Planning Stage Switching to Lithium Battery

[Steven@147]

Sound like a great plan. Have you thought about adding a small solar set up to help keep batteries charged on travel days ?

Tami and I have talked about maybe getting an external suitcase style solar panel as backup for our backup generator case we lose AC power, or if we can't get fuel to keep the gen running. Solar - That's a whole nother ball game to figure out, capacity Vs usage.

 

[Steven@147]

Very good friends of ours in their mid 80s have a New Horizons RV. When they had it built a couple of years ago they went all out with 4 huge battleborn batts, solar panels covering the roof, cargo hold full of victron stuff including the multiplus, huge cables connecting everything and cutoff switches all over the place. A monitor to show whats going on with the system looks impressive. Overall a very impressive system and I expect it could have cost them somewhere in the neighborhood of 10-15 K or more. They don't have a generator.

Thing is they never boondock. They are always connected to AC power. It's just in case. I was talking to him and he admitted, he has a general knowledge of how things are supposed to work but has no clue how to troubleshoot the installed system if ever there's a problem.

To me that's a lot of money for just in case. And then I hope the system works trouble free for a long, long time and they have clear sky's for the solar panels to do the job if it's ever needed..

That's the thing Tami and I discussed as well, how much money (and time) to invest is a system (lithium batts and such) that's just in case we need it. We do have an external generator just in case and as long as we can get fuel it will run. On a tank of fuel the gen will run @ 8 hours. We carry a 5 gallon fuel can.

 

[SolarPoweredRV]

Very good friends of ours in their mid 80s have a New Horizons RV. When they had it built a couple of years ago they went all out with 4 huge battleborn batts, solar panels covering the roof, cargo hold full of victron stuff including the multiplus, huge cables connecting everything and cutoff switches all over the place. A monitor to show whats going on with the system looks impressive. Overall a very impressive system and I expect it could have cost them somewhere in the neighborhood of 10-15 K or more. They don't have a generator.

Thing is they never boondock. They are always connected to AC power. It's just in case. I was talking to him and he admitted, he has a general knowledge of how things are supposed to work but has no clue how to troubleshoot the installed system if ever there's a problem.

To me that's a lot of money for just in case. And then I hope the system works trouble free for a long, long time and they have clear sky's for the solar panels to do the job if it's ever needed..

That's the thing Tami and I discussed as well, how much money (and time) to invest is a system (lithium batts and such) that's just in case we need it. We do have an external generator just in case and as long as we can get fuel it will run. On a tank of fuel the gen will run @ 8 hours. We carry a 5 gallon fuel can.

Since you mentioned that you seldom Boondock your need for the generator would minimal at best. Additionally, since you will eliminate the need for Propane to operate the fridge, you have excess propane that you are carrying with you. I would suggest you consider getting a small Propane (Dual Fuel) generator to eliminate the hassle of carrying around that 5 gallon gas can. I have a Dual Fuel generator that has never been operated on gas. I really love the convenience of not having to carry around gas.

 

[Steven@147]

Since you mentioned that you seldom Boondock your need for the generator would minimal at best. Additionally, since you will eliminate the need for Propane to operate the fridge, you have excess propane that you are carrying with you. I would suggest you consider getting a small Propane (Dual Fuel) generator to eliminate the hassle of carrying around that 5 gallon gas can. I have a Dual Fuel generator that has never been operated on gas. I really love the convenience of not having to carry around gas.

Yeah a dual fuel genny would be ideal. At the time we bought our genny some years ago, they were hard to find and the one I really wanted was not available for months. Boy our genny sure came in handy during the big freeze out in South Texas a few years ago. Just before the winter storm hit I filled our 5 gallon can and it kept the genny running through the 4 days before power was restored. We came closer to running out of propane than gas for the genny. Had to conserve on everything.

I don't carry gas around with us, just the can but if I do have any gas left before traveling I donate it to other campers or campground lawn mowers,LOL's!

 

[Steven@147]

I did a little test yesterday just to see how things might work. How much power will be going into the battery to recharge it at a given SOC, and how long it might take to return the battery back to 100% or 105% SOC.

I just used the WFCO circuit breaker On/Off or the Lithium On/Off to control the test.

I don't know some good may come from my thread and somebody may get some good out it and my "cheapo" lithium conversion.

Rig is on AC power. I turned Off the WFCO charger, also the Lithium charger (directly connected to the battery) Off and let the rig run on the battery providing 12VDC all day starting at 100% SOC (State Of Charge) the battery finally got down to 73% SOC. Battery performance numbers all came from the battery WiFi app.
I did not test with both Lithium and WFCO chargers On, yet.

SOC=73%
Lithium On - WFCO Off
15.48 amps - 13.47 VDC - 202.98 watts ECT (Estimated Charge Time) 1 hr 48 min

SOC = 75%
Lithium Off = WFCO On
5.94 amps - 13.4 VDC - 78.18 watts ECT 4 hr 30 min

The Lithium charger stayed at 15.48 amps going in the whole charge time and only lowered the amps to @ 2 from 104 - 105% SOC.

During an early test the WFCO started out @ 6 amps charging and the closer to 90-95%, lowered the amps to 2 the rest of the way to near 100%. Probably not in Lithium mode.

For S&G's - WFCO Off - Lithium Off
Truck plugged in, engine idling, SOC 75%
-1.95 amps - 13.3 VDC - -25.97 watts ECT 40 hr 30 min

Hardly no load coming off the battery starting at -3.31 amps for RV lights and such but still at idle the truck was not charging the battery. I don't know exactly how our RAM charging systems works, or how RAM lets it work, for sure, with it's 220 amp alternator. It may not provide much at all when idling. But what happens at 65 mph towing, I don't know.

Now I did fully charge the battery with the Lithium charger and it took about the estimated charge time and brought the battery back to 105%.
Then I turned Off the Lithium charger, Turned On the WFCO charger to maintain the charge, and the battery was reporting minus amperage charge, like the WFCO charger was not outputting anything, which puzzled me a little.

After a few minutes when the battery got down to @ 102% SOC, the WFCO kicked in and the battery app was reporting
0 amps - 14.38VDC - 0 watts or in other words maintaining the status quo. No power going in or coming out of the battery.

Just some interesting test results, I thought.............

 

[Butcher]

In theory, you can't be above 100%. You need to reset the learned value.

 

[triplethreat]

In theory, you can't be above 100%. You need to reset the learned value.

In theory, you are correct......but....(and there's always a but), in the case of my DIY batteries, rated at 302AH on the cells, after I completed the build and top balance, then charged them up to 100% SOC, I did a battery load test. I set my Victron shunt to 100% SOC then started the test. I used a 200W 12VDC electric heat strip with a fan blowing on it to keep it trying to pull the max amount of current, which was right around 18.xx amps. I also set my LV cutoff setpoint in the BMS to 2.55V per cell and then let it eat. I shut everything down when I was showing just above the 2.55V/per cell and my AH total was 306. BTW, I didn't bother changing the 100% SOC setting in the Victron after I charged everything back up, but I did change the BMS Low Voltage cutoff back up to 2.60. I normally never let the battery get that low before charging, but it was a good way to make sure that the cells that I bought were in fact good cells and could provide the rated AH that they were advertised for.

 

[Butcher]

I think of the SOC like a gas gauge.

When is there a way you can ever get 102% of full? If you can, then the gauge is not set right. Does it matter? To me it does. Give me facts so I can make decisions.

My BMS settings are similar to yours. I don't charge them to full capacity nor do I go to 2.5v. Does it really matter? Makes me feel good and that is all I care about.

If there is a situation that I need a bit more capacity, then I know I can change the settings and get me out of a tight spot. Can't say I will ever be there.

 

[Steven@147]

I am new to the Lithium battery game and I'll admit there is still a lot I don't fully understand, but I am sneaking up on getting familiar with it. Then again, for me, I am not too obsessed with getting it totally figured out. As long as it does what I want it to do and lasts a long time, I'm ok with that.

Also there are a few things displayed on the Bluetooth battery app that I don't know what it means. I wish there was a tutorial on this battery's specific app and version. I've looked for some explanations and looked at few YouTube's but none I can find for my battery's specific app and version. I'll keep looking and I'll get it somewhat figured out.

Here I am a past retired electronics technician (going back as far as the early 80s) not fully understanding everything Lithium, can you see me trying to explain this to the Wife and how it benefits us? Volts, amps, watts, SOC, might as well be speaking another language!

 

[Butcher]

It's a lot to learn and understand.

I get electronics and on a basic level, understand it well. What always got me confused in the beginning was comparing the lithium technology with the lead acid. For me, it best to forget everything you know about lead acid batteries and start new. Comparing just confuses things.

You don't need to know that much but one benefit of knowing is that you can figure things out if something goes wrong.

Someday, the light will turn on bright and all of this will make sense. Even if someone just put in a LifePo4 battery in their rig and did nothing else, I do believe there would be a huge benefit.

I think the most important thing is you cannot charge the battery less than 32F. If you do not buy a battery that prevents that, you should rethink that decision.

 

[triplethreat]

I think of the SOC like a gas gauge.

When is there a way you can ever get 102% of full? If you can, then the gauge is not set right. Does it matter? To me it does. Give me facts so I can make decisions.

My BMS settings are similar to yours. I don't charge them to full capacity nor do I go to 2.5v. Does it really matter? Makes me feel good and that is all I care about.

If there is a situation that I need a bit more capacity, then I know I can change the settings and get me out of a tight spot. Can't say I will ever be there.

SOC and a gas gauge comparison are similar, but what I am talking about is the "advertised" ampacity of the cells that make up the battery. They are advertised as 302AH. On my battery load capacity test I ended up with 306AH. That test was done to push the battery to it's limits to make sure that the advertised capacity vs. the "real" or actual capacity was at least as much as advertised....and it turned out that it was. There was actually bit more ampacity in the battery, but that would involve setting the lower cutoff voltage in the BMS down to exactly 2.5V per cell....instead of the 2.55 that I set the BMS at for the test. It probably has no real world value to be able to say "I've got a 306AH battery vs. a 302AH battery, but again, that wasn't the purpose of the test.

Buying cells and building a battery, when you source your cells from a Chinese manufacturer can be sketchy at times. They know that they can say whatever they want about the cells.....xx amount of capacity, new cells, Grade A cells, etc, etc, but the only true way to make sure that you got what you paid for is to the do the load test and verify. EVE brand cells are kind of well know for making a good cell and being true to their advertising numbers. In my case, they were spot on and provided at least what they advertised....and just a bit more. I've read where guys bought cells from overseas and they were advertised as XX AH cells and they finally get them after a slow boat from China ride over to the states and then they do their build and the battery comes up some percent short of what the cell was advertised as. Highly unlikely you will get a response from them, and highly unlikely that even if you do, they will make it right....and most guys just get mad about it, go on a forum and bad mouth the company, and eventually realize that they are going nowhere with their legitimate complain and go ahead and just live with the cells/battery that is/was probably a "seconds" cells being sold as new.

 

[gchalifoux]

Just received 2 new litime 12v 100ah group 24 batteries. Basically out of the box these have little to no charge. Instructions in the box says to bench charge individually to approx. 13.33v as step 1.
Step 2 is for voltage balancing which says install in parallel together and leave standing for 12 to 24 hours BEFORE connecting to the rv load.

Problem is my ctek mus 4.3 charger does not appear to support lithium batteries. Had to order a new litime lithium battery charger...although other brands would I assume work as well.

Is bench charging REALLY the best or smartest way to charge need lithium batteries?? Not questioning the manufacturer, just curious...I assume the voltage balancing is required to make sure I will get 100ah from each. Or total 200ah....

 

[Butcher]

People seem to forget you cannot compare anything with a lead acid battery.

The lithium battery has a BMS. This control module regulates the charging of the lithium batteries. It will only allow the good electrons to go in and out of the battery. Would a standard cheap 12V battery charger charge the lithium battery? Sure it would. Fully charge? Probably not. Over charge? It can't, that is the BMS's job.

How good is the BMS in your Lithium battery? I don't know, but I do know on my battery, it's known to be good. One of the benefits of a DIY battery.

 

[Steven@147]

Just received 2 new litime 12v 100ah group 24 batteries. Basically out of the box these have little to no charge. Instructions in the box says to bench charge individually to approx. 13.33v as step 1.
Step 2 is for voltage balancing which says install in parallel together and leave standing for 12 to 24 hours BEFORE connecting to the rv load.

Problem is my ctek mus 4.3 charger does not appear to support lithium batteries. Had to order a new litime lithium battery charger...although other brands would I assume work as well.

Is bench charging REALLY the best or smartest way to charge need lithium batteries?? Not questioning the manufacturer, just curious...I assume the voltage balancing is required to make sure I will get 100ah from each. Or total 200ah....

When I received my single Lithium battery it was 50% charged. I shut down the AC power to the RV, turned the battery disconnect switch on, then went ahead and installed the battery in the RV. Then turned on the AC power to the rig and then turned off the battery disconnect switch. Our converter/charger then started to charge the battery.

The way I look at it, in my simple mind
I think what they mean by "placing the battery in service" is pulling power out of the battery, not putting a charge in. So in effect I bench charged the battery installed in the RV.
Now my single lithium battery is just a box containing 4 small batteries. The BMS's job is to ensure each cell within the battery box is balanced when charging or is charged. Each one reads 3.41. When one cell reads lower than the others, or there is unbalance between the four cells, the BMS applies more charge power to the low cell bring it back up to match the others. Each reading the same as in this case each reading 3.41.

Connecting just two lithium batteries together in parallel. Charge power coming from whatever source, converter/charger or inverter charger or external lithium charger, goes to the batteries. The 1 foot short cables connecting the batteries together in effect kind of a bus bar, albeit the positive and negative together total 2 foot long. So each battery should receive about the same charge power. Then the BMS in each battery box should keep the 4 cells in each battery box in balance. In my scenario each of the four cells in a battery box reading 3.41.

Now connecting 3,4 batteries in parallel, using cables, maybe 6 total, may not be the way to go. The collection of these 6 cables together now induces somewhat of an imbalance by each battery receiving a little different charge power in effect the sudo buss bar cabling is now 6 feet long each positive and negative.. The first battery in the cable chain will see the most charge power. This makes it harder for each battery box with the fours cells within each box all keeping in balance.
Now one needs to incorporate short buss bars, maybe 6 inches long, one positive, one negative. Then connect each battery box to the buss bars with as short a cable as possible or at least close to the same length. Now each battery receives the same charge power potential because they all are connected to the same common charge power source.

At least that is the way I look at it, but I'm no expert and maybe all wet.

 

[gchalifoux]

HELP!!!

Hey folks, just completed the final connections to my dual 100ah parallel wired LiTime batteries. My final connection is pos to battery 1, and neg to battery 2. The solar controller sees the battery(s) , the LiTime app is configured to have the batteries configured as 1 dual battery, but the rig has no power. ? I don't want to assume anything but hoping someone might have a tip.

**update** - the LiTime app used to configure the "battery system", I chose 2 batteries under the P for parallel configuration. However on the "edit battery system" screen it seems to automatically set it to 1S2P, which then throws a message that says "modification is not currently supported"....I'm thinking this should read 2P only?? and not 1S2P...anyone??

things I should double check?
thanks/Gary

 

[gchalifoux]

HELP!!!

Hey folks, just completed the final connections to my dual 100ah parallel wired LiTime batteries. My final connection is pos to battery 1, and neg to battery 2. The solar controller sees the battery(s) , the LiTime app is configured to have the batteries configured as 1 dual battery, but the rig has no power. ? I don't want to assume anything but hoping someone might have a tip.

**update** - the LiTime app used to configure the "battery system", I chose 2 batteries under the P for parallel configuration. However on the "edit battery system" screen it seems to automatically set it to 1S2P, which then throws a message that says "modification is not currently supported"....I'm thinking this should read 2P only?? and not 1S2P...anyone??

things I should double check?
thanks/Gary

Now I am hearing that my converter might be the issue? SOmething about switching it from lead/acid to lithium??
folks? need some input...thanks

 

[gchalifoux]

Now I am hearing that my converter might be the issue? SOmething about switching it from lead/acid to lithium??
folks? need some input...thanks

Verified the actual model# of my converter is 9855-AD which according to the manufacturers website is fully auto-detect. The video on their website did say something about 1 complete charging cycle?? weird. Batteries are brand new 100% charged parallel wired. MPPT controller is set for lithium but still the controller has the red led indicating either fault or no battery connected. Everything in the LiTime app setup SEEMS correct. Waiting to hear back from the WFCO converter tech support group. I also disconnected the MPPT controller for 30 seconds and reconnected to no avail.

 

[SolarPoweredRV]

Verified the actual model# of my converter is 9855-AD which according to the manufacturers website is fully auto-detect. The video on their website did say something about 1 complete charging cycle?? weird. Batteries are brand new 100% charged parallel wired. MPPT controller is set for lithium but still the controller has the red led indicating either fault or no battery connected. Everything in the LiTime app setup SEEMS correct. Waiting to hear back from the WFCO converter tech support group. I also disconnected the MPPT controller for 30 seconds and reconnected to no avail.

Can you post pics of your battery wiring and where the wires that come off the battery go to?

This would be helpful, rather than us just taking a stab in the dark.

With that said, here is my "stab in the dark" solution...

If you refer to the picture posted by Steven147 (above), this is how your batteries should be wired into your coach, with your coach being the "application" (or load) in the picture. Additionally, you have indicated that you have attached one "load" wire to the positive post on the first battery and the second "load" wire to the negative post on the second battery. This is a better way to connect two batteries than is shown in the above picture.

Please ensure that you have, in fact, connected the two batteries with positive to positive cables and that the second load wire is connected to the negative post on the second battery.

Additionally, you want to ensure that your disconnect switch is in the "closed" position (the red key cannot be removed).

Please check these things and let us know what happens.

 

[gchalifoux]

Can you post pics of your battery wiring and where the wires that come off the battery go to?

This would be helpful, rather than us just taking a stab in the dark.

With that said, here is my "stab in the dark" solution...

If you refer to the picture posted by Steven147 (above), this is how your batteries should be wired into your coach, with your coach being the "application" (or load) in the picture. Additionally, you have indicated that you have attached one "load" wire to the positive post on the first battery and the second "load" wire to the negative post on the second battery. This is a better way to connect two batteries than is shown in the above picture.

Please ensure that you have, in fact, connected the two batteries with positive to positive cables and that the second load wire is connected to the negative post on the second battery.

Additionally, you want to ensure that your disconnect switch is in the "closed" position (the red key cannot be removed).

Please check these things and let us know what happens.

I think I solved the issue. It dawned on me that in order for the converter to sense or determine what type of battery was connected it needs power???? so I plugged the camper into shore power and it looks like everything is now working properly. Got to test off grid to be sure but I "think" I might be good to go....
g

 

[kb0zke]

Yes, the converter turns 120 VAC into 12 VDC, so if you want to charge the batteries there must be 120 VAC coming in. Yes, many of us have made the same mistake. Unless you paid someone to find the problem, you solved the problem without any cost. I can live with that type of problem.