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svans avatar image

Charging arbitrary lithium chemistry and voltage with smartsolar

I understand that the SmartSolar chargers have a built-in profile for charging LiFePO4 batteries, but I'm wondering if that profile merely represents a set of values that can otherwise be set arbitrarily to charge an "arbitrary" battery. For instance, a lithium cobalt battery with a voltage that is not a multiple of 12. I'm also not entirely clear on how to select the bulk and float voltages for this application. I understand that absorption charging should not be used and can be disabled by setting absorption time to 0. Should bulk and float voltages be set to the same value of e.g. 4.2V per cell?

Additionally, is it possible to use the SmartSolar in place of a BMS by controlling a sufficiently rated relay from the load output? In theory this should provide over-discharge protection, over-charge protection, and cold charging shutoff. Over-current protection can be provided with a fuse. Are there any other functions that a BMS would provide?

Thanks!

MPPT - Solar Charge ControllerLithium BatteryBMSchargercharging
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3 Answers
RTSmith avatar image

Svans download the connect app software it lets you view the configuration / user settings available in demo mode for many devices. You might see the settings to answer your questions. Its available here. https://www.victronenergy.com/support-and-downloads/software


There is also a guy on you tube who has configured one for Lipocobalt to run various devices his video is here, https://www.youtube.com/watch?v=P77IY7uhZvc&t=155s i have put a message to him asking him what his settings are but so far no reply. You can see them at 2min.38 into the video.

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thanar avatar image

Indeed, you should also use a proper BMS that would work at cell level. However, the question then is, if the BMS would disconnect the battery due to a cell going over or under a threshold, would that damage the SmartSolar unit?

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AllEletric avatar image

The SmartSolar would only provide over-discharge protection at battery level ie, 11.2v.

Really you need over-discharge protection at cell level ie, 2.8v as cells could be out of balance.

imagine a 4s pack was at 11.2v but the cells were 2.8,2.5,3.0,2.9 the smartsolar would not see this.

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