Correct Battery/Charge Controller Usage Question

[wcc1414]

How do I set the correct parameters for my batteries to drain all the way to 10% and then start putting energy back into the batteries?

Current parameters and specs:

Victron Charge controller MPPT 150/100

3x HQST 190-watt panels

2x 200 amp hour lithium-ion batteries from SOK

Absorption Voltage: 14.4

Float Voltage: 13.6 (I don't need this I'm told? If so, how do I remove it altogether? Cause when I enter in O the default is 8V)

Charged voltage: 13.6v

Yesterday when I reached a 100% SOC with the solar, the controller switched to absorption mode which trickled down and switched to float, by then it was the end of the day.

Ran my Maxx air fan all night, and woke up to a 95% SOC but the charge controller was in bulk mode. How do I prioritize the batteries to be used first before being switched back on to bulk mode, as I understand this is the correct usage for the batteries?

Thanks for any and all help!

 

[12VoltInstalls]

If you only used 5% overnight that’s fantastic imho.
I wouldn’t force them to 10% constantly.

 

[littleharbor2]

How do I set the correct parameters for my batteries to drain all the way to 10% and then start putting energy back into the batteries?

Current parameters and specs:

Victron Charge controller MPPT 150/100

3x HQST 190-watt panels

2x 200 amp hour lithium-ion batteries from SOK

Absorption Voltage: 14.4

Float Voltage: 13.6 (I don't need this I'm told? If so, how do I remove it altogether? Cause when I enter in O the default is 8V)

Charged voltage: 13.6v

Yesterday when I reached a 100% SOC with the solar, the controller switched to absorption mode which trickled down and switched to float, by then it was the end of the day.

Ran my Maxx air fan all night, and woke up to a 95% SOC but the charge controller was in bulk mode. How do I prioritize the batteries to be used first before being switched back on to bulk mode, as I understand this is the correct usage for the batteries?

Thanks for any and all help!

Why do you want to be drawing your bank down that far?
You can skip charging days on some controllers. You can shut down your controller manually if needed.
You will get longer life from your batteries if you shallow cycle them but if you want to deep cycle them you will find out soon enough if you can recharge them the following day. As time goes on you will find how balanced your system is and whether you need to add more solar, batteries, controller capacity, etc.

 

[wcc1414]

Why do you want to be drawing your bank down that far?
You can skip charging days on some controllers. You can shut down your controller manually if needed.
You will get longer life from your batteries if you shallow cycle them but if you want to deep cycle them you will find out soon enough if you can recharge them the following day. As time goes on you will find how balanced your system is and whether you need to add more solar, batteries, controller capacity, etc.

I don’t necessarily want to. In my time trying to understand the topic, I thought the correct way to use the batteries would be to let them discharge to around 10-20% and then charge them up to 90%-95%

Are you saying it’s normal and acceptable to keep them close to 90-100% SOC on a regular basis?

I was under the knowledge it was healthy to let them cycle.

 

[12VoltInstalls]

Well I’d probably do 80-90% myself

 

[12VoltInstalls]

was under the knowledge it was healthy to let them cycle.

Lead acids like a good recharge now and again but not extreme like that. Your lithium batteries will hold 80% charge and not care for 35000 years.

 

[Solargmc]

Why do you want to be drawing your bank down that far?
You can skip charging days on some controllers. You can shut down your controller manually if needed.
You will get longer life from your batteries if you shallow cycle them but if you want to deep cycle them you will find out soon enough if you can recharge them the following day. As time goes on you will find how balanced your system is and whether you need to add more solar, batteries, controller capacity, etc.

Can you explain more when you say "you'll find out soon enough". You mean draining a battery too much?

 

[littleharbor2]

Can you explain more when you say "you'll find out soon enough". You mean draining a battery too much?

Meaning will your system be capable of recharging your bank from 10% to 100% in the course of one solar charging day. If it can't then you will need to enlarge your charging capacity or not use so much power on a daily basis.

 

[wcc1414]

Meaning will your system be capable of recharging your bank from 10% to 100% in the course of one solar charging day. If it can't then you will need to enlarge your charging capacity or not use so much power on a daily basis.

This does make sense now under new knowledge. I was just under the impression to maximize the life of a battery, even lithium, it was better to run them in cycles 90-10 to 10-90 to 90-10 and so on.