Tweet
This year I began an effort to give my electrical system a bit more capacity and I thought I would document my effort here. I hope for feedback and if this can help others in who are considering a move to lithium or help me with my next stage that would be great.
Problem:
Using the group 24 battery provided by the dealer we are unable to camp for 24 hrs. We even found that the battery was drawn significantly with just a single overnight of camping.
Analysis of issue:
GD installed a GE 12v refrigerator at build time. This refrigerator draws between 6-8amps during each cycle. Given the typical draw the refrigerator only needs to run for roughly 6-8hrs total to drain a lead acid battery below a usable amount.
Goals:
We really wanted to camp for a weekend at a forest service campground without plugging in the generator.
What were the guardrails:
Cost was definitely a factor and so was time.
I needed to have the power necessary to camp for two days
Create a foundation for future expansion
Reuse components as I could
Where did I end up:
Installed an Ampere Time 200AH battery with a 200amp BMS. I installed this in the front bay of our 2800BHS.
Charging the system.
I needed to find a way to charge the system without a full rewiring effort, so what did I do.
The battery came with an AC 20amp charger. I plugged this in inside the front bay. I decided to go this route to limit the need to run new wire for a larger converter. I unplugged the existing converter from the AC panel in the camper and only used that charger for AC charging.
I specifically purchased wanted to extend my time without being plugged into AC. To support this I installed two things:
1: A Renogy 20amp DC-DC charger.
2: I also added an additional 100watt panel wired in series with the existing solar setup:
- 165watt furrion panel attached to a 25amp furrion solar controller.
Monitoring the system
I used a Victron shunt to monitor the system. This is how I determined that the refrigerator draws between 6-8amp during a normal cycle.
What were the findings:
- The DC-DC charger is the allstar. Right after we installed the setup we went on an 8 day tour visiting Mammoth Cave and Smoky Mountains. The DC-DC did a great job of charging the battery in between stops.
- My math was wrong when building my solar system. I have seldom seen what I want out of the system even under full sun.
- The Lithium battery really is amazing. I can get 2 days out of the system relatively easily.
- The GE refrigerator is a problem. Sometimes the compressor will run for a full hour at a time and that really is too much. I don't know what others with the GE are seeing but it really does suck the juice.
- I did use some 10awg wire I had to move the battery to the front bay. This really is a bit much for the draw of the slide and I notice it when moving the slide in and out.
- GD really had something against bus bars when building this camper. There is not one bus bar in this system and it made installing a bit of a pain.
- Hey GD, what is with the Furrion parts? Furrion is against standards based connections and it increased complexity in my solar setup.
- No matter what you need to understand what your system is doing so plan for a shunt install.
What's next:
- I need to increase the wire size away from 10awg in a few places and mount positive and negative bus bars. It creates a painful setup with way too many wires running all over.
- I need to redo the math on my solar setup and likely change to a different controller. My math(which was likely faulty) was based on a couple of limits dictated by the Furrion charge controller and a desire to minimize cost.
Overall Learnings:
Lithium Battery
- I see a lot of posts about moving to Lithium and I do think it's worth it. There are a lot of considerations though, especially charging. I tried to solve a lot of problems at one time, probably more than necessary but it worked well for our second half of summer trips. There are temperature considerations with Lithium which will play directly into budget. I purchased a budget Ampere Time battery which works well but does not have a low temperature cutoff.
Solar
- Watch your math, you can mix and match panel brands and capacities but it will impact the system
DC-DC Charger
- This is a no brainer. We have an F-250 which can push 20amp down the charging wire (even though it does not). Wiring this directly to your house battery can cause real issues so I believe this is worth it. Someone may ask what issues:
Others have covered this in more detail but there are two:
- The lithium battery can draw 200amps and this would cause issues in the truck
- Lithium needs a voltage of 14.4v to fully charge the battery. That is not possible with a stock vehicle charging system
RV Dealer
- Don't depend on your rv dealer to know how to build the system. When we purchased our camper in March I knew that battery capacity was going to be an issue, but our dealer didn't know anything about a move to Lithium. They actually told me they didn't do Lithium because they did not have the ability to fill it.
Summary
In sum it was a great project. I enjoyed it but I enjoy things like this. There are ways it could have been easier and with fewer components but I had some limits I wanted to stay within and it drove me to make certain decisions. Next summer I'll likely add more battery and totally redo the solar system, but as long as I'm having fun and I can afford it I'll keep playing
Problem:
Using the group 24 battery provided by the dealer we are unable to camp for 24 hrs. We even found that the battery was drawn significantly with just a single overnight of camping.
Analysis of issue:
GD installed a GE 12v refrigerator at build time. This refrigerator draws between 6-8amps during each cycle. Given the typical draw the refrigerator only needs to run for roughly 6-8hrs total to drain a lead acid battery below a usable amount.
Goals:
We really wanted to camp for a weekend at a forest service campground without plugging in the generator.
What were the guardrails:
Cost was definitely a factor and so was time.
I needed to have the power necessary to camp for two days
Create a foundation for future expansion
Reuse components as I could
Where did I end up:
Installed an Ampere Time 200AH battery with a 200amp BMS. I installed this in the front bay of our 2800BHS.
Charging the system.
I needed to find a way to charge the system without a full rewiring effort, so what did I do.
The battery came with an AC 20amp charger. I plugged this in inside the front bay. I decided to go this route to limit the need to run new wire for a larger converter. I unplugged the existing converter from the AC panel in the camper and only used that charger for AC charging.
I specifically purchased wanted to extend my time without being plugged into AC. To support this I installed two things:
1: A Renogy 20amp DC-DC charger.
2: I also added an additional 100watt panel wired in series with the existing solar setup:
- 165watt furrion panel attached to a 25amp furrion solar controller.
Monitoring the system
I used a Victron shunt to monitor the system. This is how I determined that the refrigerator draws between 6-8amp during a normal cycle.
What were the findings:
- The DC-DC charger is the allstar. Right after we installed the setup we went on an 8 day tour visiting Mammoth Cave and Smoky Mountains. The DC-DC did a great job of charging the battery in between stops.
- My math was wrong when building my solar system. I have seldom seen what I want out of the system even under full sun.
- The Lithium battery really is amazing. I can get 2 days out of the system relatively easily.
- The GE refrigerator is a problem. Sometimes the compressor will run for a full hour at a time and that really is too much. I don't know what others with the GE are seeing but it really does suck the juice.
- I did use some 10awg wire I had to move the battery to the front bay. This really is a bit much for the draw of the slide and I notice it when moving the slide in and out.
- GD really had something against bus bars when building this camper. There is not one bus bar in this system and it made installing a bit of a pain.
- Hey GD, what is with the Furrion parts? Furrion is against standards based connections and it increased complexity in my solar setup.
- No matter what you need to understand what your system is doing so plan for a shunt install.
What's next:
- I need to increase the wire size away from 10awg in a few places and mount positive and negative bus bars. It creates a painful setup with way too many wires running all over.
- I need to redo the math on my solar setup and likely change to a different controller. My math(which was likely faulty) was based on a couple of limits dictated by the Furrion charge controller and a desire to minimize cost.
Overall Learnings:
Lithium Battery
- I see a lot of posts about moving to Lithium and I do think it's worth it. There are a lot of considerations though, especially charging. I tried to solve a lot of problems at one time, probably more than necessary but it worked well for our second half of summer trips. There are temperature considerations with Lithium which will play directly into budget. I purchased a budget Ampere Time battery which works well but does not have a low temperature cutoff.
Solar
- Watch your math, you can mix and match panel brands and capacities but it will impact the system
DC-DC Charger
- This is a no brainer. We have an F-250 which can push 20amp down the charging wire (even though it does not). Wiring this directly to your house battery can cause real issues so I believe this is worth it. Someone may ask what issues:
Others have covered this in more detail but there are two:
- The lithium battery can draw 200amps and this would cause issues in the truck
- Lithium needs a voltage of 14.4v to fully charge the battery. That is not possible with a stock vehicle charging system
RV Dealer
- Don't depend on your rv dealer to know how to build the system. When we purchased our camper in March I knew that battery capacity was going to be an issue, but our dealer didn't know anything about a move to Lithium. They actually told me they didn't do Lithium because they did not have the ability to fill it.
Summary
In sum it was a great project. I enjoyed it but I enjoy things like this. There are ways it could have been easier and with fewer components but I had some limits I wanted to stay within and it drove me to make certain decisions. Next summer I'll likely add more battery and totally redo the solar system, but as long as I'm having fun and I can afford it I'll keep playing
Comment