023

DM159 said:

Yes Marceline, we were using propane for the ALDE heating at 3000'. At 5500' with ALDE on propane, it was "gasping" and would not run consistently even with the ALDE control on the "Altitude" setting.

Did you have Alde set for high altitude (if it's set, there is a flashing mountain on screen)? Our Alde heats just fine at just over 10,000. Lowest elevation has been 4500.
Same setting works well in that zone.

DM159 · November 2023

Thanks for the comment rh5555. It is very possible our problem with ALDE at elevation could be the AGM battery had too low of a voltage and causing the "gasping"/no heat. More reason to upgrade to LiFePo4 batteries.

pthomas745 · November 2023

@DM159 What we need (and you need) to fully determine what is going on with your battery are the actual state of charge numbers for your battery. Do you have the Victron app? The Alde does require a minimum of 10.5 volts to actually work. As long as the battery voltage number is above that, the Alde should run on propane just fine. The battery would not prevent the Alde from working until it goes below 10.5V. Below that...it just stops.

In your trailer you have the Alde 3020 HE. The "HE" is the Alde set up with a "High Elevation" mode. You must select that mode in the menu, the Alde does go into that mode automatically. So, have a look at the manual, Page 20 or so, and find the little "High Altitude" mode setting.

So: Do you have the Victron app to get good data about your battery voltage? Were you using the High Altitude Mode while you were camping?

rh5555 · November 2023

That's interesting to know, @pthomas745. Our Alde will not work that low. It gives a "Gas failure" message somewhere above 11V. Maybe we have a weak gas valve that is not operating as it should down to 10.5V.

DM159 · November 2023

Thanks for your post pthomas745. Battery State of Charge when ALDE 3020 was having difficulty was 10.6 as seen on the Victron SmartBVM app. The High Altitude function was selected as we set up camp. When we turned in for the night, the battery was at 12.5 volts. 3 Way fridge was on propane. The ALDE display had the "Low Battery" code when we realized it was getting colder inside.

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To Keep or Not To Keep? AGM

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