Lithium-ion and solar panel life cycles?

[jaycocreek]

With a lithium-ion battery is it better to run it down or keep solar plugged in?

I have an Engel compressor refer/freezer that draws 36-37 watts when it runs..I also have a portable 100 watt solar panel that puts out on average about 65 watts..It has been as high as 81 watts if I take the time to aim it right..

My question is,when I hooked it up,it quickly charged the battery to 100% with the Engel running and then it showed 0% input from the panel for a while then back to 64-65 watts input then 0%..

Is this method better or worse for battery cycles/longevity than running the battery down then charging it?

Completely new to solar and trying the portable solar for now...So I am a solar dummy of sorts for the time being..LOL

[pianotuna]

Steve,

$455 per 100 amp-hours with 80% usable. Cost per cycle may be lower than GC.

1500 cycles to 20% state of charge, or 2800 cycles to 50% state of charge.

Surge capability is much superior to LI, so they are ideal for large inverters.

[StirCrazy]

pianotuna wrote:


I'm going SiO2 instead. They can survive being discharged to stone bone dead 620 times. Of course, that is not recommended. They appear to be better than LI in every category except for weight.

This solar series in plain English may help: https://freecampsites.net/adding-solar/

what kind of price do they carry out there compared to lead acid. I have 470AH of GC batteries that need to be replaced soon in my 5th wheel.

Steve

[pianotuna]

noteven wrote:
It looks like the SiO2 Grp 27 size 100ah Soneill battery has a max charge rate of 25amps

This would make them well suited to solar vs Big Amps via a generator?

Yes, but, anyone who boondocks would want more than one. I'll be planning on four--but might just jump to six, or seven. I may put one in the Chassis as well. But 4 would want 100 amps if they were hungry.

The other issue is the "big amps". So far as I am aware 100 amps @ 12 volts is about the limit for converters. So the generator would be loaded to about 1400 watts (boost mode from a 100 amp boondocker converter) maximum.

[noteven]

It looks like the SiO2 Grp 27 size 100ah Soneill battery has a max charge rate of 25amps

This would make them well suited to solar vs Big Amps via a generator?

[pianotuna]

2oldman,

Similar in weight to lead acid--I think 70 lbs for a 100 amp-hour jar.

[2oldman]

pianotuna wrote:
What sold me, other than cold weather performance, is the SiO2 can be discharged to stone bone dead 620 times. That flabbergasts me.

That's amazing. My Li pack has had 5 discharges (BMS stops it at 42v). Then you have to 'reboot' it by disconnecting it from any draw or charge.

I can't find the weight of the SiO2 jars.

[MrWizard]

Yes... That's Phenomenal

[pianotuna]

MrWizard wrote:
I did a quick look on Amazon,
There it seems process are more like 1/2 of Lithium not 1/3
Still that is a big savings

https://azimuthsolarproducts.com/product/12v-100ah-sio2-battery/

$449.12 USD for a 100 amp-hour 12 volt jar. They do offer a small discount starting at 3 units. I'll probably want five, and wish I could afford eight. (seven house, one starting).

Prices are dropping on Li batteries.

What sold me, other than cold weather performance, is the SiO2 can be discharged to stone bone dead 620 times. That flabbergasts me.

[MrWizard]

I did a quick look on Amazon,
There it seems prices are more like 1/2 of Lithium not 1/3
Still that is a big savings

[pianotuna]

Lwiddis wrote:
I wish Don would buy those batteries so we could have a real world report. I’m hoping for great results.

* Cheerfully accepting donations.... * LOL

I will certainly do a report once I have them.

[time2roll]

Follow the manufacturer specifications and you should get 20+ years from both.

[Ro_n_Joe]

pianotuna wrote:
Hi,

For greatest longevity Li doesn't like to be charged above 90% of full, nor discharged below 40%, especially for storage.

The deeper the discharge the fewer total cycles. Attempt to not go below 20%.

All the recommendations I find are charge to 90% before storage. Refresh the charge from time to time.

Do not store below -4 f (-20 c).

I'm going SiO2 instead. They can survive being discharged to stone bone dead 620 times. Of course, that is not recommended. They appear to be better than LI in every category except for weight. The SiO2 are similar weight to lead acid. They can be used and charged at -40.

This solar series in plain English may help: https://freecampsites.net/adding-solar/

Thanks for posting. 1st time I've heard of these and after a quick research on them, it looks like an option when I need replacement.

[noteven]

pianotuna wrote:

noteven wrote:
Suggest you call your battery manufacturer for advice on correct charging with low current.

My research has discovered Li-FO4 batteries can discharge and charge at high rates, are happy to sit partially charged, and are good for 3000-4000 cycles to 20-30% when operated and stored properly. It makes them particularly suited for generator and vehicle alternator charging with the right equipment.

SiO2 is also happy to not be charged. Storage time is 2 years. They require NO special equipment to charge and do not require cell balancing devices. Maximum discharge rate is 9 C. 1/3 the price of Lifepo4

Silicon dioxide looks better suited to the pummeling by the western Canadian climate.

[theoldwizard1]

red31 wrote:
I let the BMS and CC do their thing.

In general, I agree, but I also agree with this

pianotuna wrote:
For greatest longevity Li doesn't like to be charged above 90% of full, nor discharged below 40%, especially for storage.