Reply from Calira re Lithium charging

jagmanx

Full Member

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1,376
I have a Calira EVS 36/20 power management unit

I briefly considered Lithium but have gone for 2 x 100AH "Normal batteries" much cheaper at just under £300

I enquired of the German manufacturers and got this reply

Many thanks for your inquiry.
The EVS 36/20 has a battery charging curve IUoU.
The final charge voltage is 14.4 volts and the trickle charge voltage is 13.8 volts.
You have to clarify whether the BMS of the desired BLiFePo4 battery allows this


Not conclusive
However I also have a pdf of the manual if anyone wants it
 

Okta

Full Member

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437
Li doesn’t need all the phases of IUoU but I wouldn’t think it would do any harm. 14.4V and 13.8V look ok. Might not get a 100% charge on some Li makes but a few % less does no harm.
 

jagmanx

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1,376
The reply from Alpha was more conclusive
Partly due to Solar panel Controller.

Your Banner battery there has lasted well and would recommend sticking with that type of battery. Dropping down to lead-acid technology there would result in batteries being not as long-lasting.
Lithium is not an option here as you have pointed out as your whole charging system would need to change
My advice would be top fit two new AGM batteries. You need to bear in mind that your charger will work harder and longer to charge two batteries than the single unit you have but at 20a output will be fine (10amps per battery)
 

jagmanx

Full Member

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1,376
Li doesn’t need all the phases of IUoU but I wouldn’t think it would do any harm. 14.4V and 13.8V look ok. Might not get a 100% charge on some Li makes but a few % less does no harm.
Thanks Okta but as you see in post #3 another reason !
 

nickvanbitz

Full Member

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109
Depends on who's lithium and the BMS itself. Also the rate of charge current output based on the size of battery bank, as Lithium do not tapper off when being charged and will suck up any constant output, unlike conventional batteries which will naturally back off as they are being charged.

As long as the Absorb and Float voltages are to the manufacture spec of the Lithium and you are reasonably within 1/5 of the rated output of your mains charger to the total ah of your battery bank (i.e 100ah Lithium Battery, so 18-20A mains charger), then there should be no long term damage to either the Li or the mains charger.

The biggest oversight is mainly from engine to leisure charging, as I have so far not come across any Lithium that doesn't require some form of DC-DC/B2B Charger.
 

jagmanx

Full Member

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1,376
Depends on who's lithium and the BMS itself. Also the rate of charge current output based on the size of battery bank, as Lithium do not tapper off when being charged and will suck up any constant output, unlike conventional batteries which will naturally back off as they are being charged.

As long as the Absorb and Float voltages are to the manufacture spec of the Lithium and you are reasonably within 1/5 of the rated output of your mains charger to the total ah of your battery bank (i.e 100ah Lithium Battery, so 18-20A mains charger), then there should be no long term damage to either the Li or the mains charger.

The biggest oversight is mainly from engine to leisure charging, as I have so far not come across any Lithium that doesn't require some form of DC-DC/B2B Charger.
THanks
Having read the Calira document it appears that it might well do the job as it Automatically switches between the batteries.
So in some senses Split charging

However I have settled on a pair of AGM batteries.
 

nickvanbitz

Full Member

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109
Having read the Calira document it appears that it might well do the job as it Automatically switches between the batteries.
So in some senses Split charging
On mains charging maybe, but certainly not when you are driving along. The connection between engine and leisure will be done with relays soldered into the PCB board of the Calira unit, with very simple cables that simply just put the engine battery in parallel to the leisure battery bank when the engine is running. This isn't suitable to deal with any Li that I can think of, as there is no ability to adjust the voltage transferred from the alternator to the correct amount required, via the split-charge relay to the lithium, plus there is no way of restricting the current flow either.
 

jagmanx

Full Member

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1,376
Ok,
As you realise I have gone for normal batteries because as you imply the Calira unit will not correctly supply Lithium.

I am very happy with the Unit as it will charge the EB from solar once the LB (or Bank) are charged

Working off EHU is fine and when running the alternator does both Batteries and the Fridge.
I am sure there are more sophisticated systems with proper B2B or Split charger or whatever but it works for us and is simple...I like simple !
 
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sket123

Free Member

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However I also have a pdf of the manual if anyone wants it
I'm having issues with a Calira 30/20. Not quite the same unit but the pdf may be helpful. Also I'd be very grateful for the email to contact the company. I thought they had gone out of business.

Thanks in advance.
 
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