Faulty Lithium BMS - Replacement Advice Wanted

[Jim Gell]

A few weeks ago someone was asking about Balqon Lithium Battery Packs in a post. I posted a brief reply, but didn't want to spend a lot of time posting on something I was still trying to figure out. I said then, and I will say again, from my experience I cannot recommend anyone buy from Balqon. I have found several posts on various forums from customers like myself who get no response from them when trying to contact them. One poster went to the business address recently and found they had moved. They are not posting their new address and phone is disconnected. Messages to CEO's ? cell phone go unreturned.

 

I am posting today to get advice on my system repair. I was previously thinking I just needed to tweak my charging settings from solar controller and/or inverter to get the battery pack's BMS to stop tripping. Now, with both positive and negative connections to the lithium bank physically disconnected, the BMS trips off when I turn the BMS on. Cell voltages are in the "flat" normal range at 3.32V. So it appears there is a malfunctioning component in the BMS or one of the 4 solid state cell monitors. We are now using a 12V lead acid battery.

 

Balqon should have responded to my requests to replace the BMS system, but have not. I can't say I know they are bankrupt or totally out of business for sure, but I think it is wishful thinking they are going to offer assistance in a timely manner. Therefore, I have started looking for a more pragmatic solution to get us back in business while I try to get a financial remedy through our credit card company.

The House Bank BMS, cell monitors, and display products from Clean Power Auto LLC look like something I could install myself to solve my issues, The BMS would have advantage over what I have now in that I could rewire my system so that the battery would still be chargeable with low current shutdown and able to draw power off in an overcharged condition. That may not be necessary if everything works right however.

Would the more technically savvy folks on here take a look at these products?

House BMS (product link) House system pdf (sytem info)

Cell Monitors

Display Not sure if this is going to be redundant with the Magnum Inverter and Midnight Solar equipment I already have. I am inclined to get it with the Bluetooth interface unless someone explains why I don't need/want it.

I was thinking of ordering all the above components from them to totally replace my BMS to be sure everything was compatible. I could buy one cell monitor for under $30 with shipping and try swapping it out with each of the 4 existing monitors, one at a time. Maybe there is a better way to test the cell monitors, but it is over my head. Any thoughts on that aspect?

I did see on an EV forum that Clean Power was in business at least since 2009 and are located in Tampa. Didn't find much in reviews, only a couple positive comments on the cruiser forum.

Anybody have any opinions before I place an order?

Jim

 

[Yarome]

I certainly wouldn't call myself "savy" with LFP systems, but in reviewing the specs from the links you posted, I really don't see any red flags and I don't find anything "popping" on their company itself. Their prices are certainly reasonable and might consider purchasing from them myself. I have no practical experience with their gear, but it specs out.

 

The battery display/monitor... if you have the battery sensor module on your Mag then it would be redundant and it's not all that feature rich for the price. I also don't see anything in the specs that would indicate there's anything specifically engineered for lithium applications... just a "ho-hum" run of the mill monitor, IMO.

 

Bluetooth would have to be a personal choice. It's "nifty", but bluetooth really isn't all that energy friendly (being an RF transmitter). I would do a pass, but I'm also a little anal about efficiency and have never been in a situation with a power system that required that level of immediate monitoring. Or at least.. not to any ill affect on a power system.

 

Sure sorry to hear about all the Balqon fiasco. That's gotta sting a little. I do know that they have been struggling greatly over the past 3 or 4 years with some massive loss reports (over 60% in one quarter alone not too very long ago). Bankruptcy has "been in the wind" for much of that time. I don't have any up to date info, but I wouldn't be at all surprised at a restructure or out and out bankruptcy. The CEO has been quoted more than once, "If we cannot restructure our debt and obtain sufficient liquidity in the very near term, we may need to seek to protection under the U.S. Bankruptcy Code.“

[Ronbo]

I have been looking at the clean power system. Hopefully I can begin working on a system next year and if so I plan on using their system. I don't think you need the display. There is an android app for the classic solar charger that tells you state of charge.

[Daveh]

Jim. It is a lot to work through but the Cruiser Forum on LiFepo4 does have discussions about the Clean Power system. http://www.cruisersforum.com/forums/f14/lifepo4-batteries-discussion-thread-for-those-using-them-as-house-banks-65069.html.

 

It is a popular option. I have it, but have not yet installed it.... I do not think it willbe a difficult install (but I have said that about other things and been wrong).

 

I will write some more tomorrow. We are at Disney and I am exhausted (aging sucks).

[Jim & Wilma]

Jim,

 

I’ve read a lot of discussion about the value of an active BMS that aids in balancing the cells. Some argue it’s introducing more failure potential and solving a non-problem. In our typical RV applications with fractional C loads, seems many knowledgeable folks recommend just bottom balancing on the initial install. You do need to have a low voltage cutoff device. I assume you have the contactor as part of the Balqon setup and may just need low voltage detector set at 12.X volts depending upon your Lithium chemistry and what depth of discharge you’re willing to go to; 80% is often referenced as a cutoff. If you have the Magnum BMK or Trimetric, not sure what value another meter might have.

 

Good luck . . . Jim

[Daveh]

The value of the other meter is that you get a measurement on each cell rather than the combined cells in serial as with the BMK and Trimetric. So, other than just redundancy to back up the other meters you are also getting the benefit of making sure that one cell is out of balance and being damaged.

 

The designation BMS is confusing becuase we could be refeering to either a passive cell monitoring system or an active cell managment-balancing system. I agree from what I have read that the active balancing aspect of a BMS system may not be necessary with out low C usage. The Clean Power system does have some active managing circuits but it sounds like some folks set their high level cutoff, low enough, that those circuits shouldnot kick in if everything is relatively in balance. The knock against the active management system is that it just introduces one more element where you could have a failure when the need has not been demonstrated (fails the risk-reward analysis).

 

The Clean Power system will give you alarms on low level and high level at the cell level. Jim is right that you need to purchase a contactor (another 60-100 bucks) to add the capability of system shutdown rather than just alarm. I bought one off of ebay (not yet installed).

[Jim Gell]

Thanks for everyones input. The Balqon battery pack came with a contactor. An issue with the Balqon set up that I would like to improve upon is that the contactor disconnects the battery to prevent both over discharge or over charge. When one of those conditions occurs, it would be nice if the battery is protected in a way that let's me discharge an overcharged battery, or charge an over discharged battery.

 

I am thinking the contactor must be set up the way it is on the Balqon to simply disconnect the battery. However, this Clean Power BMS looks like it might be able to be wired to my solar controller and inverter to stop them from charging the battery when voltage gets up to a point I set that would be less than will trip the contactor off. Any comments on that line of thought?

 

That still leaves me with a situation where if I draw down the battery too low for some reason, such as boondocking without adequate sun or running my manually started generator, the BMS will disconnect the battery, and then I can't charge the battery. I am not sure what the best solution to that would be. Again, any thoughts?

 

Keep the comments coming. Thanks.

 

Jim