MPPT Regulator not to be used with Lithium batteries>

Monty10 · Member

MPPT Regulator not to be used with Lithium batteries>

Whenarewethere · Guru

A controller on the back of a blanket or panel is in the wrong place. Bypass it & install a controller next to the battery.

As a result you can avoid using a crappy controller.

iana · Guru

I have an MPPT controller that is suitable for lithium. You just have to change internal jumpers.

boab · Senior Member

the company that made my battery also made the controller the battery is lifepo4 the controller is mppt

Peter_n_Margaret · Guru

Buy from someone else.
Cheers,
Peter

Tony LEE · Guru

Certainly many controllers and chargers on the market that have no specific program to perfectly suit all aspects of lithium charging requirements
However given many drop-ins would be lying if they demanded special chargers, it is fairly safe to use them with a regular charging cycle. Not ideal of course

Jaahn · Guru

Monty10 wrote:
Hi,
I have just purchased a Kings 120w Solar Blanket after reviewing the specs on the web site. However I was surprised to see in the user manual, when opening the blanket after purchase, that the solar blanket and MPPT regulator are not to be used to charge Lithium ion batteries.
Stating that the MPPT controller is only suitable for Lead-Acid batteries. Is this common for MPPT controllers?
Luckily I purchased the blanket to charge up a Companion 40Ah Rover Lithium Power Station with a built in MPPT controller to allow direct charging from the blanket.
Cheers Monty10

Hi Monty smile

The simple answer is that particular MPPT charger they have selected to sell is not suitable, probably because it is cheap and does not have adjustable settings suitable for lithium. If they say it is not suitable why argue ? confuse I could not find any specs on the controller.

A quality MPPT controller has setting that can be changed to suit whatever you want to do. My advice is stick to a better quality unit. Indeed many cheap MPPT units are fake anyway and are really just PWM.

Jaahn

Whenarewethere · Guru

Some settings on my Victron MPPT 75/10 Bluetooth controller.

Victron MPPT 75-10 battery setup.jpg

Dick0 · Guru

Whenarewethere wrote:
Some settings on my Victron MPPT 75/10 Bluetooth controller.

Everywhere I look I find inconsistencies in default solar charge settings for LiFePO4 batteries.

For instance your Victron settings show Absorption 14.2V and Float 13.5V.

On another site Victron recommended Absorption 14.2-14.6V and Float 13.6V. (100ah battery).

Renogy recommend Absorption 14.4V and Float 14.4V. (100ah battery).

And yet another site recommends Absorption 13.6V and Float 13.5V. (100ah Battery).

My new Lithium Battery specs at Nominal Voltage 12.8V and Charge Voltage 14.6V. I am assuming, perhaps incorrectly, that Absorption should be 14.6V and Float at 12.8V.

How do you know what the correct settings should be?

confuse confuse confuse

My Epever solar controller shows default Absorption 14.5V and Float 13.8V.

Whenarewethere · Guru

I don't have lithium, just switched it to lithium for this image so people can see some of the options. You can adjust all the voltages & allow for temperature etc for lithium, AGM & Gel etc.

I have gel, also the 75/10 is a spare controller as I replaced it with a 100/20 as it was not large enough for my 120 watts.

Jaahn · Guru

DickO asked "How do you know what the correct settings should be?

confuse confuse confuse

My Epever solar controller shows default Absorption 14.5V and Float 13.8V."

________________________________________________________________________________________________________________

Hi DickO smile

My answer is always ask the battery manufacturer or look on their web site ! Not on a forum or the controller information.

Jaahn disbelief

-- Edited by Jaahn on Friday 2nd of July 2021 07:22:42 PM

Whenarewethere · Guru

I have never done any research on lithium voltages. Even all my Bosch tools I just plug them in & let Bosch decide what to do.

As far as my four 26AH Gel batteries I have simply left the MPPT on default. Bulk, one can see the voltage shift around quite a bit depending on the level of charge in the battery to squeeze out every last amp from the solar panels. Absorption is up to 14.4 volts.

I would not touch a cheap controller with two barge poles in series!

Mamil · Senior Member

I wouldn't get too hung up about the exact voltages, most batteries can accept a range, within reason. The important thing about a Lithium specific profile is that it should have temperature compensation to reduce charging voltage when it's hot, and switch charging off when fully charged rather than hold the battery at float for long periods of time, because Lithium don't like either of these things and it will shorten their life. Quality Lithium chargers will incorporate both these features, whether they are mains, DC/DC, or solar controllers. That's what those selling "drop-in" Lithiums don't tell you because they want to make it easy as possible for you to buy their products, and their warranty will be long gone by the time the effects of a poor charging regime start to show themselves.

-- Edited by Mamil on Saturday 3rd of July 2021 01:16:08 PM

Monty10 · Member

Thanks all for the advice.

My power station has an MPPT controller built in so I can bypass the blanket controller so all OK.

Cheers Monty

Whenarewethere · Guru

If you haven't done so, stick in an amp & voltage meter to see what's happening.

Brenda and Alan · Guru

Monty10 could you tell us exactly what the lithium battery you have is. I think this discussion is pointless at the moment.

Alan

Whenarewethere · Guru

He said which make & AH he has.

Maybe he doesn't want to do a teardown to see exactly what is inside.

Whenarewethere · Guru

I just looked at the specs. The inbuilt MPPT solar controller as they say is only 5amps.

One wouldn't want to put proper solar panels on it as you would probably cook it.

My Victron can output up to 11.3amps from 120watts of panels which can output up to 137watts under perfect conditions.

Monty10 · Member

Hi Whenarewethere,

I can see the power station MPPT controller is rated at 5A, but isn't this what the controller does, limit the charge being passed on to the battery to protect it from overcharging.

A novice with 12 volt system so any advice is welcome.

Cheers.

Whenarewethere · Guru

When I was designing my system I worked out 120 watts was enough for out needs & it still is & it has grown in capacity simply due to fine tuning.

I did a lot of research. 120 watts of panels depending on the efficiency has about 6.6amps output at 18volts.

Victron MPPT 75/10 controller states a maximum of 145 watts solar for a 12v system. Under run of the mill weather this is ok. Under perfect conditions with 145 watts of the panels I am using I could get up to 13.65amps out of the controller. But it cuts off at 10amps, so 3.65amps cannot be utilised.

But I think one would be risking damaging the 10amp charger putting 290 watts in & it only allows 10amps out on a 12v battery set up.

Could be wrong but I wouldn't do it.

So putting 120 watts of quality panels with up to 11.3amps potential controller output into a battery when a controller only had 5amp output could be asking for trouble.

Putting all the above aside. Isn't one of the key features of lithium to have a high rate of charging.

What is the point of having a maximum 5amp charge via 240v, 12v or MPPT into a 40AH lithium battery.

To me it simply says a crap product.

One would be better off buying the components. It's not that difficult to put them all in a box.

Whenarewethere · Guru

One of my compatriots setup. This 100AH lithium prototype I reckon will outperform anything off the shelf.

Lithium battery.jpg

kesa32 · Senior Member

Hi , what cells is he going to run ?

Whenarewethere · Guru

I don't actually know & this was quite awhile ago & he has seemed to have vanished from this forum unfortunately, as there were some great articles from this person.

Anyway, you can knock up your own set up if you are prepared to put a bit of effort in. I have thought about it myself. All I need is a Victron battery. I have the rest of the Victron hardware.

I have to put in a bit more thought, a bit like my 3 ARB compressors, air tank & mooistmo trap, which all clip in, mainly for maintenance, but could easily transfered.

The same principles could be used for a battery setup, plug & play a Victron setup! My car solar setup is pretty much plug & play with every component. A bit more to set up with Anderson plugs but far more easily adaptable in the long run.

I don't know why the above image vanished. Attached a new version edited from my computer (battery sitting on my paper recycling bins behind my garage wall)

Another compressor clips in in front, also air lines & electrically.

-- Edited by Whenarewethere on Tuesday 6th of July 2021 10:07:03 PM

kesa32 · Senior Member

Yes lve made my own awhile ago ( 280ah ) , l was just curious as to what cells were used in it
I've seen pics of your compressor before , looks good mate

VK2FJW · Veteran Member

This is what I have!

https://teambmpro.com/

https://teambmpro.com/products/high-amp-battery-management-system-batteryplus35ha/

https://teambmpro.com/products/odyssey-touch-screen-display-rv-monitor/

and 4 100 Amp Lithium batteries with BMS inside which is a must have otherwise the batteries won't last!

Cheers from Frank

-- Edited by VK2FJW on Tuesday 6th of July 2021 09:52:25 PM

VK2FJW · Veteran Member

Monty10 wrote:
Hi,
I have just purchased a Kings 120w Solar Blanket after reviewing the specs on the web site. However I was surprised to see in the user manual, when opening the blanket after purchase, that the solar blanket and MPPT regulator are not to be used to charge Lithium ion batteries. Stating that the MPPT controller is only suitable for Lead-Acid batteries.
Is this common for MPPT controllers?
Luckily I purchased the blanket to charge up a Companion 40Ah Rover Lithium Power Station with a built in MPPT controller to allow direct charging from the blanket.
Cheers Monty10

A lot of people are going to get burned because they didn't do their homework on Lithium Charging.

https://www.jaycar.com.au/20a-mppt-solar-charge-controller-for-lithium-or-sla-batteries/p/MP3741

https://teambmpro.com/products/high-amp-battery-management-system-batteryplus35ha/

It is not a simple plug and play unless you use the required addons to control the Lithium charging rates!

Cheers from Frank