Lthium charged with mppt controler

[Rmcgrath53]

I emailed morning star about the topic and this is there response.







Morningstar Corp. Tech Support via 2v4xqg71s4mcvgo6.4x8azg5z2ljisu01.qn4ugr2.3-oneaeai.na13.bnc.salesforce.com


1:45 PM (2 hours ago)








to me

??what is meant by battery management system . ??and does it mean the float and equalizing function not needed?

Thanks
Ron








Two main types of Lithium batteries:

Lithium ion: With some system modifications, lithium-ion batteries can be used with Morningstar MPPT controllers (TriStar and SunSaver). The battery bank must have a built-in or connected battery management system to monitor cell voltages. Further, the battery management system must NOT have an automatic full charge disconnect feature that breaks the controller connection to the battery. The controller will not operate without a power source. Finally, the controller needs to be programmed / set to disable the float and equalization stages so that current to maintain absorption voltage will be available at all times.

LiFePo4: Even though Morningstar controllers are designed for use with lead-acid batteries, lithium iron-phosphate batteries can be used successfully with programmable units. If using this battery technology, please check with the manufacturer for recommended set-points and current restrictions.

Any diversion function would require a separate Diversion Controller, such as the TS-PWM controller.

what is meant by battery managemwhat is the ent system ...and does it mean the float stage and the equalize stage are not used

[mena661]

Gde, seems we are mostly in agreement. There is no BS here. Not sure why you don't understand that a different chemistry can have different characteristics. LiFePo4 is an order of magnitude safer than LiCo. That's just a fact. If you choose not to accept it, that doesn't make the battery any less safe.

The reason EV folks did not experience any "fires" was for the fact that EACH INDIVIDUAL Lithium cell HAS a BMS CHIP BUILT INTO IT.

Incorrect! Didn't see this before. The EV guys build their own battery packs (hence DIY EV). They take the raw cells, strap them together, and connect a BMS of their choice. Some don't even use BMS's. Those tests were done without BMS's connected. They didn't catch fire (so scary that fire word) because they're simply not as energy dense as LiCo.

[Gdetrailer]

mena661 wrote:

Gdetrailer wrote:

Run without this protection and the result is nothing short of a spectacular 2300F degree fire..

Unless you really have top notch understanding of all the charge/discharge parameters of Lithium batteries it is best to leave them in profession hands..

Perhaps another 10 or 15 yrs they will find better ways to deal with the potential hazards but not as of yet..

your batteries BMS system would have to fail at the same time to allow this to happen.

That IS why the battery cells MUST HAVE A BATTERY MANAGEMENT SYSTEM.

The reason EV folks did not experience any "fires" was for the fact that EACH INDIVIDUAL Lithium cell HAS a BMS CHIP BUILT INTO IT. The built in BMS chip monitors the cells temp, voltage and how much current is being drawn or put back in.. That chip will disconnect the cell if it detects anything out of the design parameters.

The only way around getting cells without a BMS chip is if you yourself find a manufacturer which you could sweet talk them into selling you RAW CELLS.. and that is not going to happen.

BMS chips are not fool proof and they DO FAIL, typically they fail in the disconnect mode but they CAN fail and not disconnect..

A company I worked for had several cases in which a product we sold HAD several documented cases of the LI battery bursting after being freshly charged in the proper charger causing burns to hands and even one that caught fire in a pocket.. We didn't manufacture the product, we bought it prebuilt from another well known company and added our software package to it.. then resold it with our software package.. My company discontinued that product shortly after that..

Back a few years ago there was a spectacular recall for MANY laptop brands which used a certain manufacturer for their LI batteries.. The reason.. A manufacturing defect which allowed impurities to create a electrically conductive "whisker" which would short out the affected cell causing the batteries to overheat or even start a fire..

Don't hand me any BS that a different LI based battery is "better" for safety than others.. They can and do fail and due to the shear energy storage in that little package even an accidental short by a person can trigger an event which just may not be a good thing..

While the iron phosphate are more stable it doesn't mean they are totally safe either.

[jrnymn7]

The only issue I see is cell matching... and that starts with the manufacturer and distributor. Provided the cells are well matched, the BMS will have to do little more than monitor. I have seen it described as the last line of defense, not the first.

[Ductape]

Mena is right, I don't recall seeing a lot of reports of flaming consumer electronics and lithium is everywhere. BMS are commonplace. Just needs to scale up to RV sized systems as the price points change. It won't take too long as soon as the economic math makes it desirable.

[mena661]

Oh yeah, another thing. Disable the temperature compensation on the solar controller.

[time2roll]

You need to contact the battery manufacturer to get charging specs and details of the battery management system. Morningstar makes the solar controller not the battery.

[mena661]

Gdetrailer wrote:

Run without this protection and the result is nothing short of a spectacular 2300F degree fire..

Unless you really have top notch understanding of all the charge/discharge parameters of Lithium batteries it is best to leave them in profession hands..

Perhaps another 10 or 15 yrs they will find better ways to deal with the potential hazards but not as of yet..

Guys get off the everything catches fire trip already! LiFePo4 will NOT catch fire the moment you overcharge! All Lithium Ion are NOT the same for the 10000000000000000000 time! Do some friggin research! Some folks on the DIY EV forum have deliberately overcharged their LI batts and absolutely ZERO caught fire (there was physical damage to the cases...bulging). You would literally have to GROSSLY overcharge them for hours and hours and hours, maybe even days, well past physical damage to the batts themselves AND your batteries BMS system would have to fail at the same time to allow this to happen. Here's a fun fact, you and I CANNOT buy the LI batteries that are used in cars, cell phones, laptops, or the Boeing 787. The LI batts we'd used are LiFePo4 which have totally different characteristics than those used in the vehicles and electronics I mentioned.

[Gdetrailer]

Rmcgrath53 wrote:
I emailed morning star about the topic and this is there response.







Morningstar Corp. Tech Support via 2v4xqg71s4mcvgo6.4x8azg5z2ljisu01.qn4ugr2.3-oneaeai.na13.bnc.salesforce.com


1:45 PM (2 hours ago)








to me

??what is meant by battery management system . ??and does it mean the float and equalizing function not needed?

Thanks
Ron








Two main types of Lithium batteries:

Lithium ion: With some system modifications, lithium-ion batteries can be used with Morningstar MPPT controllers (TriStar and SunSaver). The battery bank must have a built-in or connected battery management system to monitor cell voltages. Further, the battery management system must NOT have an automatic full charge disconnect feature that breaks the controller connection to the battery. The controller will not operate without a power source. Finally, the controller needs to be programmed / set to disable the float and equalization stages so that current to maintain absorption voltage will be available at all times.

LiFePo4: Even though Morningstar controllers are designed for use with lead-acid batteries, lithium iron-phosphate batteries can be used successfully with programmable units. If using this battery technology, please check with the manufacturer for recommended set-points and current restrictions.

Any diversion function would require a separate Diversion Controller, such as the TS-PWM controller.

what is meant by battery managemwhat is the ent system ...and does it mean the float stage and the equalize stage are not used

Lithium batteries HATE to be over charged, HATE being over discharged, HATE having too much current drawn, HATE being force fed too much charge current.

Hence as to why they REQUIRE a BATTERY MANAGEMENT SYSTEM which monitors each cell voltage, current and such..

The management system will shut off current in the even of over discharge, over charge, too high of charge voltage and so on..

Run without this protection and the result is nothing short of a spectacular 2300F degree fire..

Unless you really have top notch understanding of all the charge/discharge parameters of Lithium batteries it is best to leave them in profession hands..

Perhaps another 10 or 15 yrs they will find better ways to deal with the potential hazards but not as of yet..

[KJINTF]

Deleted - Double post from this darn site happens all the time

[KJINTF]

Those darn "DIP SWITCHES"

Sure hate to see folks purchase a nice new high end controller and simply set a few switches and call is good

[mena661]

Lithium Ion batteries require a Battery Management System (BMS). LI batteries can be permanently damaged from overcharging or over-discharging. The BMS prevents overcharging, over-discharging and performs cell balancing. BMS's can do other stuff but that's the minimum.

MEXICOWANDERER wrote:
I can see it all unfolding as I write this

"Dang! And here I thought the dip switches were set to 0100110"

MEX the Tesla caught fire because the battery pack was penetrated by road debris. That damage you see in the pic was caused by the debris. Also, Tesla batteries are LiCo not LiFePo4. TOTALLY different chemistries although in the same "family".

[MEXICOWANDERER]

I can see it all unfolding as I write this

"Dang! And here I thought the dip switches were set to 0100110"