Lithium Batteries, who has them?

[dream4red]

Now you're going to tell us what sort of expenses we are up for?

Will it be time to trade the jayco for a battery system? No, I love our jayco, but recognise that it is a great product built to a price and only suitable for black top travelling.

Thanks for the information Terry, I am trying to keep up.

[T1 Terry]

Now you're going to tell us what sort of expenses we are up for?

Will it be time to trade the jayco for a battery system? No, I love our jayco, but recognise that it is a great product built to a price and only suitable for black top travelling.

Thanks for the information Terry, I am trying to keep up.

Maybe later Deborah, but this first one is more for those who have jumped in and bought a lithium battery without understanding the differences or for those who were about to jump in, just so they better understand what is needed and what is a waste of money being peddled by someone who really doesn't understand the needs of a house battery pack, very different to an electric vehicle battery pack, but more of that will be explained later.

T1 Terry

[homeless]

I have had mine for over 4years and a happy little chappy is me.

Regards
Brian

[BruceS]

Huh? Who's dinghy? lol
I'm still watching like a hawk Brian........ nope!... no little ones yet!!
Mothership goes on the slip on the 20th for some makeup & zincs!

[dapope]

We have 720w solar and 400ah of lithiums. I am about to add more solar to bring us up to around 1000w. This should enable me to run the air more often. I find if I leave our big inverter on, our current system struggles to get the power ereplaced in a timely manner, even without large power draws. I also want to be able to run the water heater element regularly, as this will help reduce gas consumption.
Like most people who have made the switch, I would never go back to lead acid through choice. Making toast for example, uses about 1% of battery capacity.
That takes relatively little time to put back in, even on a rainy day I have seen 6 amps coming out of the panels, enough to keep the fridges ticking along.
Neither of us are interested in particularly HAVING to be conservative with power use. We like our comforts too much.

[El Gringo]

Can we PLEASE NOT turn this into a benefits or otherwise of Lithium Batteries.

The thread title says it all, "Lithium Batteries, who has them"
If your happy with your system and believe others are dumb for not following your advice, then start your own thread.
This one is for those with Lithiums, or by extension those contemplating it, and wanting to hear from them as to their set-up, and even more particularly what is required for a long lasting set-up as per T1's recommendations.

So, Terry, how long are you going to keep us in suspenders?

Cheers,

[T1 Terry]

I promise we will return to the normal program this evening, internet permitting of course
Hopefully I've now split the off topic to a new topic, either that or I am now apologising for sending a lot of posts off to power the ether

T1 Terry

[T1 Terry]

More on putting some of the nonsense to bed:

The information relating to EV (electric vehicle) battery charging and BMS (battery management systems) is not the same for house batteries.
Yes, the cells can be the same and even from the same manufacturer, but the use pattern is completely different so the charging parameters are completely different. The capacity per cell and the number of cells in parallel ( + connected to + and - connected to -) is nothing alike so the balancing modules used in electric vehicles will not balance house battery cells effectively.
An attempt to explain why.
An electric vehicle relies on high voltage to create the high speed required from the electric motors, but not high capacity in each cell. The cell capacity in an electric vehicle is often only 40Ah, but 100 to 200 cells in series to build a battery pack to over 600v in some cases. As the capacity is so small it's important that all the cells are saturation filled, 3.6v is the general max voltage in any cell before the BMS board starts it's balancing action. The signal is sent back to the special BMS battery charger to limit charging to 0.5 amps, this equals the discharge capacity on the little BMS boards, so each cell is held at 3.6v till all the cells reach 3.6v, then the battery is considered saturation charged. When the EV is driven the current demand can be up to 1000 amps for a very short period, but generally around 200 to 300 amps is about the upper continual discharge.
Now compare this to a lithium house battery. The general voltage is 12v, 40 Ah isn't going to last long so more like 200Ah or 400Ah is required. How long would it take to balance the cells if one cell reached 3.6v so the charging was limited to 0.5 amps? The next question, does any of your battery charging systems have anyway for the little BMS modules to tell it to only charge at 0.5 amps? No they don't, so the solar keeps pumping in 20 amps or more, the cell at 3.6v is already saturation charged so any charge current will push the voltage higher, the little module can burn off 0.5 amps as long as the cell doesn't go over 3.6v, but with an extra 19.5 amps pushing the cell voltage higher the little module simply can't cope so it generally burns out. That's the end of the BMS for that cell and the cell voltage continues on climbing till the cell is destroyed.
Anyone trying to sell you an EV type BMS system for your house batteries simply does not understand how different house batteries and their use is compared to EV batteries and their use, so any advice they give you should be considered as advice suitable for EV batteries, not house batteries.

No doubt this one will cause a whirl wind of controversy and no doubt a number of attacks, but you can dispute the facts.

T1 Terry

[BruceS]

No, I don't think many on here have sharpened their arrows. I ALWAYS consider forums as a place for information that is available for digesting by everyone.
I think it's good that here on the forum we can just post up our thoughts and opinions and then it is up to us to decide which bit of info is for us.
Thankyou Terry and everyone for your contributions.

[T1 Terry]

The next instalment:
Parallel connecting 12v batteries to increase capacity is really asking for problems and seriously increases costs. Each 12v battery needs it's own cell monitoring system, then each of these must work together to control the charging system. Another problem is discharging. These batteries have extremely low internal resistance and as a result there is very little voltage drop at the battery terminals as the state of charge reduces, so any resistance after any one of the batteries in the group will reduce that batteries level of load sharing.
An example to try and show what I'm getting at. 4 x 100Ah 12v batteries connected in parallel, battery 1 has 500mm long leads to reach the power distribution point, where all the battery terminals join, battery 2 has 1mtr long leads, battery 3 has 1.5mtr long leads and battery 4 has 2mtr long leads. All materials have resistance, the longer the lead, the greater the resistance. Electricity is lazy, it will take the path of least resistance, battery 1 has the shortest leads, the battery voltage will remain virtually the same as the other 3 batteries till it is deeply discharged, so battery 1 cops all the work until it is deeply discharged, then its voltage will drop under load making the next battery in the series the path of least resistance, so battery 1 is deeply discharged, then battery 2 starts along the same path and the pattern continues.
Now we turn to the recharging side, battery 1 again has the least path of resistance so that will be the battery that charges first, till it's full, then battery 2 etc etc. The end result, battery 1 is worked very hard, battery 4 virtually offers no assistance until the other 3 start to show signs of serious damage resulting in increased internal resistance.

There is a better way, more on that tomorrow

T1 Terry