Batrium Longmons - Active Balancing?

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Ok, I have another question, or thought for you all.This is me thinking out loud really;)

Since I got my LiFePO4 cells I've been busy researching the chemistry while running my 12 volt system.

There is not a massive amount of info out there and a lot of it can be conflicting I've found.


The main focus of discussion around them is over charge/ discharging and balancing cells.

My experience has been my cells are all really well balanced, even at higher and lower voltages but there are a couple of cells that discharge to a lower voltage than the rest.

The other thing is that unlike Li Ion you can't rely on voltage for true indication of state of charge. The cells may be reading 3.45 volts per cell under charge, then take away the solar and they will soon settle to around 3.30v.

These are thereasons I have purchased abms.

The next issue is finding a charge controller with suitable charging profile for LiFe chemistry. Some say it's as easy as restricting voltage to around 3.65v per cell and all is good...But is it?

This brings me to my question...I have only found a fewthat some say are suitable and a couple that are supposed to be designed around these batteries, one being the Australian designed GSL electronics GSL MPPT60-1L. Does anyone have any experience with these?

The other option I've been considering is either the Eltek flatpack 2. Or the Elcon TC48v charger both of which I think can be controlled by the batrium system.


Would be great to hear your thoughts
Cheers
 
New member...still working on building my packs. If I'm not mistaken, the longmons, etc. simply burn off energy as heat to prevent over charging (passive balancing). Wouldn't it be better to use an active balancer to minimize wasted energy? Does Batrium have an Active balancing system? In case I'm confused, it's my understanding that an active balancer will push the excess energy to the cells that need it, instead of just converting it to heat.
Thanks,
Will
 
Willburk97 said:
New member...still working on building my packs. If I'm not mistaken, the longmons, etc. simply burn off energy as heat to prevent over charging (passive balancing). Wouldn't it be better to use an active balancer to minimize wasted energy? Does Batrium have an Active balancing system? In case I'm confused, it's my understanding that an active balancer will push the excess energy to the cells that need it, instead of just converting it to heat.
Thanks,
Will

Will you are correct - Longmonsburn off energy, thus potentially 'wasting energy' that said there is so many more levels to that statement.

1. Cold climate and it's bad to charge/discharge your batteries when they too cold, no problem program your Watchmonto heat your cells first!
2. Transfering energy from one to another takes energy in its self.
3. How do you protect a cell once it's over charged and there is nowhere left for that excess to go?
3. If a lead gets damaged in your 'active balancing" and it stops balancing & how do you tell there is an issue? What happens if you don't see it (referringto the 1S units and probably others)
4. Active balancers (again 1S units) give a rather large sense of false hope (i hope they are working)

Most active balances I've seen have been nice and cheap and only balance, and haven't had experience with the expensive ones but they are more expensive per feature than Batrium Systems.

It is a matter of what your needs/budget is -

I was a HUGE bah ! never need that but you know what, at a glance, I can say YUP, i can sleep!

Hope that didn't come out a pure babble... :)
 
I was also a bit against "passive" as in wasting energy but in th elong rung.... My big bank of 80+kwh only balanced the first 2 weeks. And the weeks after that. (Almost 12 now) i have not wasted much at all... Not as it would matter at all. it would most likely save 100 time more by changing inverter than to care about the wasted energy due to balancing.

When you have to balance that much that you care for the waste it can be due to 2 reasons:
1. You have cells discharging way to much and you really need to look into the packs
2. You have uneven packs from start and want to balance low end and not just top end. Though waste once again and its better to just fix your packs.


Yes, there are situations when active balancing is a good supplement. Think about places where you cannot serve the packs often. Then you might want to transfer energy from high capacity units to low capacity units when you getting low on energy on some.... This is when the active part is very very good to have. BUT it cost alot initially! for us DIY people i think its better with wasting the energy and if so look at how you can balance your packs from start or perhaps go with a more efficient inverter or charger! That could save you 1000 times more energy! :)


My 5 cents.
 
Also - losses are everywhere in our systems - I bet I lose more 'energy' in the cables between my panels & charge controller than I ever would balancing.
 
Thank you both for the info. Curiosity: has anyone calculated the amount of energy wasted by their mons in an average day? They only burn about 4-8 watts, right?
 
Don't have to 'calculate' lol it'll tell you :)
 
I don't even have to math to see what cell should be replaced next :)


image_ouobhl.jpg
 
As peter said . The software will tell you how much have been wasted.


And then most likely the problematik one is the one not being balanced. And as peter said. Losses in cables, fuses and even worse the inverter or charger will be 10 times more. Especially if you use mpp Products.
 
Awesome chart! Do you know the time frame covered? That's a good point, daromer. Thanks for all the videos hbpowerwall, you have inspired me.

P.s. I love the blue cell color scheme.
-Will

-Been riding a Zero DS (e-motorcycle) for the last 3 years but want to setup an off-grid solar power storage and charger system for it. Currently moving across the US, but can't wait to get started.
 
Above was last day but you can get out daily reports of it as well.
 
The data you can pull will entertain a mathematics professor
 
I like it and have even asked them to include more :p
 
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