What is low battery

[RedRoadTtrek]

Originally Posted by booster

I must be missing something. The 400ah setup for the Zion is Lithium from all I have heard. The AGM is 182ah, although Roadtrek is inclined to call it a 400 amp battery in advertising.

What kind of power use are seeing per day? Do you have a battery monitor on it to see what you are using and what the actual state of charge is. If you don't, that would be a very good addition. Hardly anyone would normally need 1000ah of battery to be off grid a lot. We have 440ah with a compressor frig and could go 5+ days on just batteries with no engine charging or solar input.

Also remember that the high idle will give you some extra output, but like nearly all of the engine charging systems, you will not get anywhere near the rated output over any real length of time. The most you can realistically expect would be about 165 amps average output from the engine generator setup if it is a standalone. 1500 rpm is also very irritating to be around for longer term charging, but that is another discussion.

Oh, and I also heard from other Zion owners that the Lithium Ion option was nothing but problems. RT has since stopped offering it? The word "on the street" was stay away from LiOn, and stay with AGM's. That way you can not have to worry about overheating of batteries at certain charge rates, and everything works with everything. And yes, you have to run for 3-4 hours (or be plugged into 110V for 3-4 hours) to get a good "soaking" charge in the battery or, in our case, batteries. Short of that, my stopgap solution when camped is to put a short carefully-calibrated length stick between the dash and the gas pedal to get the idle up to about 1500 RPM, and let her run for about 30-45 minutes to bring some charge back into the batteries. Peter also said to keep the inverter off, except when you actually need it for the microwave or TV (and DON'T run the Dometic A/C with out the engine running above idle). Also, when you are storing, turn the power off. The solar panel will keep the batteries up, even with modest sun. If you don't have good sun, try to plug it in. But keep the power switch turned off when you are storing the Zion, and never turn the inverter on except when you actually need it (just having the inverter on without it doing anything creates a small drain on the battery).

[RedRoadTtrek]

Originally Posted by markopolo

You'll end up with only a bit more than half the 1000AH you anticipate.

Northstar AGM 400 = 182 Ah
https://www.northstarbattery.com/pro...gm-400?p=51228

Folks confuse the model # AGM 400 with capacity 182AH.

TWO Northstar AGM 400's plus 200AH Lifeline batteries = 182AH + 182AH + 200AH = 564AH total capacity - not even close to 1000AH.

Ooops, I dug out the specs on the AGM400, and you are right! I stand corrected. So that means we will have about 560 AH. The bottom line is that we went a long way to correcting the low-voltage problem when we added the Lifelines for 200AH+ -- enough that we are fairly confident that the second AGM400 will make the Zion a really usable boondocker, allowing us to go at least 2-3 days without sun, external power, or engine-starting, assuming we are careful with power usage. In full daily sun, I expect that we could be in camp in perpetuity without external charge or engine starting? Hope springs eternal from the human breast! So, other than the undersized battery capacity, the Zion is a great product. All the other issues are minor fixes, and we can live with that. By the way, we added three Supersprings products which helped the handling and ride immensely: Supersprings and Sumo Springs in the rear, and SuperSway Stops in the front coils. Highly recommended!

[wincrasher]

Nonsense. Lithium batteries solve alot of problems and really only require minimal care and monitoring. Roadtrek's problems are of their own creation with thier poor bms and voltrek implementation. Mine have been trouble free and reliable and gives you power freedom where before I had lots of anxiety of running my batteries dead.

[booster]

Originally Posted by RedRoadTtrek

The 2016 Zion uses the Northstar AGM400, which is an excellent battery. Peter Lange at RT, just before he retired, was pretty frank with me about the problem: Even with the Northstar battery, the capacity is not enough. He suggested adding batteries. I have since been able to add 2 Lifeline AGM's to bring it up another 200AH. This was a somewhat complicated installation to accomplish safely and securely in the only 2 remaining under-carriage open areas. Alas, this improvement turned out to be barely enough for a couple of days of disconnected boondocking with modest sun on the solar panel. We have decided to add another Northstar AGM400, which will have to go topside, as there is no more room underside. This will bring the total capacity to over 1000AH, and I think this will "solve" the problem. Before he departed for his retirement, Peter also said that, running below 12.0V risks damaging the battery. The hard news is that ya gotta get more AH...a LOT more, to make the Zion work right -- unless you want to be awakened (or have your camping neighbors) awakened at all hours of the night with the Volt-Start cranking up the engine (then having no good way to "up" the idle so that it really puts some power back into the battery). And, it turns out, that we will be able to ramp up to 1000+AH for less than the cost of buying and installing the obnoxious Volt-Start. But remember, I'm skilled, and can do a professional and responsible job of it without paying zillions to some inexperienced and under-skilled mechanic at the RV shop!

Redroadtrek posted while I was writing this, so some of it doesn't apply now.

The Northstar AGM400 is not a 400 amp hour battery, it is 182 amp hours, so you have 382ah currently and if you are only going to 50% (more on that later) that is 191ah. Add to that if you are short charging, which is highly likely, you will only get to about 80% full (it takes up to 10 hours to get totally full), so you have only 30% usable capacity from your existing batteries, or 115ah, which is about what it will take, with a little sun, to run two days.

Love Peter to death, but more current information (which is available on this site), is indicating that going below 50% state of charge on AGM batteries, or wet cells even, is not the death threat we all have been led to believe. In reality, going from 50% down, to 80% down will only shorten the life of the battery by about 10%, if you use the total amp hours in and out which is what counts. The charts show number of cycles, which doesn't make for a decent comparison as you recharge less often if you go deeper. In your case, with the likely short charging, you would double your battery capacity by going to 20% instead of 50%, which would give you more like 4 days off grid. I will get links on here in a bit so you can see the logic behind going deeper, with the data we have found. This is a controversial issue to many people, but the data is really pretty clear, at least to some of us

IMO, you may be shortening battery life quite a bit by the mix of battery chemistries, manufacturers, and capacities. I think I would get some voltmeters on the them to see if they are evenly charging and discharging. The short charging, if you have it, will make this issue worse also.

If you have short charging, which will shorten battery life substantially if not addressed, you need to get a completely full charge every 7-10 charge cycles. The best way to determine the full charge is with a battery monitor that checks the final amps and volts to determine true 100%. If you don't get full regularly, the capacity will walk down over time.

In summary, you now have 382ah capacity, or which you are likely only using 115ah. You can instantly double that usable capacity by going to 20% state of charge, and will incur only a tiny penalty in battery life, which is likely less penalty than you are getting from short charging and mixed batteries. If you do add another AGM400 you would have 564ah of capacity (not 1000ah) of which you get 169ah usable at 50% discharge, and 338 ah at 20% state of charge limit. That would be 3 times the capacity you are getting now, I think. Of course, you will be hauling around near 400# of batteries and using up a lot of space with them.

We have a very similar setup, and likely similar usage. 440ah of Lifeline batteries, 300 watts solar, compressor frig. Normal use of 30-60ah per day depending on conditions. With no sun, we can go about 5 days if we are full when we start, closer to 3 days if only at 80% from a short charge. If we have decent sun we can go forever off grid. All of our charging is set up to allow us to get totally to 100% charged, if we have the time to do it, and we make sure we get there about every 7 charge cycles. 382ah of battery capacity is very large compared to what most people have, and should let you stay off grid at least 4 days, and more based on solar output.

Personally, if I were in your current position, I would get some monitoring on the mixed batteries to see if they are playing well together, and then start going to 20% state of charge instead of 50% (assuming you can accurately measure the state of charge with a good battery monitor, which can be tough with batteries in various locations, voltage only is not a good indicator of state of charge) and see how it goes for you. I would also confirm how full you are getting after various charge cycles to determine if you are actually short charging most of the time and if you ever do get totally to 100%, which also requires a properly set up battery monitor.

IMO, you shouldn't really need the Voltstart, as you have enough capacity to cover usage for long periods. This give you the option of manually starting the engine at convenient, and non intrusive to other campers, times. Even at idle, you should be able to recover one day's use in about 30 minutes, and if driving about 20 minutes which is about what it takes to go the dump station or trailhead, many of us have found.

[booster]

Here is a link to the latest discussion on the 50% rule. Be sure to click the link to the previous thread, which is in the second post, as there is more information there, although a lot of it has also been copied into this one.

http://www.classbforum.com/forums/f2...imit-5595.html

spec page on the AGM400
SMS-AGM 400

NorthStar automotive batteries excel at providing both high reserve capacity and cranking amps, perfect for performance and start-stop technology applications. Capacity up to 182 Ah

[Boxster1971]

Originally Posted by wincrasher

Nonsense. Lithium batteries solve alot of problems and really only require minimal care and monitoring. Roadtrek's problems are of their own creation with thier poor bms and voltrek implementation. Mine have been trouble free and reliable and gives you power freedom where before I had lots of anxiety of running my batteries dead.

I agree. Lithium batteries are perfect for B-vans. The problem is Roadtrek's implementation.

- - Mike
2012 Sprinter 3500 Extended converted B-Van by Airstream

[booster]

Originally Posted by Boxster1971

I agree. Lithium batteries are perfect for B-vans. The problem is Roadtrek's implementation.

- - Mike
2012 Sprinter 3500 Extended converted B-Van by Airstream

I would totally agree with Roadtrek part, for sure, the "perfect" would be a bit of a stretch for me because of the cold weather storage and charging issues which would apply to some of us.

[Boxster1971]

Originally Posted by booster

I would totally agree with Roadtrek part, for sure, the "perfect" would be a bit of a stretch for me because of the cold weather storage and charging issues which would apply to some of us.

I also went with AGMs, 400AH Lifeline 6Vs, for the same reason. As a DIY project adding the complexity of multiple battery types and cold weather charging were more than I wanted to deal with. But a properly designed Lithium system like Advanced RV installs is perfection in my book.


- - Mike
2012 Sprinter 3500 Extended converted B-Van by Airstream

[BBQ]

Originally Posted by RedRoadTtrek

The 2016 Zion uses the Northstar AGM400, which is an excellent battery. Peter Lange at RT, just before he retired, was pretty frank with me about the problem: Even with the Northstar battery, the capacity is not enough. He suggested adding batteries. I have since been able to add 2 Lifeline AGM's to bring it up another 200AH. This was a somewhat complicated installation to accomplish safely and securely in the only 2 remaining under-carriage open areas. Alas, this improvement turned out to be barely enough for a couple of days of disconnected boondocking with modest sun on the solar panel. We have decided to add another Northstar AGM400, which will have to go topside, as there is no more room underside. This will bring the total capacity to over 1000AH, and I think this will "solve" the problem. Before he departed for his retirement, Peter also said that, running below 12.0V risks damaging the battery. The hard news is that ya gotta get more AH...a LOT more, to make the Zion work right -- unless you want to be awakened (or have your camping neighbors) awakened at all hours of the night with the Volt-Start cranking up the engine (then having no good way to "up" the idle so that it really puts some power back into the battery). And, it turns out, that we will be able to ramp up to 1000+AH for less than the cost of buying and installing the obnoxious Volt-Start. But remember, I'm skilled, and can do a professional and responsible job of it without paying zillions to some inexperienced and under-skilled mechanic at the RV shop!

*smh*

But... what appliances you are using that require you have need soooo much AH?

[booster]

Originally Posted by RedRoadTtrek

That way you can not have to worry about overheating of batteries at certain charge rates, and everything works with everything. And yes, you have to run for 3-4 hours (or be plugged into 110V for 3-4 hours) to get a good "soaking" charge in the battery or, in our case, batteries.

Can't speak for the Northstar, but the Lifelines will start to get too hot at about .4C so 40 amps per 100ah of capacity. We have tested this repeatedly and it is very consistent for long charges. If you are only doing a fast recovery charge off big alternators (we can do a full 280 amps (.64C) continuous) you are good for 20-30 minutes before you have to back off the amps. You won't overheat lithium from fast charging as nobody has enough capacity to provide as many amps as it would take IMO.

I think you will find that 3-4 hours is substantially short for a "soak" (absorption stage) time to get the batteries full. Our Lifelines take longer than that to go from 80%-100%. A full charge from 20% state of charge will take somewhere in the 10 hour range for our Lifelines, with the 100 amp Magnum shore charger. The hard part is finding a charger that will stay in absorption stage long enough to get the batteries to 100%. Most run on timers, or a very conservative and inaccurate amp check to go to float stage, and rarely will get you full and also prevent overcharging. As mentioned, if you don't have a battery monitor, you will never know if the batteries are at 100%, as even resting voltage will not tell you.

The specs for the Lifelines say that to be fully charged, the amps to the batteries should be .5%C or 1/2 amp per 100ah of capacity, so 1 amp for your setup. This amperage also has to be at absorption voltage (normally around 14.3/14.4v, temp corrected) to be correct. Checking the amps at float voltage won't tell you much unless you know what float amps will be on the 100% full batteries, and you would have to test it to determine what the amps are. In our case, 440ah of full batteries only take 1/10 amp at float. If the charger goes to float before the batteries are full, you won't ever get full properly. The amps will level off, after many days on float, but it will not be as good as getting there in absorption.

The Northstar specs, IIRC, call out even lower amps to be considered full at .1%C or 1/10 amp per 100ah of capacity, at absorption voltage.

This difference is one of the reasons I would be concerned about the battery mismatch that you have.

[Bud]

Hi Booster,

If the volt meter says 12.9 volts, seldom 13.0 with the Battery Tender hooked up, are my group 27 marine batteries full?

Thanks.

Bud

[booster]

Originally Posted by Bud

Hi Booster,

If the volt meter says 12.9 volts, seldom 13.0 with the Battery Tender hooked up, are my group 27 marine batteries full?

Thanks.

Bud

Very hard to tell, and probably would be at least partly determined by how they were charged before the tender went on.

If they are wet cells, you would be able to check the specific gravity of the electrolyte and get a good state of charge reading.

You can get an approximate state of charge reading by disconnecting the Tender and letting the batteries sit a couple of days to see the true resting, no surface charge voltage. Depending on the style they will be 12.6-12.9 for a full battery from what I have seen, but it is not all that accurate.

To tell for sure on AGM batteries, you need to put on a higher capacity charger than the Tender and have it running at the absorption stage voltage. You would then see how many amps the batteries were taking with an accurate ammeter. Total PITA to be sure, to do it that way, but I don't know any other accurate way to do it.

[booster]

Originally Posted by Boxster1971

I also went with AGMs, 400AH Lifeline 6Vs, for the same reason. As a DIY project adding the complexity of multiple battery types and cold weather charging were more than I wanted to deal with. But a properly designed Lithium system like Advanced RV installs is perfection in my book.


- - Mike
2012 Sprinter 3500 Extended converted B-Van by Airstream

Advanced certainly is close, but even davydd got to the point he had to make sure his van stayed over the -4*F where they say you get permanent damage even just sitting, so he couldn't just put it on a no power storage lot.

[Boxster1971]

Originally Posted by booster

Advanced certainly is close, but even davydd got to the point he had to make sure his van stayed over the -4*F where they say you get permanent damage even just sitting, so he couldn't just put it on a no power storage lot.

Good point. I forgot about those frozen Minnesota winters I grew up with. [emoji1]

During my last trip to Minnesota in February a few years back I was starting my van everyday at -15degF. I was glad to have AGM batteries. Here in Maryland we don't see much below zero, conditions thank goodness.

Just left Minnesota about a week ago and traveled home via the Michigan Upper Peninsula. I was hoping for some cool weather but it was very hot. During our stay on Mackinac Island they experienced the hottest day of the year at nearly 90degF. Drove home yesterday and it was in the 90s all day in Michigan, Ohio Pennsylvania and Maryland. Too hot for my taste.


- - Mike
2012 Sprinter 3500 Extended converted B-Van by Airstream

[RedRoadTtrek]

The owners we talked to certainly inferred that there was some poor engineering and testing on the part of RT, but directly blamed in on the combination of Lithium Ion and AGM and trying to get them to work in one system. I don't know where the real issues lie, but they certainly had some sad tales of woe about the mixture!

[booster]

Originally Posted by RedRoadTtrek

The owners we talked to certainly inferred that there was some poor engineering and testing on the part of RT, but directly blamed in on the combination of Lithium Ion and AGM and trying to get them to work in one system. I don't know where the real issues lie, but they certainly had some sad tales of woe about the mixture!

I don't think that they were wrong in their assessment of the quality of the Roadtrek lithium design, as there do seem to be lots of issues and total lack of consistency with some working and some not. They all have very high parasitic drain, it appears.

If I were to buy a Roadtrek, I would get AGM, but I would certainly take a good look at what components they had in the charging and power distribution and likely improve them, as their AGM setups are not high end at all for components, IMO. And of course, install a battery monitor system first thing, so I could tell what was going on.

[RedRoadTtrek]

Does anyone have a recommendation on battery monitoring systems, and installation on the Roadtrek Zion? Where and how did you mount the meter/switch, and shunt? What brand did you select?

[GeorgeRa]

Originally Posted by RedRoadTtrek

Does anyone have a recommendation on battery monitoring systems, and installation on the Roadtrek Zion? Where and how did you mount the meter/switch, and shunt? What brand did you select?

Victron; taking the market by storm, - https://www.victronenergy.com/battery-monitors/bmv-700

Xantrex; next generation of the original Link 10
Battery Chargers | LinkLITE Battery Monitor | Xantrex
Battery Chargers | LinkPRO Battery Monitor | Xantrex

Bluesea; newest and best, I love the OLED display, high contrast and dimming
https://www.bluesea.com/products/1830/M2_DC_SoC_Monitor

Trimetric; stuck in the last Century
TriMetric Model Descriptions - Bogart Engineering

There are also dedicated units which work with some inverter/chargers like for example Magnum.

[booster]

I just took a look a the monitors George listed, as I hadn't looked at a couple of them since they were updated or new.

The Victron does look very nice, for sure, and the others all have decent histories with users.

I didn't dig deep enough into the instructions to make certain that they all calculate a full battery by looking at current and amps, but it is likely they do, as all of these appear to be amp hour counting units.

I was happily surprised to see more of the units having relay contacts to control external things, but then disappointed that the setable relay triggers didn't include triggering based on full battery conditions, which would be very nice for engine charging setups.

My guess is that any of them would do the job well, so perhaps a reading of the operating instructions for each would give a you an idea which one you would find the most convenient to use would be.

The monitor readout can mount anywhere you want it, and can get the cable to easily, and the shunt mounts as close to the batteries as you can get it, in the negative battery cable.

As was mentioned, you can also get a monitor built in to the remotes for inverter/chargers and solar controllers, so if an upgrade of either of those is in the near future plans (OEM use models of both tend to not be great by any stretch) that could be a very good option. We wound up with two monitors as both our Blue Sky solar and Magnum charger have them built in because they both base their charging off a current shunt for accuracy.

[BBQ]

Originally Posted by RedRoadTtrek

Does anyone have a recommendation on battery monitoring systems, and installation on the Roadtrek Zion? Where and how did you mount the meter/switch, and shunt? What brand did you select?

AGM or ecotrek?