Problems after converting to lithium house batteries in a Travel Supreme MH

[jaysigel]

I do all of my own routine maintenance on my motorhome and after almost 18 years, I can repair most things, but I have my limits. I certainly don't want to have the vehicle disabled while it's in my garage!


I don't know if anyone has tried this. We have a 2006 Travel Supreme DP, 38', acquiring it new in 2005. I bought 2 Battleborns at the Quartzsite RV show in 2020 and then the pandemic hit. Last year, having read all of the postings about isolating the engine alternator from the lithiums, I installed the Victron DC-DC converter and isolated the house batteries from the engine batteries. During this process, I discovered that there was an ignition-activated relay (located under the inverter-charger) that interconnected the coach and chassis batteries that had fused in the closed position and I replaced it. Its function appeared to be connecting both battery systems when the engine is running so that the alternator would charge both. Since it was triggered by the ignition switch, I ungrounded it. It's now a new relay that never does anything. The latching solenoid to the house main power toggle switch had also fused in the closed position and I replaced that.


The lithium batteries will run down after a day or two. Below 11.5 volts, the inverter-charger will not work. They don't seem to get any lower. Charged they read around 14 volts. The shop has been repeatedly warned to either plug in the vehicle or run the generator when working on the electrical system.



A number of possible coincidences occurred:


1) Last year, a new Magnum Energy MS2012 (full sine wave, 2000 watts) inverter-charger stopped working properly. It would power-off, pulling in 2600 watts, after 1 minute while powering a 1200 watt microwave oven (the Victron Connect app let me see this on my smartphone). I won't get into the warranty issues with Magnum (Sensata) but they have yet to replace it. I had an older but functioning ME2012 (square wave) and installed that in its place without any obvious problems, however, it is not designed to work with lithiums. Programming help was received from Dragon Fly Energy, who sell the Battleborns and the entire Victron line.



2) An AE power awning stopped working. It would extend a little and stop. Waiting 10 seconds, it would then move again. After a while, it wouldn't do anything. A new motor was installed and the shop said that the new one was defective and had markings on it suggesting that it had previously been returned. The shop said that the defective new motor had damaged the controller and they replaced the awning controller as well as another new awning motor. Of course, I was skeptical! It has been working but not consistently. When we arrived to pick up the RV from the shop last week, the house batteries had declined to 11.5V and the battery management system (BMS) had shut them down. While running the generator and doing bulk charging for 1/2 hour, I operated the EQ System hydraulic jacks and the awning didn't work. On repeat testing with the service advisor present, there were no problems with the awning. See 3 below.



3) The EQ System would not do an auto-level or retract-all without an error beeping indicating low voltage. I could do a retract-all when the engine was running, but it couldn't do an auto-level (locked out during ignition on for obvious reasons). A clue: If I applied jumper cables between the chassis batteries and house batteries, the jacks then worked fine. Were the engine batteries bad since they had been connected to the house batteries for an unknown length of time? I replaced the engine batteries. That made no difference. I brought the RV to the shop to repair this, supplying all of the information I had on the changes made to accommodate the lithium batteries, the new engine batteries, the relay, etc. Other issues were problems with the air brake pressures. They replaced the compressor (inside the engine), and found multiple line leaks, which were all repaired. They replaced 2 front air bags to improve handling. The shop, which we trust, is 75 miles away from our home and we arrived to test drive it and take it back home after everything was said to be repaired a week ago. I noticed the low lithium voltage and the fault message on the Magnum monitor when I stepped inside to start the generator. The charger took over, doing a bulk charge and the voltage came up. We road-tested it and it handled well, driving it about 2 miles on I-45. We took it to buy some diesel and then back around the corner to the shop. There we tested the hydraulic jacks in their parking lot. They worked fine but we smelled burning electrical wiring. At the same time we attempted to extend the awning and it didn't work until the jacks had finished extending. We retracted the jacks and called in the service advisor and neither of us smelled anything unusual. The jacks were then extended and the awning worked at the same time. But, the jacks then refused to retract and we were stuck in their parking lot! The mechanic was called over. He checked the fuse on the hydraulic jack pump motor (it was intact), pulled off the controller from the dash and there was an obvious burned spot on its circuit board right around the plug for its power. A different mechanic had worked on it and he told the service advisor that the jacks were now connected to the house batteries. He also noticed an intermittent "puff of smoke" when connecting the controller!!! This all occurred last week after having the RV in their shop for 6 weeks. How they got the jacks back up in order to be able to move the RV last week, I don't know.


Lots of things happen to an older RV. We can't afford a similar quality new one at this time. This is a full service RV shop. They do engines (not transmissions), routine maintenance, body work, towing and so forth. We trust them while realizing that no one's perfect and things happen. This could all be coincidental. But it is temporally related to isolating the engine and house battery systems. I would like to benefit from anyone's similar experiences with RV electrical systems and lithium batteries in particular. Thank you.

[Harry B]

Check to see if your DC to DC charger is turned of when the coach is not running.

It needs to be switched on when the alternator provides voltage or engine is running and be switched off when no alternator power is provided or the engine is off.

If the DC to DC charger stays on without the engine running, it will drain your batteries in a hurry. Ask me how I know😊

[dssl]

Wow way too long for me, I read for a while, then gave up.

You mentioned you have a DC to DC charger, and that you replaced the merge relay. With a DC to DC charger the merge relay should be de activated, it's not clear if it's deactivated or not.

Your Victron ME2012 is a modified sine wave inverter, not a square wave inverter which is different. A square wave inverter has only 2 voltage levels, while a modified sine wave has more then 2 voltages to closer approximate a sine wave. Pure sine wave is way better then modified sine wave, which is way better then a square wave.

It sounds like you have had allot of issues which is obviously frustrating, but it's unclear how those problems relate to your LIFEPO4 upgrade. Other then checking for loose connections, and tracking your voltage and maybe doing a capacity test, not much I can think of.

Most people with LIFEPO4 actually have fewer issues with their 12v system, since lithium provides a higher more stable voltage.

[jaysigel]

I'm sorry for the long post, but a lot happened and it might all have been coincidental, but maybe not.


The merge relay is deactivated, as stated in the post. The old one had fused in the closed position, but I replaced it. I removed its grounding wire, so it does nothing.


The Victron DC-DC converter works as intended. Victron Connect is a free Bluetooth app and from it, one can monitor the Battleborns' shunt readout and the DC-DC converter performance. It gets pretty hot, but that appears normal. The device is pretty smart. It "knows" when the engine is running vs. the ignition just being on. The only connection between the alternator and the lithium batteries is through the converter.


How things are supposed to be wired is the question. The power awning doesn't appear to have an ignition lockout. It is connected to the lithium batteries. The EQ System hydraulic jacks has an ignition lockout. That means it must monitor the ignition switch, which is obviously connected to the chassis batteries. Yet, the shop connected it to the lithium batteries for operation.


I drove up to the shop today. They're pretty far from us, a good 75 miles each way. I was going to drop off a JC-Refrigeration cooling unit for our Norcold 1200. But when I found out that they had done nothing to locate a replacement for the burnt up jack controller, I told them never mind with the refrigeration update. Either I'll do that myself or take it to Indiana. The vehicle has been in the shop since March 23rd and I'm getting discouraged.

[dssl]

Originally Posted by jaysigel

I'm sorry for the long post, but a lot happened and it might all have been coincidental, but maybe not.


The merge relay is deactivated, as stated in the post. The old one had fused in the closed position, but I replaced it. I removed its grounding wire, so it does nothing.


The Victron DC-DC converter works as intended. Victron Connect is a free Bluetooth app and from it, one can monitor the Battleborns' shunt readout and the DC-DC converter performance. It gets pretty hot, but that appears normal. The device is pretty smart. It "knows" when the engine is running vs. the ignition just being on. The only connection between the alternator and the lithium batteries is through the converter.


How things are supposed to be wired is the question. The power awning doesn't appear to have an ignition lockout. It is connected to the lithium batteries. The EQ System hydraulic jacks has an ignition lockout. That means it must monitor the ignition switch, which is obviously connected to the chassis batteries. Yet, the shop connected it to the lithium batteries for operation.


I drove up to the shop today. They're pretty far from us, a good 75 miles each way. I was going to drop off a JC-Refrigeration cooling unit for our Norcold 1200. But when I found out that they had done nothing to locate a replacement for the burnt up jack controller, I told them never mind with the refrigeration update. Either I'll do that myself or take it to Indiana. The vehicle has been in the shop since March 23rd and I'm getting discouraged.

As far as the Orion DC to DC charger, mine needed a cooling fan to force air through it, otherwise it got very hot and didn't out out many amps. If yours seems to be running hot it's something to consider.

This is the one I got,put it 1/2 inch or so bellow the Orion, and is controlled with an ignition signal, as is my Orion which is desirable if you trickle charge.

https://www.amazon.com/gp/aw/d/B07RM...b_b_asin_title

As far as the awning having an ignition lockout. Are you sure it changed? Looking at my Tiffin motorhome the awning is powered off a relay based on the parking brake, so no ignition lock out. It would be really odd for them to change how the awning is powered when they do a LIFEPO4 upgrade, since it would create more work and have no useful purpose.

[Captain8]

It sounds like the batteries aren't able to pull as much power as you're requiring from them. Lead Acid can take a beating and you get a slow consistent voltage drop when under load, Lithium gets an immediate drop when the load is more than its rated, to the point the BMS will reset. This is much larger when you have 2 batteries together that aren't fully equalized and don't communicate with eachother when in parallel.

First off, disconnect 1 battery, run the devices and see if you're getting voltage drops under load. It should be twice as bad.

Second charge one battery with a dedicated Lithium trickle charger for days without any load. Make sure its fully charged and then all the cells will be equalized. Then do the same with the 2nd battery..... then connect them together, then apply the load. This will help keep the batteries equalized and cells inside the batteries equalized. Otherwise one cell will pull more load than the other causing voltage inbalances.

You stated Victron connect app so I'm assuming you have their smart shunt. Spend the $350 and buy a CerboGX then connect it. This will log your voltages. I have a very similar issue just larger when trying to run ACs off my 12V batteries. Attached is my log showing voltages dropping when load applied. I came to the conclusion my EG4 12V batteries aren't able to use 200a per battery like stated and actually only 50a so the BMS and other devices are tripping. I'm adding another 48V similar system so won't have this issue.

When voltages drop below rated use weird things happen and things break. Luckily my whole 12V system uses firefly which resets when voltage gets under a certain limit. Even my Victron CerboGX acts funky when getting 10-11V and I believe its rated for 7v

[dssl]

Originally Posted by Captain8

It sounds like the batteries aren't able to pull as much power as you're requiring from them. Lead Acid can take a beating and you get a slow consistent voltage drop when under load, Lithium gets an immediate drop when the load is more than its rated, to the point the BMS will reset. This is much larger when you have 2 batteries together that aren't fully equalized and don't communicate with eachother when in parallel.

First off, disconnect 1 battery, run the devices and see if you're getting voltage drops under load. It should be twice as bad.

Second charge one battery with a dedicated Lithium trickle charger for days without any load. Make sure its fully charged and then all the cells will be equalized. Then do the same with the 2nd battery..... then connect them together, then apply the load. This will help keep the batteries equalized and cells inside the batteries equalized. Otherwise one cell will pull more load than the other causing voltage inbalances.

You stated Victron connect app so I'm assuming you have their smart shunt. Spend the $350 and buy a CerboGX then connect it. This will log your voltages. I have a very similar issue just larger when trying to run ACs off my 12V batteries. Attached is my log showing voltages dropping when load applied. I came to the conclusion my EG4 12V batteries aren't able to use 200a per battery like stated and actually only 50a so the BMS and other devices are tripping. I'm adding another 48V similar system so won't have this issue.

When voltages drop below rated use weird things happen and things break. Luckily my whole 12V system uses firefly which resets when voltage gets under a certain limit. Even my Victron CerboGX acts funky when getting 10-11V and I believe its rated for 7v

Based on the specs from Battleborn each battery should be able to pull 80 amps without much voltagedrop, so two in parallel should be fine up to 160 amps. I'm guessing the OP isn't over that.

It wasn't clear to me his voltage was the problem, if it is then another option is he doesn't have his BMV set up properly, so he may not have as much charge as he thinks.