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Topic: Lithium battery upgrade (Read 928 times) previous topic - next topic

Lithium battery upgrade

Hello all,

I'm new to this forum and a first time owner of a 1990 FT GV Uni home. I've been lurking here for about a year and finally decided to make an account. I've been able to figure out many of the answers to my questions by researching here, but I have questions I haven't been able to flesh out.
Right now I'm working on getting my solar installed and upgrading the batteries to lithium.
I'm mounting 3 325watt 24 volt panels. I've read that some use 3m VHB tape to mount the panels. Is this a long term solution? I mean, everything else up there is screwed down! If VHB tape is that good, why penetrate with screws at all? That being said, I am open to using the tape if it works.

I know lithium charge differently than gel or lead acid. I've got a nice charge controller for the solar side. It's the components on the coach I'm iffy about. I have an Inteli-power 9100 model pd9180A. I plan to replace it with model pd9180ALD, which has built in BMS. Does anyone have any experience with this?
I'm also not clear about my alternator and what the best course of action is to take with it. Where is the alternator introduced into the system? Meaning, where does the wire from the alternator go? Is it direct to the batteries or is there a relay or something? And, is there some kind of smart charge controller I can put in line so I don't waste my batteries?

I really appreciate you all and your collective knowledge!
Thank you in advance,
Erik

Re: Lithium battery upgrade

Reply #1 –
AM Solar uses the tape on their installs. I bought their brackets that come with the tape and installed my solar system. They have a self help on their website that shows how to use the install with the tape. I haven't had any brackets come loose and have driven is some very bad wind storms. As far as the alternator I am using a B2B but there are other options that someone will probably comment on.

Re: Lithium battery upgrade

Reply #2 –
Your alternator probably goes to an isolator that's mounted in a rear wheel well. I don't know that you have to change anything there. I haven't installed lithium batteries so I'll let others chime in. Your solar panels should go directly to your charge controller and then to the batteries and the charge controller should have a setting for lithium batteries but I have heard that a charge controller setting for sealed lead acid batteries is close enough for lithium. 

Re: Lithium battery upgrade

Reply #3 –
A Victron Orion non isolated charger (B2B) would provide a programmable and safe charge from your Alternator to Lithium house battery bank in place of an isolator. Renogy also makes one, but if you use a Victron solar charger then the Orion makes sense.

I also made brackets and attached them with VHB tape. Five years and holding well; use a high quality caulk around brackets to prevent water intrusion on tape. I also spent a lot of time on the AM Solar site. Great videos, watched them all. You can read my post of installing Orion from February 2022.

Re: Lithium battery upgrade

Reply #4 –
What amperage would you recommend on the B2B? I have 900ah of batteries.

Thanks again!

Re: Lithium battery upgrade

Reply #6 –
I made brackets that are very similar to the ones sold by AM Solar and installed them with VHB tape. I have only had them on for a year, but so far no problems. I sanded the areas where the brackets are taped to the coach, used the 3M primer to clean the surfaces where the tape is attached, and cleaned the aluminum bracket surfaces with Toluene to remove any oil from my hands before priming. I also bought a steel hand roller from Amazon to ensure I was getting enough pressure on the tape when I attached it to the brackets. When I mounted the panels to the roof, I made sure I applied as much pressure as I could, using mostly my body weight. I then sealed around the brackets with 3M 4000 sealant to keep water out. If you are interested in making your own brackets, PM me and I can give you more details. The deciding factor for me as far as making them vs. buying is that I have more surplus time than money, but others may have the opposite.

Are three 325W panels all you can fit? I ask because you say you have 900Ah of batteries, so I assume you expect to use your batteries a lot. We have 700Ah and 1600W of panels (1800 when I use my portable panel) and I wish I could add more. I recommend as many panels as you can fit. As for charging, if your charger does not have a lithium setting, you may be able to use a generic AGM setting; ask the battery manufacturer. For alternator charging, I use a battery isolation manager,  but a lot of others  swear by B2B chargers.

Re: Lithium battery upgrade

Reply #7 –
I was planning on emulating the factory installed bracket that was on the coach. There was a 20 watt panel affixed with two pieces of aluminum L brackets on each side. One bracket screwed to the coach and one screwed to the panel. Then the panel brackets and the coach brackets were bolted together. I'd be interested to see how you did yours though.

My 3 panels were given to me, so I had em just laying around the past couple of years waiting for a project. They're pretty large and I haven't mapped out how they're going on the coach yet. If there is room after the install I may add another panel or two. I figured I could supplement with the generator when need be. With the size of the propane tank, I could probably run my generator a couple hours a day for a year and still not run out of LP. I also replaced the water heater with a Furrion tankless LP.

I'm in the process of changing all the lights to led, inside and out, so that'll help.

Did you wire your panels parallel or in series or a combination?

Re: Lithium battery upgrade

Reply #8 –
I wired my panels all parallel others have done series. If one panel is in the shade when in series depending on location you would lose all the panels I wired 2030 watts all parallel with 2 solar chargers. so shade would not have as much as an effect.

Re: Lithium battery upgrade

Reply #9 –
I also wired my panels in parallel (6). I have (4) 300watt panels that feed into a MPPT controller and (2) 360watt panels that feed through a separate MPPT controller.
I know MANY attach there panels with the VHB tape. I don't feel comfortable just using an adhesive on my roof to anchor such a heavy device as a solar panel.
The thought of a panel going air born and striking somebody else scares the crap out of me.
I glued and drilled through the roof to anchor my panels for MY OWN piece of mind.

My panels feed (10) Lifeline L16, 6v, 400 ah (@20%) AGM, batteries.

Re: Lithium battery upgrade

Reply #10 –
You will find that your propane generator uses 1 gallon per hour and you have what a 45 gallon tank, so 45 hours maximum running.

Re: Lithium battery upgrade

Reply #11 –
I appreciate all of your input. I'll eventually be adding more solar on an another charge controller later. As for now, I don't plan to be off grid for too long at a time. A week or two at the most. So when I come back in I'll be able to fill the tanks.
Been busy bringing the coach back up to par. Resealing all the roof mounted stuff now and fixing what seems like a million little things. Also adding a couple of audio amps with upgraded speakers and a sub so I can actually hear my audio books cruising down the road.

Thanks again!