Help with Battery Decision

[F350guy-JAY]

When I picked up the Pinnacle yesterday the 2 Trojan 6 volts were almost dead. It had not been hooked to shore power during the week it was there getting the new roof applied. The jacks wouldn't operate. Fortunately the shop had a shore power hook up and that got me going. Same thing happened when we got home after a 3 hour drive. I had to connect it to my shore power to get the jacks going. The batteries aren't quite 4 years old. I've had several sets of these batteries thru the years and they lasted up 7 years. I will do a load test on them tomorrow.

Which leads to my question. I consider us light battery users as really the only time its not on shore power is when we are traveling or an occasion like yesterday. No boondocking, ever, and no solar. We have a Xantrex 1200 watt inverter and a Progressive Dynamics PD4560K18NS2B converter/charger. I'm not sure but I think the only thing the inverter runs is the Whirlpool 21cf residential fridge and maybe a few outlets.

At this point I'm thinking about going to lithium, if possible. I'm not sure what I would need but was looking at a 200ah model or maybe 2 100ah's. A single 100ah may be enough but I guess having too much is better than too little. Also, I'm not sure the converter is lithium capable. The user guide says there is an optional output mode switch for lead acid and lithium but I'm not sure if my 2020 model would have that. I'm not sure where to look.

Sorry to be so wordy but I wanted to give some background. Maybe someone can help me figure it out. My bass boat has 4 lithium batteries and they are amazing, which got me to thinking about some for the rv.

 

[Route 66 Traveler]

I replaced my 2 flooded 12 volt batteries with one Renogy 100 amp hour AGM battery. Lessened my tongue weight and cost less than lithium, but the AGM is heavier than lithium. We seldom boondock, don’t have solar and are plugged in or run our generator most of the time. Works with my converter just fine.

 

[bill3kirk-JAY]

In regard to the 4560 I went through this with my 4590 but all the 4500 series should be the same. Mine was manufactured in 2018 and the switch was not on the front. I had to use the jumper setting which was on the main board. I attached both sets of instructions. I have 4 200ah lithium but I'm also using all Victron equipment with a MultiPlus-II 2X 120v, 3000A Inverter/Charger. I ended up disabling the charging feature of the 4590 because it is a single stage charger compared to the Victron multi-stage. However, the 4590 and the 4560 will do just fine keeping your Lithium batteries charged for your use. I found Progressive Dynamics Support to be excellent.

 

[Randyman69357]

I have a 300 amp hr. Battery coming as soon as Amazon gets there act together. First one was lost, second one was to be here yesterday and now shows the end of next week. My converter shows lithium capable on a sticker on the front. I believe it is the 4560 WI model. There is a tiny switch on the front of the fuse panel inside the unit that you switch from LA lead acid to LI Lithium. We have on factory solar panel and the same inverter and fridge as you do. We don’t boon dock, but do some Wally docking and with the fridge, 2 basement freezers and my wife’s CPAP, the generator set on auto start at 12 volts would start usually around 4am. Currently I have 4 LA AGM 160 amp hour batteries that are 2-1/2 years old.

 

[F350guy-JAY]

Bill K, extremely helpful. I will go out later and see what I have.

Randy, which battery did you order? I have some Amazon credit card points.

One point that got me to thinking about a lithium is how strong they are in my bass boat. I have a 36 volt trolling motor with 3 50 amp Ionic batteries and I can fish all day if I want and the batteries will only drop to around 80% charge. Another point is the way they hold their charge. I last used my boat in late October and have not charged the batteries. I did a check a few days ago and they are still at full charge.

I'm not understanding the difference in the charge modes for lead acid and lithium. It says continuous charging for lithium. Does that mean as long as I'm hooked to shore power that the battery is getting a full charge even if it is fully charged? Doesn't sound good but maybe it is.

 

[ARoamer]

--->>>>>I'm not understanding the difference in the charge modes for lead acid and lithium. It says continuous charging for lithium. Does that mean as long as I'm hooked to shore power that the battery is getting a full charge even if it is fully charged? Doesn't sound good but maybe it is.[/QUOTE]

Lithium aren't as fussy as lead acid when charging and don't need different charge and voltage levels. A decent 100AH lithium can take 100A of charge current, and when it's fully charged the battery's electronics will not allow any more charging until needed. There is a cell equalization mode but that is done automatically by the battery's electronics when nearly fully charged.

 

[F350guy-JAY]

Thanks Roamer. I thought that would be the case. I checked our converter and it does have the LA/LI switch inside the panel. I guess that means I'm good to go. Now to decide which battery and what amp hours to get unless there's something else I'm missing.

The Trojans have run down on me several times so I'm thinking I will just go ahead and replace them. Our first trip is with some of the grandkids over spring break next month. Wish me luck.

 

[Randyman69357]

I ordered the JSD solar 300 amp hr lithium battery. It comes with Bluetooth built-in so you can monitor your state of discharge and everything without having to add a separate shunt.

 

[RogerR]

Now that I have a Renogy lithium and 200 watts of Renogy solar. Paid a bit more than some of the Amazon/ebay sellers but like the warranty and Renogy has given me advice on use and care plus installation as I never had solar before.

Bluetooth and a good BMS ( battery management system) built into the battery gives me the knowledge of what my battery and solar is doing.

 

[Edutron]

We run 4 six volt VMAXTANKS 225 Ahr AGM batteries in series parallel for 450 Ahrs. Made my own cables and bat connectors. Added a second solar panel to upkeep charging when driving. No problems dry camping. We go no more than 2 weeks dry camping and have a gas generator witha 15 gallon gas tank in storage. Works great. Shop for deals at factory.

 

[Pacman1214]

Also remember that you will want a shunt based battery monitor if you switch to lithium, voltage based meters don't work for lithium. Some of the most highly regarded ones are the BMV 700, BMV 702 or BMV 712 from victron, but there are much cheaper ones that should work just fine from other manufacturers. I have a bunch of victron components in my trailer solar system and they have all been flawless

 

[RDTC]

I installed 3 200 AH lithium batteries, Victron inverter/charger, DC-DC charger, and other electrical system hardware. Mounted the batteries on a battery tray. Added a switch on each battery. With the switch, if needed I can isolate a battery off in reserve.

With your situation, I would recommend going with 2 moderately sized lithium batteries (150+ AH each). No need to install the Victron style inverter, you do not need the additional capabilities. I would recommend installing a larger DC-DC chargers.

 

[colby-JAY]

Another option is that if your converter is not lithium-compatible, and you are almost always plugged in (which is sounds like you are from your description), would be to bypass the original converter (pull the fuse), and install a small lithium charger closer to the batteries that just plugs in to an AC outlet. Or, depending on your power center, your converter may be able to be easily pulled out and replaced with a lithium-compatible one.

 

[F350guy-JAY]

Thanks everyone. Still debating my choices but need to decide soon as we are taking a trip during spring break in a few weeks. I mentioned above that I did verify my converter has the LA/LI switch on the circuit board. Looks like I need to do some more research as I'm not familiar with a DC to DC charger but if my converter is lithium capable not sure if that is necessary. I have heard that I may need to do something with the charge line from my truck.

 

[Randyman69357]

No real reason to have a dc to dc charge setup from your truck unless you are serious about off gridding and need that to top your battery off. I’m switching to lithium because of the long discharge rate for an overnighter at Walmart etc. The solar panel will throw some charge at it as well as your truck, although very small charge rate, while traveling to your next stop. I can recharge mine through my onboard generator or when I plug in at the next campground. Each person’s needs are different, but I find the lithium strategy to be in MY best interest compared to the AGMs I currently have. My battery finally came in and of course I’m out of town for a couple days, so can’t put it in until Thursday.

 

[F350guy-JAY]

No real reason to have a dc to dc charge setup from your truck unless you are serious about off gridding and need that to top your battery off. I’m switching to lithium because of the long discharge rate for an overnighter at Walmart etc. The solar panel will throw some charge at it as well as your truck, although very small charge rate, while traveling to your next stop. I can recharge mine through my onboard generator or when I plug in at the next campground. Each person’s needs are different, but I find the lithium strategy to be in MY best interest compared to the AGMs I currently have. My battery finally came in and of course I’m out of town for a couple days, so can’t put it in until Thursday.

Let us know how it goes. I finally pulled the trigger on one today. I decided on the Renogy 200AH Core battery, thanks to some sage advice from RDTC. It had the specs and features I think I need. For $20 more they include their $107 shunt based monitor which I think will be nice to have. I got notice it has already shipped.

My next issue is the charger. My converter has a lithium setting but it is a constant 14.6 volt charge. The current chargers are 2 stage starting with 14.4 and then down to 13.6. I know there are several plug in chargers that will work but just have to decide which way to go.

 

[Randyman69357]

My understanding is the BMS in the battery controls the charge rate, so it is ok for the converter to put out the constant 14.6.

 

[colby-JAY]

Let us know how it goes. I finally pulled the trigger on one today. I decided on the Renogy 200AH Core battery, thanks to some sage advice from RDTC. It had the specs and features I think I need. For $20 more they include their $107 shunt based monitor which I think will be nice to have. I got notice it has already shipped.

My next issue is the charger. My converter has a lithium setting but it is a constant 14.6 volt charge. The current chargers are 2 stage starting with 14.4 and then down to 13.6. I know there are several plug in chargers that will work but just have to decide which way to go.

The converter in Lithium should have a bulk and absorption mode. For example, the WFCO 8950 does bulk at 14.6v and then absorption at 13.6v. Progressive Dynamics PD9300 has a charge (bulk) mode of 14.4 and an idle (absorption) mode of 13.6.

SLA profiles usually have 3 modes - Bulk, Absorption and Float (say 14.4, 13.6 and 13.2).

I would check the specs of your converter, it should have two modes for Lithium

 

[F350guy-JAY]

The converter in Lithium should have a bulk and absorption mode. For example, the WFCO 8950 does bulk at 14.6v and then absorption at 13.6v. Progressive Dynamics PD9300 has a charge (bulk) mode of 14.4 and an idle (absorption) mode of 13.6.

SLA profiles usually have 3 modes - Bulk, Absorption and Float (say 14.4, 13.6 and 13.2).

I would check the specs of your converter, it should have two modes for Lithium

My PD4560K is not new enough to have the 2 stage charging for lithium batteries. It has a lithium setting but it's a constant 14.6 volts. I've been looking at the PD9300 series and it does have the 2 stage charging. I've also looked at PowerMax PM3 Lithium Plus series which also advertises the 2 stage lithium settings. It's half the price of the PD9300 which makes me wonder if it is half as good. I haven't looked at the WFCO brand.

Randy, I did call Renogy and asked about using my older style converter with the single lithium setting. The person I talked to tried to find the answer but finally did a ticket to get it to their engineering department. Here was their answer I got in an email: "Overvoltage for the battery is 15V. The 14.6V on you converter will be okay as long as the charger has a lithium setting otherwise it won't charge the battery completely." I'm not quite sure if it's saying use it or if the lithium setting they refer to is the newer 2 stage.

 

[RogerR]

I don't have a lithium setting but I talked to Renogy and regular lead setting will not harm the Renogy battery. As above, battery will not accept to high a rate of charge, to high or low a voltage and will not discharge faster than a certain rate ( 50 amps on mine). It also will not allow a charge below freezing or when to hot. There is a built in temp gauge that you can see on Bluetooth!