Lithium Battery question ...

TimNJ96TA · 04-19-2023, 08:19 AM

I tried to search and nothing really to answer my question, and if this isn't the correct subforum then I apologize ...

My new Bullet has the dragonfly 200 solar with two heated 100ah lithium batteries installed. When not in use, the unit is in the driveway plugged into the house. I keep my converter on since the main fridge is 12v only, but I think its just the standard WFCO and not a 3 or 4 stage, so I'm afraid it will cook the batteries over time from constantly charging.

I do still need to connect to the solar controller and make sure its set for lithium. My main question is what is the recommended way to keep them at idle to get the most life out of them?

1) Let it sit with everything on and hope for the best until I order a smarter converter

2) Disconnect the solar and batteries and let them sit idle and let the converter do the work

3) Turn off the converter and le the solar recharge the batteries during the day?

bobbecky · 04-19-2023, 08:28 AM

Your converter is already a smart converter, but when in lithium mode, there will not be any need to do the cycles that are needed for a lead acid battery, no sulfation issues. If you check your converter for the model number, you should have the manual or can get it online and that will give you what it does to your batteries when plugged in to shore power. Being plugged in all the time is no different than if you lived in the rig full time, you would be connected to shore power all the time. The system should be designed to protect the batteries.

Max23 · 04-19-2023, 10:21 AM

I have the exact same batteries in mine with the 400i solar package. Mine sits in the driveway not plugged in as it is not needed. The refrigerator is stocked and cold as we have been using it a lot, and the solar keeps it charged just fine. I did have it plugged in all winter but I wasn't running anything and had the batteries out of it in the house. I just kept it plugged in so if I needed to go in for some reason I'd have lights or could run the furnace if I wanted. To keep it plugged in all the time is no problem at all for it. The charge controller will not let them overcharge, they will not cook. (barring something going bad I guess). But you can do either, as much as I have been out I just don't bother plugging it in all the time at home when the solar does more than an efficient job of recharging during the day for whatever is used overnight. Just Thats been my experience anyway.

firestation12 · 04-19-2023, 11:20 AM

Quote:

Originally Posted by Max23

I have the exact same batteries in mine with the 400i solar package. Mine sits in the driveway not plugged in as it is not needed. The refrigerator is stocked and cold as we have been using it a lot, and the solar keeps it charged just fine. I did have it plugged in all winter but I wasn't running anything and had the batteries out of it in the house. I just kept it plugged in so if I needed to go in for some reason I'd have lights or could run the furnace if I wanted. To keep it plugged in all the time is no problem at all for it. The charge controller will not let them overcharge, they will not cook. (barring something going bad I guess). But you can do either, as much as I have been out I just don't bother plugging it in all the time at home when the solar does more than an efficient job of recharging during the day for whatever is used overnight. Just Thats been my experience anyway.

You lithium battery likely has a BMS which will prevent the battery from over and undercharge by disconnecting the negative pole. It should also prevent charging if the internal temp dips below 32 degrees F

Max23 · 04-19-2023, 02:24 PM

Yes, they don't like cold, that's why they are heated. Also need brought inside during the winter.

Stircrazy · 04-27-2023, 05:37 AM

it depends how long you are leaving it in the driveway for. They should not be kept at full power when they are not used to be honest. When I come home, I turn off the solar the night before leaving the campground so what I used over night runs me down to about 70% capacity then I flip off the battery switch if I am going to plug it in because the fridge is running. If it is winter, I just leave it black. storing at full capacity or long times of running at charge to them could shorten the life span of the battery, by how much who knows, but all the manufactures recommend storing the batteries at just above 50% capacity. I shoot for 50 to 70%.

If you really want to know, there should be a little booklet that came with your system. it will tell you how you should do everything, but if it were me, I would shut off your batteries and solar and just run off shore power if you want to just run the fridge.

bobbecky · 04-27-2023, 12:10 PM

Not all lithium batteries need to be stored at 50 or 70%. This link is from Battle Born, and they say to store them at full charge. You have to scroll down a ways to the section where it talks about storing for the winter. https://battlebornbatteries.com/will...teries-freeze/

Steve/ · 04-27-2023, 03:24 PM

There is so much misleading information out there it hard to tell what is what. All most all of my knowledge come from electric bike and what I have read on line. I am going on my 4 season. I pull the battery in each winter (Denver) full charge for the first 2 winters. then found out it is suppose to be 80 % charge, 3rd season it was at a full charge again, I have read bike battery are only good for 3 years, it is getting a little weak but working.
1 you can use the battery in cold weather, they just can not be charged.
2 they should not be left fully charged, see above, this is not true for all battery.
3 different battery builder have different idea what a cycle is for life of battery.
4 Car battery use what they call an "A" battery and the rest are "B" battery that did not make the grade. and are not as good and life may be shorter. Again maybe some make it to RV battery.
5 Some battery have BMS in them that protect them.
6 Not sure you are going to get the best advice here, you need to find out who make your battery and get the specification and care and feeding of your battery from them.
7 I hope I am not adding to the miss information on the net.

Stircrazy · 04-28-2023, 05:24 AM

Quote:

Originally Posted by bobbecky

Not all lithium batteries need to be stored at 50 or 70%. This link is from Battle Born, and they say to store them at full charge. You have to scroll down a ways to the section where it talks about storing for the winter. https://battlebornbatteries.com/will...teries-freeze/

actually, like I said, they don't need to be in that 50 to 70% range but if they are stored full it will degrade their life span, and 50 to 70% is what the cell manufacturers recommend. Battleborn is not a manufacturer. They get off the shelf parts and assemble them, they are nothing more than an assembling company.

what battle born has done is said it is not a concern to us and it is an acceptable reduction that it will be outside the warranty period anyways, so they don't care and make it sound easier.

You can't change the chemistry, although LifePO4 is a lot more forgiving than other Li chemistry-based batteries it still has a few quirks.

what I am saying is that if you're going to spend the already inflated price of a battle born, would you want to keep them in tip top shape as long as you can. that would be setting them to only use between 10% and 90% range state of charge (if you can) and long-term storing at a partial charge state and so on. Little things like this can almost double the cycle life.

Stircrazy · 04-28-2023, 05:46 AM

Quote:

Originally Posted by Steve/

There is so much misleading information out there it hard to tell what is what. All most all of my knowledge come from electric bike and what I have read on line. I am going on my 4 season. I pull the battery in each winter (Denver) full charge for the first 2 winters. then found out it is suppose to be 80 % charge, 3rd season it was at a full charge again, I have read bike battery are only good for 3 years, it is getting a little weak but working.

what chemistry is your bike battery? is it LiFePO4?

Quote:

Originally Posted by Steve/

1 you can use the battery in cold weather, they just can not be charged.

weather has not much to do with it, it is the temp of the battery its self. generally a LiFePO4 can be discharged down to -20C but shouldn't be charged much below 0C. there are some manufacturers that claim -5C or -2C but 0C is a good base

Quote:

Originally Posted by Steve/

2 they should not be left fully charged, see above, this is not true for all battery.

it is true for all LiFePO4 based batteries that we are talking about. The issue is people may or may not ever see the effects of leaving it full over the winter. it is most likely a small degradation in performance over many years, so we might be talking a 17 year life span instead of 20 years... is that really a big deal, and its up to each person to decide for themselves. I am still looking for info on how much that affects the cycle life, my next step is to email the manufacture of the cells I use to build my own battery

Quote:

Originally Posted by Steve/

3 different battery builder have different idea what a cycle is for life of battery.

see above these are not battery builders they are battery assemblers. And when they make a product one of the considerations is the warranty. so sometimes you see stuff that is strict on what you should and shouldn't do. this also depends on the BMS they chose, the grade of cells and the brand of cells (they are all slightly different)

Quote:

Originally Posted by Steve/

4 Car battery use what they call an "A" battery and the rest are "B" battery that did not make the grade. and are not as good and life may be shorter. Again maybe some make it to RV battery.

Im not sure how this is relating but there are a grade and B grade in LFP also, nothing to do with cars and rv though. in old lead acid batteries A cells were ones that looked perfect and tested higher than there rating, B cells were either blemished or tested under the intended rating. kind of the same with LiFePO4 but there were a lot of unscrupulous companies making batteries with B cells which in all fairness could have tested fine but looked bad or maybe they were used and sold as B cells. now EVE is specifically marking their B batteries, so it is known they are not A grade. You can get some significant savings buying B grade (I didn't myself) but if they test fine in their capacity and the price is right.....

Quote:

Originally Posted by Steve/

5 Some battery have BMS in them that protect them.

All multi cell LiFePO4 where you charge and discharge as a group will have a BMS. This is the most varied thing between assorted brands and even the same assembler hanging BMS units based on what they can get at the time. It is also probably the most important thing to know if you're going to put LiFePO4 batteries in series or parallel as if the BMS units are non-compatible it won't work.

Quote:

Originally Posted by Steve/

6 Not sure you are going to get the best advice here, you need to find out who make your battery and get the specification and care and feeding of your battery from them.

That's the problem, one assembler says one thing another says another which leads to confusion. I don't see a lot of stuff on this forum aside from battle born told me this or that or (insert assembler name) told me that so it must be true. I have seen others on here that seem to know what they're talking about but most of what I see on this forum is pretty basic as it is a brand specific forum.

Quote:

Originally Posted by Steve/

7 I hope I am not adding to the miss information on the net.

oh keep hoping, hopefully I gave you some info you might find useful haha

Steve/ · 04-28-2023, 06:43 AM

The bikes has 48V lithium ion battery, no idea what that is.
The statement about the "A" type battery came from an article about battery supply, that the auto indust is taking all the top level battery.
I think your post add to my, Thanks

smc00921 · 04-28-2023, 07:55 AM

We live in northern Michigan where the days can get well below 20 degrees. With leave our unit plugged into a 20 amp while leaving the 400i system on.

On the road we put the heat triggers on everything (batteries and tanks) with have no issues at all.

10 year warranty - get camping!

TimNJ96TA · 04-28-2023, 09:58 AM

Thanks for the replies.

I did go and connect to the charge controller on the Victron app and adjusted the settings to what the manual said is recommended for lithium. Equalization was on so I turned that off along with the temperature compensation. Then I set the absorption and float to the correct voltages.

Stircrazy · 04-29-2023, 05:39 AM

Quote:

Originally Posted by Steve/

The bikes has 48V lithium ion battery, no idea what that is.
The statement about the "A" type battery came from an article about battery supply, that the auto indust is taking all the top level battery.
I think your post add to my, Thanks

ya I don't think so much in prismatic cells, yet.... typically, tesla was using cylindrical cells like what battle born and a few others use, but recently they have been changing their new Chinese model to prismatic cells. it will be interesting to see what the new automotive battery plant VW is opening in Canada will produce. hopefully, they will make a surplus which can be sold locally for people like us.

Stircrazy · 04-29-2023, 05:40 AM

Quote:

Originally Posted by TimNJ96TA

Thanks for the replies.

I did go and connect to the charge controller on the Victron app and adjusted the settings to what the manual said is recommended for lithium. Equalization was on so I turned that off along with the temperature compensation. Then I set the absorption and float to the correct voltages.

which values did they recommend on that one.

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