KS2 Li-ion batteries and alternatives?

[S&S THOMAS]

I have a 2019 Roadtrek CS Adventurous with solar panels and four 200 Amp-hour (Ah) Li-ion house batteries, made by KS2 in Canada. Three of the batteries are the original L1 model and the 4th is an L2 model because I have already had to replace one of the original L1 batteries within 18 months of purchasing the rig, which we bought new in 2019. Two more of the L1 batteries have now died and I need to replace them. The last L1 battery may not be far behind.

KS2 batteries are extremely expensive compared to other brands that sell comparable Li-ion batteries (Ah & wattage ratings). The price I have been quoted here in Colorado is $3120 each (plus ~$500 shipping; plus ~$1000 installation), so I am looking at about $8k to replace these two batteries. I am wondering if anyone has figured out what it would take to replace all 4 batteries and adjust/modify the other components of the system so that everything works right. Any advice you can provide, being as specific as possible, would be much appreciated. Also, if you can suggest someone capable of performing the work for such a project here in Colorado or elsewhere I would be very grateful.

Thanks very much in advance, Steve

[GeorgeRa]

Originally Posted by S&S THOMAS

I have a 2019 Roadtrek CS Adventurous with solar panels and four 200 Amp-hour (Ah) Li-ion house batteries, made by KS2 in Canada. Three of the batteries are the original L1 model and the 4th is an L2 model because I have already had to replace one of the original L1 batteries within 18 months of purchasing the rig, which we bought new in 2019. Two more of the L1 batteries have now died and I need to replace them. The last L1 battery may not be far behind.

KS2 batteries are extremely expensive compared to other brands that sell comparable Li-ion batteries (Ah & wattage ratings). The price I have been quoted here in Colorado is $3120 each (plus ~$500 shipping; plus ~$1000 installation), so I am looking at about $8k to replace these two batteries. I am wondering if anyone has figured out what it would take to replace all 4 batteries and adjust/modify the other components of the system so that everything works right. Any advice you can provide, being as specific as possible, would be much appreciated. Also, if you can suggest someone capable of performing the work for such a project here in Colorado or elsewhere I would be very grateful.

Thanks very much in advance, Steve

I am not going to help you regarding Lithium batteries replacement being the owner of new AGM batteries replacing over 11-year-old ones but question such a short life of your lithium ones – what caused their fatal failures?

[@Michael]

Sounds like a can of worms. FWIW I found a link that might help, if you have the same or similar setup:

https://www.classbforum.com/forums/f...-diy-8976.html

[S&S THOMAS]

Unfortunately, I really have no idea regarding the cause(s) of these battery failures, but it does suggest a quality issue with the design of the battery, frankly. The last 3 winters, we have spent in southern California, so they haven't even been exposed very much to cold temps.

[S&S THOMAS]

Michael, thanks for your reply and the link to the prior post, which is an interesting similar situation. This is the kind of person I need to talk with, so I will try to contact him and see how things came out for him.

Steve

[booster]

Originally Posted by S&S THOMAS

Unfortunately, I really have no idea regarding the cause(s) of these battery failures, but it does suggest a quality issue with the design of the battery, frankly. The last 3 winters, we have spent in southern California, so they haven't even been exposed very much to cold temps.

I am certainly not an expert, or even a user, of the KS2 batteries but in general, most of the lithium cells are pretty similar from what I have read. This doesn't include the recent use of more of the "reconditioned" or sorted out less than stellar cells, though.


Roadtrek has had lots of failures, it appears, since the very beginning, so you have to be suspect of the system related to the lithium cells themselves. Without seeing in person how they control, charge, discharge, and protect the cells none of us will have any idea what is going on. What is interesting is that there really doesn't appear to be much in analysis of just what is bad in the Roadtrek system. That makes it possible that perhaps everything is substandard and contributing.



Roadtrek used quite a few "private label" non mainstream, components, in the systems they made in those periods, including the lithium packages, so that may be part of it. Failures of those parts has been pretty common. Do they allow to much charge percent, to fast discharges, to low SOC before shutdown, all are unknown to me at least.


Replacing the KS2 batteries is not really cost effective, it appears. It may be money ahead to find a reputable, maybe Victron installer for instance or equivalent, to design and install a complete, matched, time tested system. In the longer timeframe you probably would come out better from cost, hassle, and reliability standpoint.


Much of the knowledge and experience in this stuff seems to be with the marine tech systems and installers, and that almost guaranties higher costs, so be prepared.

[S&S THOMAS]

Booster,

Thanks for your thoughts and the suggestion about Victron. I will check into them as a possibility.

Steve

[mumkin]

Originally Posted by S&S THOMAS

Unfortunately, I really have no idea regarding the cause(s) of these battery failures, but it does suggest a quality issue with the design of the battery, frankly. The last 3 winters, we have spent in southern California, so they haven't even been exposed very much to cold temps.

The early batteries were problematic and have been improved quite a lot... but they seem to me to be insanely overpriced to get down here and install.

My suggestion is when you get to California next, head to Edge Vanworks east of San Francisco. He (Gordon) started out rescuing the orphan Hymers left behind by the bankruptcy and knows the Ecotrek systems well. I have heard that he is currently changing out lots of Roadtrek Promaster models from KS2 to more off-the-shelf reasonably priced less temperamental systems. I'd give him a call. Likely not cheap, but at least he knows what the heck he is doing.

https://edgevanworks.com/

There are not any outstanding Colorado options... maybe Van City? I think they are a RT dealer, but haven't heard much buzz on them over on our owner pages on FB.

[S&S THOMAS]

Mumkin, Thanks for the excellent suggestion! I will contact Gordon at Edge VanWorks and see what he can do for me. Livermore is a reasonable target from southern California this fall/winter.

Many thanks, Steve

[Moto vita]

If you search ecotrek free you will find lots of info about replacing ecotrek batteries which have been a nightmare for many owners.
Since you already have batteries inside your van I would look into putting new batteries in that location and eliminating your outside ecotreks., you may be able to fit close to the capacity of your 4 ecotreks in that space. Of course this will require a new wiring and control setup and you may end up replacing your inverter charger/charger too so it will be an expensive solution but you will be free of Ecotrek.
Durango RV repair has developed a method of rebuilding ecotrek batteries inside their boxes, you might call him.

[S&S THOMAS]

Moto Vita,
Thanks for your reply and the contact at Durango RV, which at least is in the same state as I am living.
I do not have batteries inside the RV; only 4 EcoTreks underneath in the rear of the Sprinter. There is really no space inside the RV where I could put these large batteries. I will contact Durango RV and see what they have to say, but I am also pursuing a complete battery replacement strategy with Edge VanWorks in Livermore, CA. Thanks again to Mumkin for that lead.

[S&S THOMAS]

Moto Vita,
Thanks also for the hint about "EcoTrek Free". Did not know about this faceBook group. I hadn't looked before I responded previously. Thanks again.

[Moto vita]

My mistake I thout on the 4 ecotrek system 2 of the batteries were inside the van. In that case I'd be more inclined to try to use the ecotrek boxes that you have.

[D&C ERV2]

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.

[@Michael]

Originally Posted by D&C ERV2

... 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 like how you've done this. Current generation cells and BMS with the original well designed mechanicals.

[chowdog]

Are you still happy with your Sun Fun Kits modifications?

[D&C ERV2]

Still very happy with the system. The only thing I have still to attempt is to improve the Bluetooth connection. By using the metal case and the batteries being outside I have to go to the back of the van outside to get a good connection. I am going to try removing the lids a to see if that helps and if it does, I am going to make plexiglass lids to replace the metal ones. I am in no hurry to try this because it is for convenience only. SFK has an option for an internal monitor, but My van never had one and I didn't think the extra money and time would be worth it to add one

[booster]

Originally Posted by D&C ERV2

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 am a bit late to this, as I normally don't get much into the old Roadtrek systems that were never very good and and also pretty much obsolete, IMO.

I am interested in home DIY stuff like this for lithium as there are so many different ways to address, or not address lithium's weaknesses vs strengths.

On you 3 pics, it appears the first is the KY2 and the next two are your replacement systems.

It appears the BMS is under the cells? Never seen that before.

I also don't understand the the positive cable location in the next two pics as it appears to go to a different place on the two pics.

Plus a couple of questions.

Do you have an anti swell band or such on the cells?

Do you have a temp sensor in the batteries that will display and show you what the running temp is going down the road? I ask because we have had an AGM system behind the rear axle where the generator was, in our 07 Chevy Roadtrek. 440ah of AGM with 4 6 volt batteries in line across side to side. Running down the highway in hot weather (100+ degrees) they would get to 120* even though they were completely baffled from the front and sides to keep hot air off them and not charging going on. We would turn off the alternator charging in such temps.

Lithium is even more susceptible to high temp damage than AGM by most information available, so when we did our lithium upgrade I put them inside the van begrudgedly. Underbody would have been easy as everything was already there, but the heat would likely cook the batteries.

ARV has used sealed and super insulated boxes to address the issue. Avanti built a cool air ventilation system for his new van setup with the batteries underbody so he can probably update us on that if he chooses. Most systems are now put inside the vans, it appears.

High temps may have been one of the contributing factors in the original Roadtrek problems with the lithium systems, but nobody has ever investigated that part of it that I have seen.

[D&C ERV2]

In the first pic it is a KS2 with the lid removed. The second pic is the rebuilt battery using the calb cells that came with the KS2. The BMS in this one is mounted on the vertical aluminum plate in front of the cells. The third pic is the 280 AH battery built with cells from SFK and the BMS is on top under the green riser plate. The positive cable looks different because of the different builds. I didn't use anything for swelling except for packing them in the box very tight. The SFK kit comes with two temp sensors. One for the case and one for the cells and I was worried about temp at first but after checking during stops I have never seen above 95 degrees even in the battery that is 6" away from the exhaust. I don't see how these vans can have the batteries inside without eating up a lot of storage or putting them under bench seats that I don't have and don't prefer in the design. My opinion of the KS2 Problem is that the original batteries had a charge and discharge connection that allowed the current to continue charging even when the charge relay was not active. They were also wired wrong. The Balmar voltage regulator was set to high and not set to shut down soon enough. I know this because I changed my settings in the Balmar to a lot more conservative charge Amp and duration using a Document I received from KS2. The last thing that I would say is that the under-hood AGM is not there just to provide voltage for the relays inside the KS2 to work but more important to absorb the charge from the UHG during all the stop and start driving. From all my research the AGM will take a lot more punishment than the Lithium. I had to replace my AGM just before I rebuilt the Lithium's, and I used a Renogy 100AH because I found it on Amazon cheap. I no longer need the AGM to get the relays to work (If we truly ever needed it for that) however because of the beating it will take and the lower cost I would recommend getting the biggest AGM battery with the most AH possible. I know there will be those that are concerned about the need for different charge parameters, but my system is working great, and I haven't spent a lot of money on components to accomplish different charge parameters. Don't forget to check the Inverter settings on these vans while you're at it and do your best to match the Balmar. I am researching the conservative settings because I am worried that the lithium's are not getting to 100% state of charge. I am getting to 98%

[D&C ERV2]

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.