Upgrade to LI Batteries and Solar- 2017 Forester 2401S MBS

[Bertha17]

Hello Forum,
My wife Hope and I have owned Bertha since 2017. We have taken four cross country trips of 60 days or longer, travelled the northeast, mid Atlantic and southeast, along with shorter, local trips. We prefer to camp in National Parks, National Forests and State Parks as we take in the scenic beauty and cultural sites of North America. We like to boondock and stay at Harvest Hosts.

After 57,000 miles would like to upgrade Group 27 batteries to Lithium Batteries and add solar panels to the roof.

I am a DIY guy who has used the forum (without joining), for maintenance and problem solving advice. I am impressed with the depth and breadth of knowledge shared, as well as the friendly exchange of information and experiences. Hopefully, without creating a start from scratch project, some savvy members might be able to point me to some threads and/or resources so that I can properly understand, scope, spec, procure and install needed components.

Thanks in advance. And, enjoy the journey!

[SeaDog]

Place to start is the forum library there tons of articles on solar and lithium batteries.

[Aussieguy]

are you planning to do a lot more off grid?
DID ..... you use a generator a lot while boondocking?
do you expect/want to run more power hungry stuff while off grid ?
(air conditioning )

If NO to the above... stick to what you know works for you

OR keep your upgrade to a minimum example:
some solar panels (400-600w)
keep existing battery system or a small Lifepo4 (200ah) bank ?


KEEP IT SIMPLE. and have plans for rainy days

--------------------------------------------------
If you want to go all out and create a system that allows almost unlimited off grid.

Battery size....
you need to work out what power consumption you are likely to use in a day.
if you are never far away from shorepower ........... double the estimate
if you are spending a lot of time off grid ................. triple your estimate.


Lithium is good choice IF you have limited time to charge
or... if you increase your usage and need to put back a lot more charge than previously.

Lead acid if you can hookup to shorepower a lot.


once you know your consumption estimates you can figure out the number of solar panels you need. this is also determined by where you will be going to.


forest .. lots of shade = more panels maybe a suitcase.

OR desert plenty of sun.




DIY person...
before buying batteries check out if you want to build a battery
can reduce costs and fit into smaller spaces than buying pre-made batteries.


https://www.google.com/search?client...battery+for+RV

[TitanMike]

Originally Posted by Bertha17

Hello Forum,

My wife Hope and I have owned Bertha since 2017. We have taken four cross country trips of 60 days or longer, travelled the northeast, mid Atlantic and southeast, along with shorter, local trips. We prefer to camp in National Parks, National Forests and State Parks as we take in the scenic beauty and cultural sites of North America. We like to boondock and stay at Harvest Hosts.



After 57,000 miles would like to upgrade Group 27 batteries to Lithium Batteries and add solar panels to the roof.



I am a DIY guy who has used the forum (without joining), for maintenance and problem solving advice. I am impressed with the depth and breadth of knowledge shared, as well as the friendly exchange of information and experiences. Hopefully, without creating a start from scratch project, some savvy members might be able to point me to some threads and/or resources so that I can properly understand, scope, spec, procure and install needed components.



Thanks in advance. And, enjoy the journey!

The very first step I would recommend before changing/upgrading anything would be to log power use from existing batteries on a couple boondocking trips. When you've determined your daily appetite for power (in amp hours) you can then move to next steps like size of battery bank, how much solar, etc.

Lithium is nice but be aware that one 100ah battery will essentially replace two 100 ah lead acid batteries and require about half (or less) charging time than lead cousins.

If you don't already have one I'd start now with a shunt type battery monitor and if you want to be able to monitor your new charging system start with a Victron Smart Shunt or BMV-712. Extra $$ but well spent. Other Victron devices like Converter/Charger, Smart Solar Controller, and DC-DC charger for charging from Alternator while under way, can all be monitored from a single app on your phone.

In short, make sure you know what you need first based on current usage, plus some margin for anticipated growth, so you build enough in your new system but don't spent $$$ on overbuilding.

Sent from my SM-N950U1 using Forest River Forums mobile app

[Bertha17]

Thanks for the specific replies and pointing me to resources in the forum. I have a better understanding of the basics and am closer to being able to identify what our wattage and amp hours requirements are and some options for components we may need.

Reading The 12v Side of Life in the library helped to clarify and quantify what I knew generally. I must work on the math and perhaps uncover an electrical component problem and/or phantom load with my current system.

Current System:

2- Group 27 (90AH) Batteries purchased at O'Rilley in August 2020 (replaced the original Group 24 batteries March 2017). It seems like I did not get the expected longevity for either set.

Progressive Dynamics PD4000 Series Power Control Center

Power Dynamics PD5100 Automatic Transfer Switch

Usage:

We enjoy being off grid and boondocking from overnight to three nights without using very much power hungry stuff. We used the generator sparingly (less than 25 hours per year including exercising .5 hours every two months). Being new to RVing, I did not pay as much attention to the factory installed digital voltage reading on our control panel as I should have with the first set of batteries. Accordingly, we went below 50% state of charge numerous times. We did run the engine or generator before pulling the slide in after tripping the circuit breaker multiple times. Over the winter, Bertha was plugged in in our dirveway. With the second set of batteries I was more diligent in monitoring the electrolyte level and state of charge, recharging the system before it reached 50%, with few exceptions. We used the generator more (30 hours per year exercising monthly). The voltage still seems to drop rapidly with relatively few items drawing wattage. Over the past two years we have had keep her at a storage facility without power. I start her and run the generator monthly. Currently, both batteries will not hold a charge for very long. I tested them and they need to be replaced.

Possible contributing problems:

Not enough time running the generator or driving to adequately recharge between boondocking/hiking before plugging into shore power. For about a year we have had some blinking LED house lights when on battery power. Initially, only one, now more than one. But never all of them. Our water pump seems to briefly cycle on and off without any taps opened. I have checked for leaks and have not found any. Continuing issue with pulling the slide out in.

Working Upgrade Plan:

We want to be able to be off grid more and be more comfortable that our new system will sustain us. I will do the math exercise. But, we do not expect to run AC or other high wattage appliances.

New Batteries- Lithium, perhaps 6V. Shorter recharge time and ability to discharge below 50%.

New Power Center/Converter- I believe we will have to upgrade the Power Control Center for Lithium

Roof mounted Solar Panels/Controller- Ability to maintain charge while driving, Boondocking/at Harvest Hosts and during Winter storage. We have the Zamp connection. But don't like the idea of portable ones only being able to be used when parked and consuming storage space.

Battery Monitor with panel inside coach

DC-DC charger- (I thought we had this functionality)

Inverter- Seems like adding this capability makes sense if the incremental cost is not too much.

Thanks for your help so far. I would greatly appreciate additional insight on the Upgrade Plan and trouble shooting Possible Contributing Problems.

Enjoy the Journey,

[Larry-NC]

Originally Posted by Bertha17

Our water pump seems to briefly cycle on and off without any taps opened. I have checked for leaks and have not found any.

The likely cause is the check valve (one-way valve) in the pump itself. It pumps up static pressure within the piping, and then when the pump stops, the pressure within the piping causes water to seep backwards through the pump to the fresh water tank.

With this problem, if you were to hook up to city water for a while, you would see the water level in the tank rise and eventually overflow.

Sometimes this problem can be cleared by flushing water through the valve with the pump, with no back pressure, but you've been doing that.

Some people take the pump apart and clean the valve.

Some people add an additional check valve to the pump output. This one would work, along with an additional 1/2" coupler.

Let us know which option you pick.

[wharfrat48]

All good suggestions with the most important being figure out your energy needs. Not sure what brand (type) of batteries you have (and had), but I'd guess they were not true deep cycle and more likely RV "dual use" batteries. If so, that is probably the biggest reason why they did not last very long. We boondock almost exclusively and did fine for over 15 years using true deep cycle 6V batteries (replacing every 5+ years or so) and 200-300W of solar. Our energy usage was pretty low and we camped for up to a week with no issues (as long as it wasn't cloudy everyday). Our energy usage has changed (granddaughter camping with us) so when it was time to change out our LA batteries, we upgraded to lithium and am quite happy with the upgrade. With 200 amp/hr of capacity, we have never been below 40%. Do your homework and you will be fine.

[Bertha17]

I have used the suggestions above and expanded my research to come up with a working plan to perform the upgrade.

Our batteries are dead, we do not have a BMS to get accurate readings of power consumption by appliance/system and we are not taking any trips without buying new batteries. Accordingly, I have attempted to calculate our estimated watt hours per day to consumption to right size the system required and plan to procure and install it before we take our first trip.

I continue to appreciate any input, guidance and references to improve my assumptions, decisions and to avoid mistakes.

I reviewed available manuals, looked at the specification labels and researched on line to attempt to calculate total watt hours/day and came up with Essential 1803Wh/day, including Optional items- 1956 Wh/day. However, there are problems in three categories (Missing, Future, Questionable calculations)

1) Missing: Essential- Kwikee Steps 888, Slide out (previously noted frequent tripping resettable fuse issue), Quadra Bigfoot Stabilizers, Awning, Propane Generator, Arctic Pac tank heaters, Dometic Thermostat, Indoor speakers (4), Outdoor speakers (2), Optional- Furion LED TVs (2)

2) Future (New) Items: Solar Charge Controller(s), DC-DC charger, Inverter Charger, BMS, BMS monitor, any AC appliances (e.g. crock pot, blender, coffee pot)

3) Questionable Calculations (high usage and not in synch with internet research Wh):
Suburban Furnace 12V*7A= 84W/hr * 6hrs= 504 W/day
Atwood 6 gal GC6AA-10 water heater 12V*12A= 144W/hr * 2 hrs= 288 W/day
Dometic 2652 6 cuft, DM2652RBX Refrigerator 12V*1.9A= 22.8W/hr * 12 hrs= 273.6 W/day
Maxxair Fan 12V*5A= 60W/hr * 4hrs= 240Wh/day

Using this data (subject to input and correction), and after reading William Prowse's book and reviewing online sources from manufacturers, electrical suppliers, bloggers; it appears that we are on the high side of "normal" configuration a 25ft Class C motorhome. I was surprised by this. But, it all adds up. And, I would rather over build than find out we are unable to boondock for 3 days with an upgraded system. Additionally, we have an on board Onan 3600 W Propane Generator which we could use to charge our battery bank.

Many of the forums and websites for our type of RV featured systems with less than 400 Watts of solar panels with 200Ah Battery Banks. I called two Renogy and they recommended such a system. I called Battleborn and they recommended a 660 Watts of solar panels and a single 270 Ah Battery. I feel that we should be around 600 Watts.

So, I am currently working towards proceeding with the following system:
Battleborn 270Ah 12V LiFePO4 Battery (non heated)- Issues: Large foot print. Too big to fit in current battery box in middle step of entry way. Where else can it be installed? Must it be inside the coach? Or, can it be in an exterior storage compartment? Under the bed was suggested. But this is a small area and relatively far from the current electrical equipment. Some people placed batteries under passenger seat. This seems too small and not readily accessible.
3- Newpowa 220W 12V Monocrystalline solar panels- Issues: Total area available is limited and broken up by objects. Limited pathways to walk around for maintenance. It makes sense to get the most wattage per foot prints available. Three of these panels should fit. They weigh 26 lbs a piece. I do not think this allows much room for future expansion. Plan on mounting on a crowned Fiberglas/foam/luan/tubular aluminum roof by securing with stainless steel screws to tubular aluminum with z braces where possible. Read that panels should be installed in pairs. Parallel or in series? We like to camp in forested areas. The roof is small. Would partial shade be an issue? Stationary or able to tilt? Want efficiency. But do not think going up on the small, obstructed roof on a regular basis is worth the tradeoff and safety risk. Plus, would they be as secure in transit with moveable parts. Is wire entry through Refrigerator vent possible? Or, is it better to make a hole and use a solar entry gland?
Victron SmartSolar MPPT 100/50 Charge Controller- Issues: Is this capable of handling the max solar current produced? Does it leave any room for expansion?
Victron MultiPlus C 12/2000/80-50 120V Inverter Charger- This is a rather large piece of equipment and I am struggling to determine where I can put it where it is close to the battery and other components, ventilated and accessible. Room for expansion? Unclear what additional wiring I must do to change this out with my Power Dynamics PD4060K Converter Charges to gain the AC capability on battery
Victron Orion-Tr Smart 12/12-30A (360W) Isolated DC-DC Charger- I cannot find out if this compatible with my 2016 Mercedes diesel 3500 alternator.
Lynx Distributor-
Battery Monitor BMV-712 BLACK-
Additional Wiring, Fuses and Connectors- What sources are recommended to ensure I obtain all the required items with proper specifications and compatibility for this project?
Thanks in advance for your help

[Bertha17]

Sorry for the length of my previous post requesting input on our Solar/Lithium Upgrade. No feedback so far. So, perhaps just too much to read. Assuming that I will get past my reality check questions on Watt hour consumption/discrepancies and figure out the installation nuances, I hope that you might provide some feedback.

1) Does the Recommended System (for 2496 Wh/day) 1x 270Ah LiFePO4 and 3x 220W panels, seem reasonable and right sized? I calculated our Essential items to be 1803 Wh. Including Optional items, I came up with 1956 Wh. 2x 100Ah LiFePO4 batteries and 4x 160 W panels would suffice for both Essential and Essential and Optional. When I reached out to Battleborn, my working estimate was 2496 Wh. I attached a document with the calculations.

2) Are there value and compatibility gains to be achieved in going with Battleborn and Victron brands versus other suppliers' packages using different brands? The prices for components in the recommended system seem higher than I am seeing for these other packages as well as those that people are saying that they have paid to install their systems in various forums for 25 foot motorhomes.

In summary, I am OK with building a more robust system than we need. And, I do not mind paying extra for quality and longevity. I am seeking some guidance from folks who have blazed this path ahead of me.

Thanks,

[TitanMike]

Originally Posted by Bertha17

Sorry for the length of my previous post requesting input on our Solar/Lithium Upgrade. No feedback so far. So, perhaps just too much to read. Assuming that I will get past my reality check questions on Watt hour consumption/discrepancies and figure out the installation nuances, I hope that you might provide some feedback.



1) Does the Recommended System (for 2496 Wh/day) 1x 270Ah LiFePO4 and 3x 220W panels, seem reasonable and right sized? I calculated our Essential items to be 1803 Wh. Including Optional items, I came up with 1956 Wh. 2x 100Ah LiFePO4 batteries and 4x 160 W panels would suffice for both Essential and Essential and Optional. When I reached out to Battleborn, my working estimate was 2496 Wh. I attached a document with the calculations.



2) Are there value and compatibility gains to be achieved in going with Battleborn and Victron brands versus other suppliers' packages using different brands? The prices for components in the recommended system seem higher than I am seeing for these other packages as well as those that people are saying that they have paid to install their systems in various forums for 25 foot motorhomes.



In summary, I am OK with building a more robust system than we need. And, I do not mind paying extra for quality and longevity. I am seeking some guidance from folks who have blazed this path ahead of me.



Thanks,

Let's just say that I've never been unhappy to pay for the quality and reliability of my Battleborn batteries as well as the Victron charger, battery monitor, smart solar controller, and DC-DC charger for charging while traveling.

Batteries are starting their 5th year which for me is pretty much year-round and have been delivering on their reputation.

The Victron equipment communicates with each device across a network and can be monitored/controlled via a single Bluetooth app.

You can buy cheaper but doubtful you will find better.

I started with a patchwork of equipment after upgrading to lifepo4 batteries. I've replaced all but the Victron BMV-712 with Victron equipment.

Kind of proves the saying "It's not how much you spend, it's how often you have to spend it".

[tomkatb]

Installed two SOK 205 amp batteries two weeks ago.

Took ten minutes to replace 4 gc2 batteries. 7 hours in the emergency room. I sort of dropped a battery on my finger. More than a two band aide job.

The batteries are 12”x12”x8”. Do not fit everywhere. I will have room for three!

Mine have a built in battery monitor. Without solar my converter charged with shore power to 95% charge. Actually at 212 amps. Pleased so far.

My converter with the optional device that will top off my batteries at 14.4. Have not tried it yet.

Bms works. It was too cold to charge one day.

These are the odd sized batteries. However I think I can get three in the factory space. My box is 12.5”x28” x15” height.

[TomAR]

I needed to change BIM as well, so Li batteries would charge while driving.

[IMG][/IMG]

[JLeising]

[QUOTE=TomAR;2831950]I needed to change BIM as well, so Li batteries would charge while driving.[QUOTE]

The dc-to-dc listed will charge the Li batteries while driving. The BIM is usually eliminated in a dc-to-dc install.

[TomAR]

Ah-ha.
I should have noted I do NOT have solar.
Thanks.

[Bertha17]

TitanMike, That is quite a ringing endorsement of Battleborn and Victron products. Both for how you changed out other brands for them, and how well they work together for you. I truly appreciate you sharing your wealth of experience with me and others. 15,000 posts! I will most likely go this way once I nail down the sizes of the battery bank and panel array.

[nvs4602]

I did the battery upgrade first. I built a 280ah lifepo4 battery that has just a tad larger foot print than a single group 27 battery. I installed it inside under the dinette seating. I installed the DC-DC charger in the battery box in the steps along with a positive and negative busbars. This was a big improvement over the lead acid batteries. I left the lights on in the RV along with TV and residential refrigerator running off of the inverter. And it lasted a little over 22hrs before the BMS shut off the battery.


The victron 100/50 will be good for the 600watts but not any more. It is ok to add an additional Solar charge controller for more panels if when you need them.

[Bertha17]

Tomkatb,
Sorry you got SOKed by your new batteries. Hope they treat you right the rest of your journey together. Seems great so far. My battery box is under the entry steps (10"x23"x12" tall). Not large enough for the 270Ah Battleborn. Not sure where I would put it. Maybe the adjoining exterior compartment and use the battery box area for some of the other components.

TomAR,
Thanks for sending the before and after pictures of your BIM.

TomAR and JLeising,
How did you address concerns with the max charge rate amps that would be pulled from the Mercedes alternator by a BIM or DC-DC charger? I have not been able to find information on how to ensure a full charge and that there is no damage to the alternator.

[DogFather]

Once you do your calcs, suggest you factor for the following:

Do you ever camp where your roof is shaded by trees?
is there a particular season that you camp - like summer when the sun is high and you get more energy into your panels or winter when the sun is lower in the sky?
Do you camp in areas like the NW where it rains or is cloudy a lot or, say, AZ where sunshine's more abundant?
Do you prefer to minimize your generator usage to recharge batteries - is that a consideration?
Might you be increasing your energy consumption in the future?
When your batteries are depleted, how fast would you like to replenish them once conditions improve.

I found that these considerations are not quantifiable. So, my conclusion was that, to minimize generator usage, one can never have too many panels and batteries (within reason). Never heard anyone griping about having too much roof wattage or battery capacity.

[TitanMike]

Originally Posted by Bertha17

Tomkatb,

Sorry you got SOKed by your new batteries. Hope they treat you right the rest of your journey together. Seems great so far. My battery box is under the entry steps (10"x23"x12" tall). Not large enough for the 270Ah Battleborn. Not sure where I would put it. Maybe the adjoining exterior compartment and use the battery box area for some of the other components.



TomAR,

Thanks for sending the before and after pictures of your BIM.



TomAR and JLeising,

How did you address concerns with the max charge rate amps that would be pulled from the Mercedes alternator by a BIM or DC-DC charger? I have not been able to find information on how to ensure a full charge and that there is no damage to the alternator.

Can't speak to BIM's but DC-DC chargers can be programmed for charge voltage and are usually purchased by current rating that works with alternator size.

For example my DC-DC charger maxes at <20 amp as my alternator is a small one (130amp). Many vehicles later than mine have alternators well into the 200 amp range and can feed 50-60 amp+ DC-DC chargers.

[JLeising]

I have a Renogy 20 amp dc-to-dc charger. Data sheet says it can draw 150% of output current - so 30 amps (I measured 27 amps bench testing it before installation). Mercedes says 40 amps max for auxiliary battery charge, I understand.