Need help with settings for new batteries - PowerSafe SBS 170F

DIY
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1

Hello I need assistance figuring out settings for a system.

24V system:
Smart Solar 100/50 charge controller. Equalization off.
PowerSafe SBS 170F batteries

Data sheet on batteries says:
Constant voltage chargers are recommended. The acceptable float voltage
range is 2.27-2.29Vpc at 68ºF (20ºC) and 2.25-2.27Vpc at 77ºF (25ºC).
The temperature compensated voltage should not go below 2.21Vpc.

The recommended float voltage temperature compensation is:
Temperature F 50F 59F 68F 77F 86F 95F 104F
Recommended 2.33 2.31 2.29 2.27 2.25 2.23 2.21 Vpc
Minimum 2.31 2.29 2.27 2.25 2.23 2.21 2.21 Vpc

Question:

  • Can the charge controller function as a CC charger?
  • Absorption Voltage setting?
  • Float Setting?
  • Temperature Compensation Setting?
2

These are often called telecom batteries and thd settings you have are for the situation where the batteries are used as a back up power supply so they are kept on float storage for long periods, these are not the cycling settings where you discharge and recharge each day. Using a constant voltage charger does not work for daily cycling.

I have the Victron telecom batteries, equivalent to yours and are working well after 4 years cycling service using these settings. You will need to go into expert mode for the last 3 settings and these are optional, you could leave at default.

Absorption 28.8V
Float 27.2V
Temp comp -48mV/C (-26.7mV/F)
Rebulk 0.8V
Absorption fixed 4hr
Tail current 2A for each battery in parallel

If you have 4 batteries in parallel set tail current to 8A.

3

This is great. Thanks for the explanation. I do have a question about tail current. There will be 8 batteries per charge controller. Series/ parallel configuration. It would work out to 4 parallel sets per battery bank. So will the setting of 8A tail current still apply?

4

Adding batteries in series retains the same Ah as you have surmised, so 4 batteries parallel = 680Ah so tail current = 4 x 2 = 8A. I am running 690Ah (6 x 115Ah) and find 8A works well.

5

The place is not occupied daily. It is primarily weekends. Would you still recommend 4hr absorption if the batteries are not cycling daily?

6

If the tail current is set and there are no loads then this should stop absorption very quickly. When my boat is unused absorption lasts maybe 15 minutes. You may also consider changing your settings before you leave if you are concerned to 1 hour or even reducing absorption voltage.

7

Thank you for your assistance. So far everything seems to be working well.

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8

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