Interstate Battery issues

[FlyFishinRVr]

Originally Posted by TheHoff

Again, thanks for your thoughts. I pulled the circuit breaker panel and indeed did finally find the Atkins solar control unit. For future reference, it is located behind the left lower quadrant of the removable panel the circuit breaker box is mounted on, and there is plenty of room to install a new MPPT controller unit on that panel.
There were no fuses either on the positive or negative side of the controller unit as the wires went to their respective terminal bus. One good thing was that I found a very loose wire on the Positive bus bar that I tightened, not related to the issue at hand.
If anyone has any other info, let me know. So far the instillation is working flawlessly. We will see what happens when I get above 10 amps of solar. The Atkins unit is rated for 25 apms, well above my potential solar output of about 20 amps, which realistically not achievable.
I'm just guessing here, but I think since Airstream offers a solar upgrade option , the entire system is already designed for for additional panels of 200 watts output, and, like I did, you just add the panels and hook them up on the roof. I have no way of verifying that except that is working as if that were the case. My Interstate is a 2016 model.

Good stuff. Thanks very much for the update.

I agree, I think our rigs can handle a total of 300W of solar as is, but I still feel the weak link is the Atkinson controller. I'll be testing that theory shortly as I'll be replacing it with a MPPT controller but NOT increasing my solar capacity (yet) and see how the single 100W panel does with a decent controller running the show. My rig gets all day sun where it's parked so it should be a good test to see how this will work. Lew has commented many times that just replacing the solar charge controller will greatly improve the performance of the existing solar, and I expect he will be right....again.

More soon.....

[FlyFishinRVr]

Originally Posted by Zil

Im with Lew. There is no reason for a six volt battery to fail on it's own. They are heavier built than any 12 volt I have come across. And I use four, series/parallel. But, I do like Duracell from East Penn, available at Batteries plus and also Sam's Club.

4 in series/parallel sounds like a great solution. Where did you install them? Also, what Ah rating did you install?

[JayP]

Originally Posted by FlyFishinRVr

4 in series/parallel sounds like a great solution. Where did you install them? Also, what Ah rating did you install?

I was inspired by Boxster and did the 4 battery 6v series/parallel install. I installed two in the same place as the originals and then two in the same place curb side. The original boxes were not large enough so I designed and had made larger boxes of very similar design as the originals but wide enough to hold 2 batteries each.

[FlyFishinRVr]

Originally Posted by JayP

I was inspired by Boxster and did the 4 battery 6v series/parallel install. I installed two in the same place as the originals and then two in the same place curb side. The original boxes were not large enough so I designed and had made larger boxes of very similar design as the originals but wide enough to hold 2 batteries each.

Very nice! That looks like a really good setup.

[Boxster1971]

Originally Posted by JayP

I was inspired by Boxster and did the 4 battery 6v series/parallel install. I installed two in the same place as the originals and then two in the same place curb side. The original boxes were not large enough so I designed and had made larger boxes of very similar design as the originals but wide enough to hold 2 batteries each.

Nice! Now that is a mod that Airstream should adapt to give the Interstates the 440 AH AGM battery pack that would make a more useful camper. Add 300-400 watts of solar and you have a near perfect B-van.

... and I was inspired to mount the AGM batteries under my Interstate, behind the rear wheels, when I first saw that Airstream was putting their batteries there. I considered going with Lithium batteries until I discovered their below freezing limitations. My van is exposed to many months when overnight temps go well below freezing.

[FlyFishinRVr]

Originally Posted by Boxster1971

Nice! Now that is a mod that Airstream should adapt to give the Interstates the 440 AH AGM battery pack that would make a more useful camper. Add 300-400 watts of solar and you have a near perfect B-van.

Are these golf cart batteries similar to other AGM batteries and you only get 50% of their stated Ah out of them before they die?

[amirm]

Originally Posted by Boxster1971

... and I was inspired to mount the AGM batteries under my Interstate, behind the rear wheels, when I first saw that Airstream was putting their batteries there. I considered going with Lithium batteries until I discovered their below freezing limitations. My van is exposed to many months when overnight temps go well below freezing.

If you put the Lithium pack inside, then outside temps don't matter.

[lewster]

Originally Posted by FlyFishinRVr

Are these golf cart batteries similar to other AGM batteries and you only get 50% of their stated Ah out of them before they die?

Golf cart batteries won't 'die' at 50% depth of discharge. That capacity level is used as a benchmark by many battery manufacturers to compare lifespan, which is usually designated by the number of charge cycles you can expect from a battery.

Lifeline has a nice chart in the back of their technical manual (http://lifelinebatteries.com/wp-cont...cal-Manual.pdf) that shows the number of expected charge cycles as a function of the discharge levels (depth of discharge % or DoD). 100% CAPACITY =>12.8VDC @77ºF

For example:
•50% DoD = 1000 cycles (12.15VDC)
Other levels are:
• 10% DoD = 5000 cycles (12.65VDC)
• 20% DoD = 2800 cycles (12.55VDC)
• 70% DoD = 650 cycles (11.83VDC)

100% DOD = 10.5VDC

As you can see, the less you draw a battery down, the longer you can expect it to give you service. This is a good reason to have a properly sized battery bank, as investing in another battery or two (depending on your specific use patters and space availability) will more than pay for itself over the long run by extending the life of your batteries.

Oc course, there are many other factors that effect battery life, but depth of discharge and proper charging with temperature compensation are the 'big two'.

[FlyFishinRVr]

Originally Posted by lewster

Golf cart batteries won't 'die' at 50% depth of discharge. That capacity level is used as a benchmark by many battery manufacturers to compare lifespan, which is usually designated by the number of charge cycles you can expect from a battery.

Thanks Lew.

So, do the golf cart batteries follow a similar curve (i.e. 1000 cycles if taken to 50%) or are they more robust and they can go 2000 cycles, 3000 cycles, whatever if you take them that low?

Just curious really as any battery upgrade I do on my coach will likely be based on new tech (i.e. whatever comes after Lithium), but it might be interesting for folks following this thread to know what to expect from the switch from 12v'ers to 6v'ers.

[Boxster1971]

Originally Posted by amirm

If you put the Lithium pack inside, then outside temps don't matter.

Putting them inside won't help much unless it is a heated space. My van sits in the driveway on a winter day with solar charging and temp around 15degF. It is definitely below freezing inside the van in those conditions unless you add heat. I've also made winter trips to Minnesota when temp was -15degF. Yikes!

If you go to Lithium in cold climate you need to add a heat source to avoid risk of damaging batteries if charged below freezing. This is one of the major limitations of current Electric Vehicles in cold climates. They give up a lot of battery power to keep their Lithium batteries above freezing.

[Boxster1971]

Originally Posted by FlyFishinRVr

Thanks Lew.

So, do the golf cart batteries follow a similar curve (i.e. 1000 cycles if taken to 50%) or are they more robust and they can go 2000 cycles, 3000 cycles, whatever if you take them that low?

Just curious really as any battery upgrade I do on my coach will likely be based on new tech (i.e. whatever comes after Lithium), but it might be interesting for folks following this thread to know what to expect from the switch from 12v'ers to 6v'ers.

Golf cart batteries is a generic term. Most golf cart batteries are just conventional wet cell lead acid batteries designed to take deep discharge abuse as a propulsion battery. Lew and I are talking about robust Lifeline 6V AGM batteries.

All batteries, lead or lithium have a characteristic of longer life if not discharged deeply. Just that lithiums are generally better for deep discharges.

In my case I ran the numbers on comparing different 12V and 6V Lifeline AGM batteries. The Lifeline GPL‑4CT AGM Deep Cycle Battery had the best energy for weight and volume.

[amirm]

Originally Posted by Boxster1971

Putting them inside won't help much unless it is a heated space. My van sits in the driveway on a winter day with solar charging and temp around 15degF. It is definitely below freezing inside the van in those conditions unless you add heat. I've also made winter trips to Minnesota when temp was -15degF. Yikes!

If you go to Lithium in cold climate you need to add a heat source to avoid risk of damaging batteries if charged below freezing. This is one of the major limitations of current Electric Vehicles in cold climates. They give up a lot of battery power to keep their Lithium batteries above freezing.

At the risk of stating the obvious , if you are using the AI, then it is not going to be below zero temps inside. Unless you are a very hardy person.

When not in use, below zero just means not charging them. A BMS enables that. Once you are using it and the cabin warms up, then it can be charged again using the engine, solar, etc.

BTW, manufacturer specs actually allow charging even below zero. It is that that general knowledge says to not do it.

[FlyFishinRVr]

Originally Posted by TheHoff

Again, thanks for your thoughts. I pulled the circuit breaker panel and indeed did finally find the Atkins solar control unit. For future reference, it is located behind the left lower quadrant of the removable panel the circuit breaker box is mounted on, and there is plenty of room to install a new MPPT controller unit on that panel.

There were no fuses either on the positive or negative side of the controller unit as the wires went to their respective terminal bus. One good thing was that I found a very loose wire on the Positive bus bar that I tightened, not related to the issue at hand.

If anyone has any other info, let me know. So far the instillation is working flawlessly. We will see what happens when I get above 10 amps of solar.

I just spent a couple sweaty hours monkeying around under the DS jump seat and did find a fuse in the solar circuit. On my rig the solar bundle (yellow and green) splits with the yellow (solar +) going to the Atkinson controller and the green (solar -) going to a fuse holder with orange leads. The other side of the fuse holder is connected to a stud that is tied to chassis ground. This leads me to believe that at the least there is a fuse on the solar panel so you need to check it if your solar suddenly stops working.

As for space, no way my MPPT controller will fit in the space under that jump seat. I might be able to make room if I move a few things around but instead I'm going to mount it on the outside of the jump seat base facing the rear of the coach. It will fit perfectly, be accessible if it ever needs to be reset, and the wires will easily route through the vent on that side of the seat base. It's not ideal as I'd rather have it totally hidden, but this will get the job done with very little fuss and will only be visible if you're looking for it.

Today was a perfect example of why I'm doing this mod. My house batts were at 12.8v and the chassis batt was at 12.3v and the solar was OFF, even though the sun was shining brightly. Ugh..... [emoji35]

Oh, and FWIW my blue wire on my Atkinson is clipped (I think this sets the controller to turn on when the batteries go below 12.7v vs 12.4v, and mine turns on just below 12.7v so this seems to match what I'm seeing) and there is no temp probe attached so I have no temp compensation. [emoji53]

[lewster]

Originally Posted by FlyFishinRVr

I just spent a couple sweaty hours monkeying around under the DS jump seat and did find a fuse in the solar circuit. On my rig the solar bundle (yellow and green) splits with the yellow (solar +) going to the Atkinson controller and the green (solar -) going to a fuse holder with orange leads. The other side of the fuse holder is connected to a stud that is tied to chassis ground. This leads me to believe that at the least there is a fuse on the solar panel so you need to check it if your solar suddenly stops working.

As for space, no way my MPPT controller will fit in the space under that jump seat. I might be able to make room if I move a few things around but instead I'm going to mount it on the outside of the jump seat base facing the rear of the coach. It will fit perfectly, be accessible if it ever needs to be reset, and the wires will easily route through the vent on that side of the seat base. It's not ideal as I'd rather have it totally hidden, but this will get the job done with very little fuss and will only be visible if you're looking for it.

Today was a perfect example of why I'm doing this mod. My house batts were at 12.8v and the chassis batt was at 12.3v and the solar was OFF, even though the sun was shining brightly. Ugh..... [emoji35]

Oh, and FWIW my blue wire on my Atkinson is clipped (I think this sets the controller to turn on when the batteries go below 12.7v vs 12.4v, and mine turns on just below 12.7v so this seems to match what I'm seeing) and there is no temp probe attached so I have no temp compensation. [emoji53]

Time for a Victron Blue Solar controller upgrade?

[FlyFishinRVr]

Originally Posted by FlyFishinRVr

Oh, and FWIW my blue wire on my Atkinson is clipped (I think this sets the controller to turn on when the batteries go below 12.7v vs 12.4v, and mine turns on just below 12.7v so this seems to match what I'm seeing) and there is no temp probe attached so I have no temp compensation. [emoji53]

Two corrections:

I just reviewed the specs of the Atkinson and it has built in temp compensation so no external temp probe is used, but given the controller is mounted inside the coach and the batteries are outside and under the rig, it's basically useless.

Cutting the blue wire is how they set it for sealed batteries and that supposedly sets the turn on voltage to 12.4v. This is really odd because I've watched mine turn on at 12.6 - 12.7v yet my blue wire is clipped. Not sure what's up with that but I thought I'd mention it. Soon I won't care....[emoji57]

[Njg]

I'm going for a setup as described by TheHoff earlier in this thread. What is the proper way to secure the additional 2 100w solar panels (I am installing behind the roof AC) to the roof? Do I use z brackets? Screws with the self leveling adhesive, tape of some kind?

[lewster]

Originally Posted by Njg

I'm going for a setup as described by TheHoff earlier in this thread. What is the proper way to secure the additional 2 100w solar panels (I am installing behind the roof AC) to the roof? Do I use z brackets? Screws with the self leveling adhesive, tape of some kind?

I probably have several hundred panels mounted on Airstream Interstate vans over the last 10 years....all with 3M VHB 4901 tape and a covering of SikaFlex 221. NO SCREWS...... NO HOLES!!!

Haven't lost a panel yet!!

As always...........your mileage may vary!!

[TheHoff]

Two things to report.
I did use screws to mount my two new solar panels. I should have used tape. They are very light and hidden behind the air conditioner unit aerodynamically, so the experience of others should be supersede mine in the mounting question.
After one month, I couldn't be happier with my upgrade solar instillation. With the main disc off, my batteries never fall below 90 %, even on rainy days or when parked in partial shade. When boondocking, I can run the radio, refrig, lights, vent fans and overnite, the lowest battery charge I have seen has been 60% . After 2 hours of sun and 15 minutes of generator time for an espresso, I'm back to 90-100% and then 100 % all day.
And one more thing, I contacted Airstream about an in line 15 amp fuse noted by another forum contributor, and they said starting with 2018, the fuse is no longer installed. Workers on the line said the fuse may or may not be there in my 2016 model. If it is there, it would be on the red wire near the battery bus near the inverter under the DS rear seat. My unit does not have one that I can find anywhere. I have recorded 15.5 amps of solar generation so far with my instillation. I am still using the Atkins controller and display and have been satisfied with it's function so far.

[Njg]

Thanks for that information! My plan was to use the VHB tape but then screw through that and cover the whole base with dicor. How long were the screws you used?

Also, lew, if I am sticking with the Airstream supplied lifelines for now, what settings on the victron MPPT to you recommend? One of the canned settings or custom settings. I have the Bluetooth attachment so can readily change them.

[FlyFishinRVr]

Originally Posted by Njg

Thanks for that information! My plan was to use the VHB tape but then screw through that and cover the whole base with dicor. How long were the screws you used?

Also, lew, if I am sticking with the Airstream supplied lifelines for now, what settings on the victron MPPT to you recommend? One of the canned settings or custom settings. I have the Bluetooth attachment so can readily change them.

I just set my MPPT controller to match the Lifeline battery specs, found here:
http://lifelinebatteries.com/wp-cont...cal-Manual.pdf

And you really should follow Lew's recommendation to NOT use screws. Use SikaFlex and tape and you'll be fine, and you'll never have to worry about leaking.