Lithium install with non-lithium Converter

[Mike & Rebecca]

Current trailer setup as delivered by dealer:
- 165W Furrion solar panel
- 50A Furrion MPPT solar Charge Controller - has settings for AGM, Lead/Acid and Lithium batteries.
- Progressive Dynamics 60A PD9260C Converter (non-lithium version I believe.)
- Two dealer installed Interstate "Dual Purpose" batteries - according to Interstate's website each has only 64AH reserve capacity.

With the Furrion 12V fridge draining off as much as 30-70Ah (according to other posts I've seen on the topic) this system is going to barely last 1 day - if that - before the batteries are below 50% SOC. Not a great set up with a 12V dependent refrigerator.

95% of the time we are in a park with electrical hookup, so I'm not currently interested in a major upgrade to the solar. Maybe later. However, I would like to be able to survive 24 hours before having to resort to the generator to recharge the battery.

My thought is to replace the 2 LA batteries with a 206Ah SOK (or equivalent Ah Lithium.) That seems a reasonable balance between cost and ease of installation. I read a discussion about whether or not a sufficient SOC can be obtained if the stock converter isn't swapped for the model that supports lithium batteries. There was a suggestion that the solar charger (which is lithium capable) might be able to get the lithium to full SOC, but I wasn't clear on the results of that discussion.

My question is can I drop in the 206Ah lithium battery without replacing the PD Converter with the Lithium model? Or will the performance of the system be so subpar that I really need to replace the Converter at the same time as installing the Lithium battery?

If I do swap for the Converter for the correct model, is it really as simple as disconnecting and reconnecting the existing leads to the existing Converter? I may be willing to attempt that as it's within my "one screw" tolerance for repairs I'll take on myself.

As for the battery replacement itself, I can just use the same battery leads that are currently serving the LA batteries and connect those to the new Lithium, correct? Or does wiring need to be changed?

And if my plans are just plain wrong, feel free to say so.

Thanks!

[Guest]

There are a variety of opinions on this where I believe the entire system should be compatible for optimum performance. The cheapest way to do this would be to replace your batteries with LiFeP04 models and install a WFCO switchable power center as a replacement that can be configured to operate with LFA or Lithium batteries. The is an inexpensive solution where additional wiring would not be needed.

https://parts.unitedrv.com/products/...-8955pec-b-lis

Jim

[Country Campers]

Check out post #9 in this thread Replacing Lead Acid Battery with Lithium - Grand Design Owners Forums (gdrvowners.com) this will give you an idea of how long the Lion Energy batteries lasted for me at 210 ah. The SOK batteries at 206 ah should give you about the same results, note that we were running the furnace which is a huge draw on the batteries.

In regards to the charger I agree with Jim above that there are varying opinions and results. I have heard that folks get anywhere from 90% to 95% SOC with non-lithium chargers , which is not really that bad the battery will just not reach the full state of charge. The other issue with the non-lithium charger is the amperage that the charger puts out. Most charger/converters in these units are 55 amp, which that is not what fully reaches the battery. The SOK battery lists that it can handle 50 amps of charge, the stock charger may reach this and may not, the only loss with this is it will take longer to charge at say 40 amps instead of the full 50 amps, not a big deal if you are not in a hurry. Mostly it comes down to what you want to do.

Brian

[acoleman43]

Mike & Rebecca, THat's a good question and I agree with your concern. I think both Jim and Brian gave some good answers and solutions.

Another option that might allow more flexibility, without any installation (but does cost some $$) is a portable power station. These are essentially large portable batteries. jackeryportablepowerstation.com is a good brand that offers models with output from 167WH to 1468WH. You can just plug these into the trailer at night to run fridge, fans, chargers....and it won't drain the "house" batteries (assuming your power consumption is within limits of power station). You can purchase portable panels to charge the power station during the daytime.

The advantage is you can bring this with you anywhere in any vehicle. Disadvantage is the high cost.

[Mike & Rebecca]

acoleman43 , thanks for that suggestion! I'll check that out before making a purchase decision on the battery replacement.

[Mike & Rebecca]

Check out post #9 in this thread Replacing Lead Acid Battery with Lithium - Grand Design Owners Forums (gdrvowners.com) this will give you an idea of how long the Lion Energy batteries lasted for me at 210 ah. The SOK batteries at 206 ah should give you about the same results, note that we were running the furnace which is a huge draw on the batteries.

In regards to the charger I agree with Jim above that there are varying opinions and results. I have heard that folks get anywhere from 90% to 95% SOC with non-lithium chargers , which is not really that bad the battery will just not reach the full state of charge. The other issue with the non-lithium charger is the amperage that the charger puts out. Most charger/converters in these units are 55 amp, which that is not what fully reaches the battery. The SOK battery lists that it can handle 50 amps of charge, the stock charger may reach this and may not, the only loss with this is it will take longer to charge at say 40 amps instead of the full 50 amps, not a big deal if you are not in a hurry. Mostly it comes down to what you want to do.

Brian

Thanks Brian! I read your post previously and was thinking of you when I posted this question. Your original intent and needs appeared to be pretty similar to mine. I think I'll bite the bullet and replace the Converter at the same time. The Progressive Dynamics lithium model (PD9160ALV) to replace my current PD model says the output is 60 amps so maybe that will provide the 50 amps the SOK requires. As my daughter says, we use the "bleep" out of our trailer and a few extra hundred dollars to do this right is perfectly ok with me.

[Country Campers]

Mike & Rebecca

We use our camper quite often as well so adding the few items that I did will add some "easier" times while camping as well as open up some other places that we have talked about going. It is nice to be a little more flexible in where we can go.

Brian

[howson]

Mike & Rebecca
My .02: upgrade the battery and get the right converter. If the budget will allow, a good battery monitor (of course I'm going to recommend the Victron BMV-712 or the SmartShunt). Based on your usage scenario, skip upgrading the solar and add the ability to charge your new battery from your truck. The latter is well beyond the "single screw" scenario, however, so it will involve finding someone to install it but it is the best way to ensure that the battery is at 100% SOC when traveling--even with the refrigerator running.

Lengthy thread as it covers from conception to installation, but it should give you an idea of what's involved. The capability is fantastic: https://gdrvowners.com/forum/operati...e-battle-borns

Guest -- did you do a write-up on your Renogy install? All I can find is the conversation here: https://gdrvowners.com/forum/operati...-dc-dc-charger Also found some here: https://gdrvowners.com/forum/operati...cle-connection

ncitro -- also can't find a specific write-up for your Renogy install. Did I miss it?

Howard

[ncitro]

Mike & Rebecca I agree with everything Howard said, I actually was going to comment about the shunt last night but decided to wait for you to reply since you'd already gotten done good advice and I didn't want to overwhelm you.

Looks like I didn't do a separate write up on my DC to DC charger, I posted my install in Howard's thread. Around page six. I'm such a fan of mine I've taken to recommending it before solar to most people. If you travel a lot of drive days it can mean the difference between "having" to make your overnight stops in a campground with power to recharge, and being able to pull into Walmarts or Cracker Barrels and not worrying about the power.

I've got 1,200 watts of solar on my roof and still would list the DC to DC charger as the best upgrade I've made.

https://gdrvowners.com/forum/operati...le-borns/page6

[Mike & Rebecca]

howson and ncitro that's excellent additional info! You've understood my needs and helping me keep this install to what's necessary and not the be-all-end-all. Definitely don't need that yet. Not sure it's easy to answer, but can I simply connect the new Converter and new lithium battery to the existing cables? Or do those need to be upgraded for some reason?

[Jlawles2]

I don't have a Lithium battery, Solar, and not planning a conversion just yet (limited dry camping).

BUT I have a question.
Without changing the converter / charger to a Li compatible unit it's agreed that the battery will not reach full charge. However, unless the solar panel is supplying more power than the camper is using, how will the charge difference be handled. What will converter do if the battery voltage is higher than it's output, can the solar charge controller see the converter charge supply and not kick out? I believe that all matching components that "talk" to each other can overcome some of these issues, but non communicating equipment tends to get sketchy in performing as expected.

[ncitro]

howson and ncitro that's excellent additional info! You've understood my needs and helping me keep this install to what's necessary and not the be-all-end-all. Definitely don't need that yet. Not sure it's easy to answer, but can I simply connect the new Converter and new lithium battery to the existing cables? Or do those need to be upgraded for some reason?

Yes, the simplest would be to just remove the old and install the new and move the wires. As long as you get the same size converter there should be no issue reusing the wires.

[ncitro]

I don't have a Lithium battery, Solar, and not planning a conversion just yet (limited dry camping).

BUT I have a question.
Without changing the converter / charger to a Li compatible unit it's agreed that the battery will not reach full charge. However, unless the solar panel is supplying more power than the camper is using, how will the charge difference be handled. What will converter do if the battery voltage is higher than it's output, can the solar charge controller see the converter charge supply and not kick out? I believe that all matching components that "talk" to each other can overcome some of these issues, but non communicating equipment tends to get sketchy in performing as expected.

The way I've always reconciled different voltage supplies in a circuit is that voltage leads the current. (Feel free to correct me if I'm wrong). That means essentially current will come from the highest voltage source first. Let's say your battery is fully charged at say 14v to make it easy, and your converter charges to 13.6. You turn on your lights and whatnot in the rig. Those devices will essentially draw from the battery until it gets to the converter voltage and then will draw from the converter. The physics involved is obviously more complicated than that. Now if you add a solar controller that charges to say 14.1, it'll feed those sources and start to charge the battery up to it's max. The converter will still be "on", but won't be pushing any current since it's voltage isn't the highest in the circuit.

I've simplified all this by having all my sources set to charge at the same voltage, my Multiplus, solar controller, DC to DC charger, and backup converter.

Hope that answers your question. If anyone thinks I'm off base feel free to correct me.

[Jlawles2]

ncitro Thanks Neil. Sounds logical, but I've had issues with various types of chargers getting "stupid" in seeing voltage from each other and thinking the batteries were charged when they were not. Hoping the solar chargers are "smarter" than that as they are typically used with various other chargers.

Maybe one day we will dry camp, but around here the weather is freeze or melt. In between only last for a few hours during the change over.

[ncitro]

Yeah we definitely do our dry camping mostly out west, but where we really like it is for overnights. It's nice to not worry about needing to find a campground on drive days.

I avoid the smart/dumb issues but setting everything to constant voltage/constant current. This is based on a recommendation from Lion Energy when I bought my batteries. Their suggestion is that for their batteries (and I assume most others off the same type) you do not want three or four stage charging, you want just constant voltage and it'll taper the current as it charges (at about 98% SOC in my experience).

I have the Multiplus and Victron solar charger set to fixed output. Same with my backup 100A converter (turned off unless I need to charge quickly with that and the Multiplus going). The DC TO DC is staged but at a higher voltage. If it's sunny out or I'm at a high SOC I keep that turned off, but in practice they're rarely full except for if we're leaving an electric site or home.