Lithium upgrade and converter replacement options

[NeoNate77]

Hello all. Have a question about converter bypass. Currently own a 2021 Eagle HT 312BHOK. Trailer came with one garbage 100ah battery when we bought. Quickly realized that wasn’t going to be enough so upgraded to 2 - 100ah AGM batteries in the generator tray (no room in pass through storage with stuff and no other internal place to mount) and added a 2000w inverter powering the pre installed inverter circuit as well as a separate line to power the mini fridge in the outdoor kitchen. Both wired with small automatic transfer switches. System works well except I am constantly down to 30% ish by the third day. I can run a generator 6 hours a day total. It’s a combination issue of capacity and charging ability. The AGMs certainly aren’t going to last long at 70% dod. Solar is not an options as there is heavy tree cover and it’s in a glen. Lithium seems like the ideal solution. I purchased 2 - 140ah group 31 size batteries. I have a progressive dynamic PD4060 that does have a lithium switch. Reviews of this converter in lithium mode are pretty mixed. It is a single stage constant voltage charge, which is good for fast charging, but not so good for lithium lifespan. Progressive dynamics DOES make a 2 stage lithium converter, but it doesn’t appear to be compatible with the PD4060. I am looking to find the best way to bypass this converter and utilize a Victron IP43 50A smart charger instead. If mounted by the power panel, I can use the existing wiring and wire in AC and use existing battery wires. The question is how to go about bypassing the converter. I saw a suggestion on another site of wiring in to existing wiring and simply turning off the converter breaker. This certainly simplifies wiring and leaves the onboard converter as a back up option if the victron fails. I am aware the converter is also a power supply, providing 75A of DC power (60A charging) but I don’t think that will be much of an issue as the high discharge ability of the the lithium should make up for that slight boost in amperage. Or, do I just take the converter wiring completely out, mount the Victron charger in the pass through by the bus bar and call it a day. Opinions? Better options? In a perfect world, I would just by a Victron Multiplus and let it do its things, but since that’s definitely not in the budget right now, I’m thinking this is the way to go.

For reference, I have a Victron Orion DC-DC charger already installed with a bus bar and a smart shunt (powermon) so I can fairly carefully monitor usage and current.

***I should also add my issue with constant voltage charge is the we camp at a few places with power and I don’t want to have to turn the batteries on and off constantly to avoid cooking them. The Victron is programmable so I can have them slightly discharge on float so as not to keep them at 100% all day every day***

 

[RogerR]

I have a single 100 amp lithium from Renogy. When I first got it I didn't have solar and was told my non-lithium rated system would charge it to 80%. But I found it would gently raise it to 100% over a couple days. Now that I have solar I don't even have the breaker on to the charging circuit!.
That said, how about just trying what you have and see how it works? You may find you don't need to spend money and time to make any upgrades.

 

[Jayhawk 29]

It sounds like you are trying to complicate things and cover all your bases. I see bunches of dollars and probably spend more time in rigging than enjoying, unless you pick a stationary place and stay put.

While you may not want to do some manual stuff to achieve your power capacity, every person's setup is different. Its fairly common to run a generator for a small boost, certainly not six hours unless you are consuming a lot of power or if you have equipment that demands loads of power to maintain a certain level of needs.

Being hooked to land based sources and the requirement for me to maintain the same amount of battery capacity when off the grid requires me to consider full sun. Of course this is not always possible and night time restricts my solar recharging.

So I live with my limitations and the manual changeover to the needs for my inverter and keeping the batteries up to snuff. I did not intend on creating a system costing me several thousands of dollars in materials for the advantage of all the available options of doing nothing. I rely on a generator for a boost on occasions , driven by the restrictive environment for solar recharging and do need to be mindful of not allowing my batteries to become to discharged. Its just part of rving when traveling and stopping in a wide range of locations.

 

[NeoNate77]

It sounds like you are trying to complicate things and cover all your bases. I see bunches of dollars and probably spend more time in rigging than enjoying, unless you pick a stationary place and stay put.

While you may not want to do some manual stuff to achieve your power capacity, every person's setup is different. Its fairly common to run a generator for a small boost, certainly not six hours unless you are consuming a lot of power or if you have equipment that demands loads of power to maintain a certain level of needs.

Being hooked to land based sources and the requirement for me to maintain the same amount of battery capacity when off the grid requires me to consider full sun. Of course this is not always possible and night time restricts my solar recharging.

So I live with my limitations and the manual changeover to the needs for my inverter and keeping the batteries up to snuff. I did not intend on creating a system costing me several thousands of dollars in materials for the advantage of all the available options of doing nothing. I rely on a generator for a boost on occasions , driven by the restrictive environment for solar recharging and do need to be mindful of not allowing my batteries to become to discharged. Its just part of rving when traveling and stopping in a wide range of locations.

I’d say the goal is rig once and not have to spend time worrying again. We camp a bunch of locations so I’m trying to adapt. We have a few medical things and 2 refrigerators that require the power so the generator is the worst case back up option. I’m not looking to spend money on unnecessary things, but I don’t want to constantly have to monitor and control my systems. I want it to be set up once and not have to touch it for the season and this seems like the most cost effective way to do that.

I consulted with Progressive Dynamics and they said the best option would be to simply wire in the charger to the existing bus bar in the pass through and turn off the breaker for the converter. This leave the converter as a back up option should I need it and greatly simplifies wiring. For what it’s worth, there is no 2 stage converter available from Progressive Dynamics that will fit with the PD4060, however if you have the room, you can use the PD9360V converter and deck mount it. That is the newer 2 stage converter. It is about the same price as the Victron (slightly more, in fact) so I will be going the Victron route.

 

[Jayhawk 29]

I get the feeling that you think you can operate on lithium batteries without a worry of charging , sometimes at a faster rate in cloudly days with a conservative aount of solar panels.

No matter what you wish to do in lieu of running a generator parttime, you still need a source to recharge your batteries, 100 ah flooded, AGM or any lithium that will produce enough power to run an inverter. AC units do not like to run on low voltage for an length of time , as a constant practice.


This comes back to solar. So both the solar and the battery setup needs to be matched accordingly. Even if you have lithium, at some point you will need to recharge them. While you can drain down the lithium without doing the same type of damage as you will experience with any lead acid flooded battery, to bring your lithium battery back up quickly enough to operate the inverter correctly.

Personally I always turn off my converter when off the grid and running on an inverter. Thats a given, because if you don't you are trying to recharge your battery by the inverter that's using the same 12 volt that your converter is attempting to charge.

If I am misunderstanding you, then please clarify my thinking. Any upgrade of a converter still needs 110 to operate, which you cannot do with the inveter.

 

[NeoNate77]

I am fine with running a generator to recharge. My inverter only powers 2 circuits with small transfer switches. I do not have a whole trailer transfer switch so I do not need to turn the converter off presently. The generator hours are 2 hours in the morning and 4 hours in the evening and this is not enough time to recharge my AGMs to 100% with the usage from the refrigerators and other necessities. The lithiums will increase my usable capacity from 100ah (200ah at 50% dod) to 224ah (280ah at 80% dod) and their increased charging rate will make up for the usage. The issue I was trying to address was the converter only being a single stage charger in Lithium mode and the long term effects of that when not at a camp with no sun or electric. The lithium specific charger will insure when on shore power, I don’t have to worry about constantly charging at 14.6v or having to constantly disconnect the batteries to save them from damage. I have 400w of solar capacity and 25 amps of charging from my DC-DC while traveling so I’m good under full sun conditions. We camp about 50% off grid and with full sun I am fine. It’s the no sun days/trips I am planning for, as well as maintaining the lithium batteries for as long as possible.

I guess the simplest way to put the dilemma I was trying to address was how best to maintain the lithiums with a lithium specific charger without having to constantly disconnect and reconnect the batteries from the converter when on shore power. My current converter, although lithium capable, is not ideal for lithium longevity.

 

[Jayhawk 29]

Great detail of your thoughts and arrangement, With my solar and the controller and the wires run from the controller to the batteries, the batteries are charged by the solar when I am not plugged into shore power. I don't turn off anything unless I am strictly running on my inverter. Then I just flip open my power panel door and turn off the converter breaker. That's a basic step and an easy one. FWIW I have the combination converter.

I actually wired my inverter, 2000 watt Renogy into my power panel so that I could use all 110 outlets. Of course I know my restrictions when running my inverter. I also installed a 110 residential fridge , which I run in addition to a separate min fridge for my bottle waters off of an additional cord from the outside receptacle when stationary. I have the luxury of having the built in power source in the bed of my truck when driving. So the fridge stays under my hard tonnoeu cover at all times. Even when its unplugged when we are using the truck, everything stays fairly cool.

 

[Jack Wireman]

I totally get your concern about cords and rain. Like a lot of folks here, we’ve camped through some heavy downpours without any major issues. But to be honest, I still like to have a little extra peace of mind, especially with our setup.

When we knew we were going to need an extension cord pretty often (some sites just aren’t close enough), we ended up investing in a heavy-duty RV extension cord that’s specifically made for outdoor and wet conditions. We got one that had thicker insulation and better weather resistance ratings than the basic ones — Islewire 50A Extension Cord(https://www.amazon.com/dp/B0CLY1MJ14?th=1) and 50A Power Cord (https://www.amazon.com/dp/B0CTJB14X4). It’s been awesome so far. The connection points are super tight and we haven't had to fuss with plastic bags or duct tape at all, even during some crazy Florida summer storms.

I still follow the old habit of keeping the connection off the ground when I can (either tucked under the trailer or up on something), but it’s nice knowing the cord itself can take the wet weather without worrying. Definitely made camping less stressful, especially for first trips out.

Hope that helps — and safe travels when your rig gets there!

 

[irwinr]

It sounds like your main concern is the PD4060 may damage your battery from constant voltage charging?

If that's the case: Save your time and money. As long as you're using LiFePO4 (LFP) batteries from a reputable brand: The constant voltage isn't going to materially harm them. As long as you have batteries from a reputable brand with a good BMS: The BMS in the batteries will shut off the charge current to protect the cells before letting the voltage reach a level that would harm them.

Floating the LFP's at a lower voltage, like 13.6, would certainly extend their lifespan by a small amount. But in general LFP doesn't mind being held at full charge all that much, unlike other lithium chemistries like NMC or NCA. But I've been using LFP batteries in everything from starter batteries for my trucks and tractors to UPS units to solar systems for RVs for 9 years now. I have batteries that have been in service in my UPS (uninterruptible power supplies) with constant voltage charging for 9+ years now that still capacity test to have 90% of their rated capacity.

Sure: if they weren't constantly held at 100% charge for 9 years straight they'd probably still have maybe 95% capacity... but ask yourself: is it really worth the time and effort to do what you're describing to save 5% capacity over a 9 year span?

If you're worried about lifespan: Keeping the batteries cool will have a MUCH bigger affect on their overall lifespan than the charge voltage. Make sure they aren't installed in a compartment with the inverter for example where the inverter will heat them up. I prefer to install mine inside the camper where the A/C will keep them cool in summer (and furnace can keep them warm in winter)