Hoping someone can help me! On my 5th wheel RV I installed a MultiPlus ll 2x120, 1 Enduro 300 ah Lithium Battery, and 800 watt solar a couple years ago. The solar works great and the system has served me well but I do need to charge my battery occasionally with my generator. I have tried every setting I can think of but I cant keep my Generator from surging up and down. The best I can do is about 1000 watts then it will fall off to almost nothing then cycle back and forth. I have a Westinghouse 4400 watt Inverter generator. I was hoping the larger gen would allow me to charge fast to not be a nuisance to other campers but bouncing from 1000 to 0 watts will take forever and the sound is very annoying! I have discharged my battery to about 25% to do the testing and adjustments. It seems the voltage is spiking above the 14.4 absorption voltage, sometimes up to 16 volts, shutting the charging down to a low rate, then back up again. I can get it to smooth out if I turn the charge current down to around 30 amps and getting about 250 watts charging. Im starting to think my Battery may just not take enough charge at a fast rate but I seem to remember the max charge rate on the Battery was like 120 amps! Unfortunately, Enduro has gone out of business, so I cant get any help from them but the Battery holds a lot of charge and will last us all day and still be at about 70% doing normal things while dry camping. I have tried Turning on the Dynamic current limiter but changes nothing. I’ve tried hundreds of combinations of different AC input current limits and charge currents and nothing works. I did notice when I plugged into my 50 amp shore power the charging watts was bouncing up and down just like on the generator. I will include my current VE Config settings and appreciate any help anyone can give me. Thank You in advance!
Does the LiFepo battery have its own BMS where you can check the cell voltages?
Check all cable connections from the Multi to the battery. Maybe you have a Single Cell with a Overvoltage and the BMS shut down the Charging
If you have 2 units in split phase, the charge current should be double what you have in Veconfig. The 60A you have in there will be 120A. You should try and lower the voltage. If you have a BMS disconnect at 14.4V, try 13.8V and then raise it to 13.9V, 14V and see if it keeps disconnecting. If you can do absorption at 13.8V, the battery will 99% charged.
It is a “Splitphase Multi”- “MultiPlus ll 2x120”
The Charger only work on the L1 Leg of the Splitphase
Hi, My thoughts on this would be:
Your 4400w generator could produce 37Aac @ 120v.
When this is converted to DC (120v(ac)/14.4(dc) = 8.3 * 37Aac) for battery charging this could become a potential 307Adc. Solely limited by your MP DC charging output.
You mentioned you have a single Enduro 300Ah Lithium battery.
Almost without exception the maximum charge rate for lithium cells e.g EVE is 1C (300A).
I would investigate the battery BMS settings and it’s Alarm logs.
I suspect you are experiencing the BMS shutting down charging based on Over Current Charging Protection, it’s also possible there may be an issue with Cell Over Voltage Protection too as pointed out by @Netrange .
My first ‘test’ would be to limit the input current to 13Aac (reducing your battery input Current to about 108Adc). This would be a more comfortable 0.33C charge for your battery BMS, and would also help increase you battery cell cycle life too.
Most lithium cell data sheets spec 0.25 - 0.5C for the nominal charge rate (for your battery this would equate to 75-150Adc ()).
You mention that when the input current is set at 30A (30Aac * 8.33 (120/14.4) = 249Adc) things seem to resolve the issue, and I suspect that is somewhere close to the Charging Over-Current protection threshold on your BMS (if this was set at 85% of 1C, that would be 255A)
Do you have the original battery and BMS manual??
If this was your battery supplier, you can see the list of BMS protections, but there are no thresholds specified: Lithium Battery FAQs - Life and More | Enduro Power
The BMS app on the the Play store looks like a fairly typical end user, limited interaction BMS app. That is to say they design for safety and life, and don’t enable end users to make changes to BMS settings, meaning you may well just have to live with what you have. This is one of the reasons I build my own LiFePO4 12V batteries utilising the JKBMS 200A.
I’d also say this:
Fast charging degrades battery cell cycle life more than any other action.
LiFePO4 likes to cycle between 60-90% SoC for maximum cell life.
Maybe you could post a screenshot of your battery BMS settings and Alarm logs, if they might be of any use?
I have some node red code that dynamically reduces the charge current as the voltage rises i posted an example for another poster. I do this for one of my systems, so the solar finishes off the charging. You might be able to see how I do it and use some of the code. Just change the values to a 12v for example, start reducing at 13.6V and have the min current at 14V. This works really well because as you reduce the current, the voltage also drops.
It has a BMS but I have no idea how to communicate with it. Pretty sure there’s no Bluetooth connection to it. Harrison Smiddy, Enduro Owner, was very helpfull when I bought the battery but his number has been disconnected. Enduro says max voltage is 14.6 so I’m sure it’s shutting me down and causing the oscillation. All connections are secure. Thanks for your reply!
I did try lowering the voltage to 14 but will try it lower. Thanks
Do not know how to do that.
[quote=“NeptuneUK, post:5, topic:34175”]
I suspect you are experiencing the BMS shutting down charging based on Over Current Charging Protection, it’s also possible there may be an issue with Cell Over Voltage Protection too as pointed out by @Netrange .
[/quote] I am sure of this!
Sadly, I do not. This is on their website
I really appreciate you guys spending time to help me. I will do some more experimenting today and let you know how it turns out. I do have a 2000 watt Champion generator and may just use it and be satisfied with a slow charge rate.
Have you installed their BMS app? They have an Android and Apple version on the respective app stores and it’s free to use.
If you installed that app, enable BT on your phone, you should see the battery and it’s info.
I wouldn’t drop the voltage any lower than the 14v you already tried. Their HV cutoff is 14.6v which is 3.65v per cell, I set my charging voltage to a slightly more conservative 14.4v (3.6v per cell). It is possible a single cell is triggering the HVCO, but that would indicate a different, more physical issue. I’m sure this isn’t the case. I’m more confident now, that you have a High Continuous Over Current issue.
I’d set your MPII for 14.4v and limit the incoming shore (genny) current to 18A (0.5C for charging).
If possible, you could always increase your solar array capacity to alleviate charging requirements from other sources?
I downloaded and installed the Enduro App but it won’t find the battery.
[quote=“NeptuneUK, post:12, topic:34175”]
I’d set your MPII for 14.4v and limit the incoming shore (genny) current to 18A (0.5C for charging). I did this and everthing settled down with a charging rate of 200± watts or 18 amps. I started playing with the parameters again and it started surging. Went back to the above settings and now it will not settle down. Very Frustrating! It would be very interesting to acquire a different charger and try charging the battery. My Renology Solar Controller will charge at up to 600 watts without surging… If I can get the 200 watts to be acceptable, it will still take me 8hrs running my generator to get half of my battery capacity…Thanks for your help, if nothing else, I have learned a lot from all this.
Shame about the App, as that info would have been useful. I read that maybe only the Enduro Pro Connect had BT.
Did you mean a charging rate of 200w or 2000w @ 18A?
As for the surging, are you convinced and have you tested, that the battery is not at capacity?
Also does your genny have an ‘eco’ mode / smart throttle?
Charge your battery and when the charging DC amps drop off or the surging starts, disconnect the battery from loads/charging (genny and solar), and after 10 mins take a voltage reading at the battery terminals.
Anything close to 13.65v - 13.8v would indicate your battery is fully charged (LiFePO4 is really charged at 99% and cells would be at 3.45v at this point, after a short rest they will settle at a nominal 3.35v per cell in most cases and sit at that or there about even under load until nearing the end of the discharge curve), and that might account for the surging as the BMS keeps switching the charging MOSFets off (as the cells or even a single cell reaches the Cell Protection voltage (3.65v)) and then back on when it’s balanced out the 4 cells.
I’d consider creating a hybrid system (if you are comfortable with implementing that) as you only have a single LiFePO4.
Aftery battery setting overnight was at 13.1 v today at rest. Tried charging with gen with DC current limit set at 18 amps (about 216 watts). Gen would not settle down! bouncing up and down. Went on shore power and it did the same thing! Bouncing between 200 and 0 watts. Can’t tell if my voltage is hitting the 14.4 absortion rate or not as I get a reading intermittently from my Victron BMV-712 battery monitor. I think I may have seen a 14 something flash across a time or two… I then discharged the battery down to 12.8v and tried charging again. The 2000 wat Champion invertor gen was bouncing up and down trying to charge at 18 amps. On shore power, charging went nice and steady even up to 500 watts… Im going to pull it out tomorrow in full sunlight and see how my 8-100 watt solar panels do…Im starting to suspect my battery being bad.
[quote=“NeptuneUK, post:14, topic:34175”]
I’d consider creating a hybrid system (if you are comfortable with implementing that) as you only have a single LiFePO4
[/quote] What is that?
Google “Hybrid Lithium system”
Given the voltage reading of 13.1 after settling over night (I’m assuming you had 0A current draw?), I’m starting to come to the same conclusion if that is the case.
I’d also try charging via a direct LiFePO charger (stand alone; completely remove the battery so it’s just: charging source->charger->battery) and see what happens. This will serve to rule out any other potential issues such as charger, cabling, connections, fuse etc.
If you decide to replace it you could always dismantle it - carefully - and replace the BMS? I suspect it’s the BMS that is the issue.
I also did a bit of looking around. The following is the conclusion I came to. Enduro power batteries was essentially a one man band. He had over promoted himself, and wasn’t able to grow his business AND handle sales AND support all at the same time. The product looks like a straight rebadged standard Chinese lithium one. Alot of the YT content seems to be produced by channels that got the batts gifted. I prefer ones that buy their own items then review
If you look for a replacement really do consider Victron lithium. Why? It’s a robust product, back by an international company with a huge distributor and support network. Sure their batteries are in a higher price band, but you do get all the additional benefits and a solid product.
The battery had 13.1 in it the night before…If I replace the battery, I’m definatley going 24v. My solar wiring is maxed at 800 watts but I’ve got room on the roof for several more panels.
So, with my Multiplus ll turned off, I pulled my camper out in the full sunshine and it charged a good 500+ watts steadily 7 hours. It occasionally dipped down to 350watts. One thing I noticed is the voltage on the battery is stayed very steady close to 14.4 v when charging with the solar…
The multiplus ll had voltage bouncing all over the place causing the Generator and the shore power to surge. I’ve had this system for several years and never really paid attention to the Multiplus ll charging rates. I’ve just recently tried charging with a generator. If I cant get this ironed out, It may be best to bypass the Multiplus ll and go with a dedicated charger. Shame, after spending a grand on a fancy Inverter/ Charger!