L-A controller to a lith battery

[DonTom]

What happens, I mean what is the big disadvantage of using a lead-acid only solar controller on a lith battery?

I just today opened the box and I discovered my NIB SamplexPower MSK-90 controller has no lith mode. I can change it when I get home, if it's worth the trouble. But what happens when it is used as is on a lith battery?

-Don- Everglades Nat'l Park, FL

 

[solarman]

this controller is a PWM type and has no programmable setpoints.

typical setpoints for mppt with drop in lithium are.

Absorb = 14.6 volts
Float 13.5 volts
EQ = OFF

looking at the spec, it would appear you could use it for a drop-in for a short period.
the absorb is a bit low and the float is a bit high but would work.
the EQ voltage is low and is tailored for AGM. one would not normally use EQ with AGM unless
the battery mfg defines it.
usual FLA profile will undercharge and normal EQ will stress BMS somewhat..

I suggest you swap out for a MPPT type with programmable voltages and/or one with a lithium profile.

pdf manual for your controller is here.. Manual

 

[Isaac-1]

Really depends on the specific charging voltages and transition points of that model. ps. after reading the manual I am concerned it will not work well for you as it will only stay in absorption mode for 2 hours, then moves to float, and will not go back into absorption until the voltage drops below a fairly low setpoint for LiFePo4

 

[DonTom]

Thanks, all. I won't use it on this trip. I really only wanted the solar for my added lith battery. But I can just run the genny a bit more.

But this RV has two stock 6V L-A batteries in series, I could use it there. But they have their own 100W solar on the roof anyway, but the more the better.

I will make sure I get a controller that can work with either L-A or lith. Or I will just get a lith only controller and keep this one. Easy enough to swap.

-Don- Everglades Nat'l Park, FL

 

[DonTom]

I somehow forgot my original intent with that solar. Until today.

That was to use solar on both, the stock L-A as well as my added lith battery. 100W on each.

So that solar panel I asked about was really for the L-A batteries in this RV and the plan was to take the portable solar panel from my old RV and put it in this one before this trip. That one does both, can select lith or L-A, but will only use that one with the lith.

So I already have everything needed, I just forgot to take the solar for the lith before this trip.

But perhaps I will buy another anyway, then I cannot forget as I will leave it in this RV. And if I bring the other, I will then have 200W of solar for my added 300 AH lith battery in this motorhome.

I used the solar on my L-A today. Somehow I forgot this RV still has and uses the two stock 6V L-A batteries.

-Don- Everglades, FL