KS2 Li-ion batteries and alternatives?

[booster]

Well shoot I forgot to say amongst all this babble that the BMS have High and Low temp shut down and will keep these warnings for you to see when you open the app to look at them through Bluetooth.

What is the high temp shutdown set at? You would also want to know the temp even if charging as high temp is bad for the batteries even if not charging. Low temp cutoff for charging isn't that way as discharge is OK colder. Of course this also brings up the perpetual question of if it is advisable to use the BMS in daily use control instead of separate controls. I chose to setup so, hopefully, the BMS will never need to shut off the batteries, unless something fails.

 

[D&C ERV2]

I have attached some screen shots from my App to show the temps settings and the log that keeps track of the BMS functions. While I had the App open, I changed the High temp to the lowest it would go 113. Thank you for joining the conversation. While I have never seen a temp over 95, I will be monitoring this much closer and putting more priority on getting the Bluetooth function to work while sitting in the driver seat. I completely agree that The BMS should be a failsafe and not the norm.

 

[Dadi]

maybe i'm out of context here. i just bought a 2024 roadtrek chase 50 (used) with no warranty and i am struggle to get any help from KS2 customer service about how to get a view/tool/app that can show the status of the battery as well as the whole system. the current solution that Roadtrek has is the firefly which shows you almost nothing. it is just to show how much the battery has but no indications if charging from alternator/solar/shore power yada yada yada like any base battery system should have. if any of you have some suggestions for me i'll be happy to hear. if i will solve it somehow i will be happy to share.

 

[D&C ERV2]

I looked up your unit on the web and Firefly to make myself a bit more knowledgeable and have some questions. Does your unit have Firefly currently or is that a suggested add from RT? What model monitor do you have? My unit is 2018 and only has voltage at the battery disconnect remote panel. I added epever MT-50 monitors for my solar charge controller's to be able to monitor solar input and they actually show more than that. I have been considering adding a smart shunt to the AGM under the hood to be able to monitor the UHG and the battery SOC. The APP for my Lithium's works great for Monitoring them via Bluetooth. Monitoring all systems through one screen would be nice but more expensive and more work. From what I saw on the Firefly web site some of these monitors may accomplish most of the this.

 

[booster]

I looked up your unit on the web and Firefly to make myself a bit more knowledgeable and have some questions. Does your unit have Firefly currently or is that a suggested add from RT? What model monitor do you have? My unit is 2018 and only has voltage at the battery disconnect remote panel. I added epever MT-50 monitors for my solar charge controller's to be able to monitor solar input and they actually show more than that. I have been considering adding a smart shunt to the AGM under the hood to be able to monitor the UHG and the battery SOC. The APP for my Lithium's works great for Monitoring them via Bluetooth. Monitoring all systems through one screen would be nice but more expensive and more work. From what I saw on the Firefly web site some of these monitors may accomplish most of the this.

Is the the AGM under the hood the "kicker" battery for the KS2 batteries and separate from the starting batteries?


If so, it probably will never get to full if the current KS2 charging recommendations are used, . It would probably never get past about 70-80%. This can be allowed for in the programming of the battery monitor on it, but will still affect accuracy with no good calibration point to reset it to a known amount (normally 100%). It would still be useful, but a simple voltmeter could probably tell you all you really need to know as it only needs the be charged enough to initiate the charging circuits and to get the lithium batteries activated.

 

[D&C ERV2]

My unit has a separate starting battery and alternator. The AGM under hood would be considered the kicker but I no longer need it for that purpose because of my rebuild. I can use it separately if needed say for cold weather charging or batteries to hot but haven't found a need for that yet. Thats why I think it may be a good idea to have both battery types on board and put the biggest AGM under the hood that I can find. I have been and still looking at alternative charging for both types of batteries to maintain optimal charge. DC to DC chargers would work but more expense and more work. There are other systems available Like Wake Speed and Balmar has an upgraded Voltage Regulator. I have also been looking at a Bank manager that I found a boat owner is selling that will take care of the mixed battery types.

 

[booster]

My unit has a separate starting battery and alternator. The AGM under hood would be considered the kicker but I no longer need it for that purpose because of my rebuild. I can use it separately if needed say for cold weather charging or batteries to hot but haven't found a need for that yet. Thats why I think it may be a good idea to have both battery types on board and put the biggest AGM under the hood that I can find. I have been and still looking at alternative charging for both types of batteries to maintain optimal charge. DC to DC chargers would work but more expense and more work. There are other systems available Like Wake Speed and Balmar has an upgraded Voltage Regulator. I have also been looking at a Bank manager that I found a boat owner is selling that will take care of the mixed battery types.

An AGM just sitting under the hood and unused or charged probably won't last very well unless routinely charged or on a tender. Depending on where it is under the hood and the temperature in that area, it is very possible that there will be enough high temps to shorted it's life as AGMs don't like high temps the many underhood areas get these days.


In our system I chose to not use a DC to DC charger for a lot of reasons.


I did put our second alternator (280amps) on a Wakespeed remote regulator as the Balmar is not very capable unit if you are picky on charge control accuracy and consistency, plus settings are limited.


I have our Wakespeed working reliably at this point, but the final charge control to charge to only 80% full is controlled by a standalone, dedicated Victron battery monitor. The Wakespeed is not as capable as they would lead you to believe, but does some stuff well, and does have some warts.


There is a new remote regulator that is very similar to the Wakespeed and their claim is that they have addressed the issues that exist with Wakespeeds. I have not had a chance to try one to this point. There literature is very light in detail of how things are handled and when I contacted them, they were not responsive when I asked specific technical questions. The regulator is Arco Zeus.

 

[GeorgeRad]

An AGM just sitting under the hood and unused or charged probably won't last very well unless routinely charged or on a tender. Depending on where it is under the hood and the temperature in that area, it is very possible that there will be enough high temps to shorted it's life as AGMs don't like high temps the many underhood areas get these days.
.........................

I have two AGM batteries; one under the hood (MB Sprinter 2013) and one in the rear-mid driver side of the van. The first set of Fullriver AGMs lasted about 11 years. I recently replaced the old, still functioning batteries with a new identical set. The under-hood AGM was very well insulated but I am certain was operating at higher temperatures than the rear one.

 

[Dadi]

I looked up your unit on the web and Firefly to make myself a bit more knowledgeable and have some questions. Does your unit have Firefly currently or is that a suggested add from RT?

>>>>Answer by Dadi - i have it already in my RV. I do not have to buy it.

What model monitor do you have? My unit is 2018 and only has voltage at the battery disconnect remote panel.
>>>>Answer by Dadi - i tried to find the monitor version with no success. i believe it is the newest as the Rv is not even one year old.

I added epever MT-50 monitors for my solar charge controller's to be able to monitor solar input and they actually show more than that.

>>>>Answer by Dadi - i did the same but it only gives me a view of the total volt from both batteries and if the solar is charging yes or no. see attached image

I have been considering adding a smart shunt to the AGM under the hood to be able to monitor the UHG and the battery SOC. The APP for my Lithium's works great for Monitoring them via Bluetooth. Monitoring all systems through one screen would be nice but more expensive and more work. From what I saw on the Firefly web site some of these monitors may accomplish most of the this.

>>>>Answer by Dadi -thank you . i am new to the RV world so not sure what is UHG and SOC. I have an App that KS2 gave me but i guess i am missing some kind of a dongle that can send the KS2 batteries data to the app. What app are you using and how do you get the data from the KS2 batteries. I am OK not to have it all in one screen. having the info on my phone in a few different apps is more than i can aske for. thank you for your help

 

[D&C ERV2]

SOC=State of Charge. The Bluetooth dongle and app will give you this. If you purchase the dongle, can you add it to the system without opening the case?

UHG=Under Hood Generator (Alternator Used for House System Charging)

I am using an SFK app that won't do you any good without rebuilding your batteries with their BMS.

So apparently the SOC won't show up on your Firefly screen?

 

[Dadi]

SOC=State of Charge. The Bluetooth dongle and app will give you this. If you purchase the dongle, can you add it to the system without opening the case?

UHG=Under Hood Generator (Alternator Used for House System Charging)

I am using an SFK app that won't do you any good without rebuilding your batteries with their BMS.

So apparently the SOC won't show up on your Firefly screen?

thank you for your prompt answer.

i learned that UHG is not a real generator but basically a 280 walt alternator.

your SFK app is connected to your KS2 batteries ? when i contacted KS2 they offered me to by their BMS for $450 or so and on top of that i have to go to a shop for installation. At the end it will give me ONLY the status of the batteries (% level) and no more. so i am not sure i will do it. i wonder how the firefly gets the info about the batteries ? and yes, the Firefly currently shows only the total volt of both batteries (showing only one battery image, not two) and no SOC.

 

[D&C ERV2]

I have rebuilt my batteries using SFK as a resource for parts and information. One of my batteries is built with cells from a KS2 battery but that's all I used besides the case. If that's all you have for monitoring and you need to rebuild to fix the problem, you should look under photos I just created an album call KS2 Battery Rebuild. Those relays in the KS2 are a source for problems and not being able to monitor cell balance doesn't work for lithium.

 

[D&C ERV2]

I have uploaded some additional pics to photo album KS2 Battery rebuild that show some screen shots of the monitoring from the app. The only issue the app has that for me really is a non-issue is that you can't tell it your battery is 200AH. The lowest setting is 240 so you will see in the pic that it thinks the battery has more capacity than it really has. The BMS in both batteries work together during charge and discharge to stay in balance with each other.

 

[Stan-in-Ohio]

I have a 2018 Road Trek RS Adventurous and rebuilt both of my KS2 batteries using the under-chassis boxes. As for what caused our problems, I think that lithium has come a long way in a short period of time and in the beginning the BMS was not as reliable as they are now along with how they were wired and set to charge (My KS2 batteries were wired wrong and the Balmar Charge settings as Recommended by KS2 now are way different than my unit was set and I think these 2 things were a big contributor to the failure of the relays and cell.) As far as my batteries I found one dead cell out of the 8 and decided to rebuild the 200AH using old cells and build a new one using 280AH cells. After a lot of YouTube videos and research I decided to use Sun Fun Kits for my new BMS and cells along with active balancers, heat pads, some cable, lugs and their mounting risers. I did not use their box or prebuilt battery. I am very happy with how my system works now and strongly recommend SFK if you're looking to save money and capable of doing the work. I have less than $2000.00 dollars in both my batteries including other tools and supplies needed to complete the build. I have pics attached that will show before and after. New at this forum stuff but willing to help as much as possible.

I Like what you’ve done to your KS2 battery packs. I have had troubles or concerns about my 2020 Roadtrek Zion Slumber KS2 system from Day one.
I have the FireFly control screen and everytime I contact Roadtrek, they refer me back to the older style control system with Push Buttons. I could go on & on but it’s useless. My Roadtrek Dealer Service department was/is useless as well. So I have been Winging it on my own. Now I am adding a Solar panel and asked them (Roadtrek) about parameters, and as you might of guessed, They sent me a flyer with the old pushbutton System. And then a KS2 flyer with a list of parameters a mile long. Really horrible Horrible customer support. I love the van and its layout, but getting anything fixed has been a nightmare. So, If I want to replace my pack or rebuild I would appreciate any help or suggestions. BMS’s for Lithium packs are Greek to me, but I did build my own Electric car once. And it worked well for a couple years. But that was back in 2006. Things have changed. Thanks in advance

Stan in Ohio

 

[D&C ERV2]

I Like what you’ve done to your KS2 battery packs. I have had troubles or concerns about my 2020 Roadtrek Zion Slumber KS2 system from Day one.
I have the FireFly control screen and everytime I contact Roadtrek, they refer me back to the older style control system with Push Buttons. I could go on & on but it’s useless. My Roadtrek Dealer Service department was/is useless as well. So I have been Winging it on my own. Now I am adding a Solar panel and asked them (Roadtrek) about parameters, and as you might of guessed, They sent me a flyer with the old pushbutton System. And then a KS2 flyer with a list of parameters a mile long. Really horrible Horrible customer support. I love the van and its layout, but getting anything fixed has been a nightmare. So, If I want to replace my pack or rebuild I would appreciate any help or suggestions. BMS’s for Lithium packs are Greek to me, but I did build my own Electric car once. And it worked well for a couple years. But that was back in 2006. Things have changed. Thanks in advance

Stan in Ohio

Are your batteries in a case? I assume they are and you could disassemble them to add bms and other parts needed to get better monitoring and control. You may find that your cells are still good and all you have to do is remove the KS2 parts and rebuild. If your case is metal I would consider using the SFK kit without cells.To add a solar panel you will need a controller if your unit doesn’t already have one. SFK has a channel you can view for help in understanding what you need to know. There are other channels that I subscribe to as well that have information on solar. I have been private messaging with another member and would be happy to do the same for you if you would like.

 

[chowdog]

With help from D&C, I replaced my KS2 batteries with the SFK kits. I managed to reuse the KS2/Ecotrek cables that are connected to the battery switches in the front and replaced them with the SFK switches and rs485-based monitors. I had to add a cat5 cable to complete the functionality of the monitors and the bluetooth control. Routing the new cables was the hardest part - had to dismantle quite a bit to accomplish that. Moved the bluetooth modules from the batteries inside the van as well.