Lithium batteries and new solar charger

[Slownsy]

I am replacing my 4 6V batteries I think 2 lithium, have never been impressed by the 30A PWM charger for my 600W solar, probably my fault for using 8 avg wire on a 9m run. Thinking if I get a Victron 100/75 MPPT controller I can go parallel and series for 24V and have less voltage drop and hopefully better charging, and also maybe adding 2 more panels. What say you.
Frank.

[full_mosey]

BFL13 wrote:
Still no answer 😞

So if 10v is true zero and is 100AH down for the BB 100AH battery like it says, then people are fooling themselves thinking it is really a 120AH batt so they are not really going that low all the way to zero.

We can't know what is true unless we know the individual cell's specs. I can only imagine where you got the idea about 'true' zero.

With the drop-in packs, all you will be able to observe is the range of Voltage and rates of charge and discharge that are controlled by the BMS. The BMS is set up to enforce certain Volt, Amp, and Temperature limits inherent to the chemistry of the cells inside. What you are getting is a long warranty at a price. The drop-in's BMS will do its best to prevent you from using that warranty by denying you access to those cells.

HTH;
John

[Slownsy]

SV K thanks, I will get the new batteries first, and will have to go to MPPT before I can go in series .
Frank

[SV_K]

Hi Slownsy,

As you have not purchased the controller yet why not run all the panels in series? I run 900w at 115v to a Victron 150/60 thru 12m of 10ga. Victron has a deep product line so I am sure once you get your volt tally you’ll be able to find the right controller. The ability to adjust via bluetooth is great(as long as you buy the Victron controller with that option or buy the bluetooth dongle to add to a non BT Victron).

A nice option with the Victrons is the ability to set the Float Tail Amps, allowing me to set the Tail Amps to match my approx. hourly usage. Not really necessary, but nice nonetheless.

[BFL13]

Slownsy wrote:
I am replacing my 4 6V batteries I think 2 lithium, have never been impressed by the 30A PWM charger for my 600W solar, probably my fault for using 8 avg wire on a 9m run. Thinking if I get a Victron 100/75 MPPT controller I can go parallel and series for 24V and have less voltage drop and hopefully better charging, and also maybe adding 2 more panels. What say you.
Frank.

What panels do you nave now? Six 100s? As in two more of what so we can see the series-parallel and not go over the total Voc limit of the controller and what wiring would work best.

[Slownsy]

Could we please keep to the original question or discussion, and start another tread somewhere about flooded, agms, Battlehorn and other non related charging matters,
Thanks Frank.

[BFL13]

My 2025 Trimetric monitor says this:

"The “amps” or “watts” display measures the rate of energy going in or out of your batteries
so you can check your charging systems, and also to see how much energy each of your appliances use to
help you conserve energy."

Is "energy" being used correctly there?

[BFL13]

Here's another one for a 100AH AGM:

" And the pure lead plates mean 2 times the overall power and 3 times the life of conventional batteries, up to 400 cycles at 80% depth of discharge!"

https://www.odysseybatteries.com/pc2150t.htm

What do they mean by "power" ?

[BFL13]

full_mosey wrote:

BFL13 wrote:
....

But resting full is 13.6v so 100 x 13.6 =1360 watt hrs so it is confusing? Whatever, Battle Born claims the 100AH batt has "2 to 3 times the power of the same size lead acid" batt.

"Power" meaning watts? Watt hrs? meanwhile a 100 AH 12v FLA has a resting voltage of 12.73 when full so that is 1273 watt hrs.

Beats me how 1360 is 2 to 3 times 1273. I am told this would all make sense if only I owned LFPs myself, but do you need some kind of New Math too? 🙂

Easy, Watt-hours are energy, not power.

Which one can produce all of its energy, 100Ah, in the shortest time?

Put another way, LFP has the same size fuel tank but more horsepower and can work faster.

If the FLA is pushed to work faster than 5A, less work gets done. The LFP doesn't care because there is virtually no sliding scale of work produced based on how slow or fast it gets done.

HTH;
John

Sounds a bit like this from the Relion LFP blurb:

--Constant Power-- Full power available throughout discharge. Voltage does not drop like lead-acid.

Are they using "power" correctly? I can't keep the physics stuff straight. Grade 6 math I can do, but Physics was in Grade 7 I guess 🙂

The high discharge rates with LFP (and SiO2) table does show the time it can do the high rate is shorter the higher the rate somewhat like an FLA has less capacity in AH with a higher amp draw.

The 100AH SiO2, eg can do 5 amps for 20 hrs, 62 amps for 1 hour,105 amps for 30 minutes, and 175 amps for 15 minutes, all with an end voltage of 9.6 volts

[full_mosey]

BFL13 wrote:
....

But resting full is 13.6v so 100 x 13.6 =1360 watt hrs so it is confusing? Whatever, Battle Born claims the 100AH batt has "2 to 3 times the power of the same size lead acid" batt.

"Power" meaning watts? Watt hrs? meanwhile a 100 AH 12v FLA has a resting voltage of 12.73 when full so that is 1273 watt hrs.

Beats me how 1360 is 2 to 3 times 1273. I am told this would all make sense if only I owned LFPs myself, but do you need some kind of New Math too? 🙂

Easy, Watt-hours are energy, not power.

Which one can produce all of its energy, 100Ah, in the shortest time?

Put another way, LFP has the same size fuel tank but more horsepower and can work faster.

If the FLA is pushed to work faster than 5A, less work gets done. The LFP doesn't care because there is virtually no sliding scale of work produced based on how slow or fast it gets done.

HTH;
John

[BFL13]

I wire and fuse for what my inverter is likely to ever do, not what it can do. If it ever got loaded to more than what I wired it for, the fuse would blow. Works for me.

[time2roll]

Slownsy wrote:
Why do the Magnum call for 0000.

voltage drop and surge performance.

[Slownsy]

Ok the speech from manufacturer is charge to 14.4-14.6 then float at 13.3-13.8V.
The BMS is set to cut out at 11.6V and above 15.0V the 11.6 threshold equates to about 2-5% remaining battery capacity.
The manufacturer recommended to connect loads and charging with 00 cable but my 3000W Magnum hybrid inverter charger specs is for 0000 which is what I currently have but may not be able to fit to batteries and BMS. I have never used over 200A as per my display running microwave fridge etc not HW or air conditioner and according to cable chards 00 can handle 200A for quite some distance. My inverter to batteries and back no more than about 2m. Why do the Magnum call for 0000.
Frank..

[BFL13]

The OP says he is getting two 100AH LFPs with usable of 200AH if he runs them down, but he has indicated he knows to run them down to 20% normally, and make his usable 160AH vs whatever his four 6s have for usable. depends on the AH size of the 6s. Some are 190AH, some are 210AH mine are 230AH, some are more. the OP said he could get more like the same usable with three LFPs that way.

Just to make more trouble 🙂 The OP says his batts are rated at 1280 Watt hrs, which is from 100AH x 12.8 v (their "nominal" voltage)

But resting full is 13.6v so 100 x 13.6 =1360 watt hrs so it is confusing? Whatever, Battle Born claims the 100AH batt has "2 to 3 times the power of the same size lead acid" batt.

"Power" meaning watts? Watt hrs? meanwhile a 100 AH 12v FLA has a resting voltage of 12.73 when full so that is 1273 watt hrs.

Beats me how 1360 is 2 to 3 times 1273. I am told this would all make sense if only I owned LFPs myself, but do you need some kind of New Math too? 🙂

[time2roll]

I think it is four cells in series to make 1 battery at 280 Ah usable.
Still more than 220.

[3_tons]

“Wouldn't that be more Ahs that 4 x GC2's at 440Ahs?”

That’s a great point...two 6v GC’s in series at 50% DOD = 110 usable a/hr, x 2 (4 GC’s) = 220 usable...

Four LiFePo4’s @ 280a/hr, x 2 = something south of 560a/hr usable...

“But, but, but” lol !! 🙂

3 tons