Getting the Most out of your Silicon Dioxide (SiO2) Batteries – Charging Instructions

The Charging Parameters for Lead Crystal/SiO2/Silicon Dioxide Batteries are a bit different than regular lead acid batteries. To Optimize your charge efficiency, if you can, it is better to manually set the charging references.

The State of Charge chart is for zero or minimal load on the batteries, if there is a load on the batteries, then the voltages would be lower.

State of Charge Parameter for EFSN SiO2 Batteries

State of Charge Parameter for EFSL SiO2 Batteries

Bulk/Absorption Charging voltage range is 14.4V – 14.7V, with 14.6V optimal.
Float Charging voltage 13.5V – 13.8V.

For SiO2 Batteries, the Maximum/Optimal Charging Current is 25% of Ah capacity. This can be expressed as a 0.25C, C/4, or 4-hour Charge Rate.
Charging at lower current is fine, but these batteries actually charge more efficiently at the maximum rate. This also minimizes run time for a generator, and reduces fuel use, and reduces RV and boat docking time for shore power AC charging.

When the battery is fully charged, there is often an initial “surface charge” voltage normally starting at around 13.5V with no load, and will stabilize at around 13.05V after 4-6hrs. Or you can run a small load on the battery for a brief period to dissipate the surface charge for a more accurate voltmeter reading. This is common with most lead-acid batteries as well.

This should help you fine-tune your charging and monitoring systems to get the most out of your silicon dioxide/SiO2 battery.

Please feel free to contact us with any questions!

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  1. Hi,
    I have a truck camper with 400w solar panels on the roof and a 40 amp solar controller currently wired to two trojan acid batteries. I was wondering if your sio2 batteries would be ok to just replace them with or if my solar controller would need to be replaced or configured as well? I have an srne solar charge controller if that helps!

    • Yes, you can do a direct replacement of the Trojan batteries with SiO2 batteries. If you have an SRNE charge controller, these are easily programmed for optimal charging of SiO2 batteries. You will not need to replace your charge controller.

      SeeCharging your SiO2 Batteries for the best charging parameters for your reference. If you decide to purchase the silicon dioxide batteries, I can send you specific directions for your charge controller model.

  2. Many RV converters (chargers) have a float/storage voltage of 13.2 VDC. The voltage jumps to 14.4VDC if charging is required.
    Would this float voltage be a problem?

    • No it would not be a problem. The SiO2 batteries don’t really need a float charge, so when the voltage drops enough to engage a 14.4V bulk charge then the batteries would fully charge at that point. The float charge is primarly to prevent sulphation, which is not an issue with SiO2 batteries.

  3. I have a Smart 4 Stage PWM charger for my solar setup that has selectable battery type settings as follows; Deep cycle Sealed, Gel, Flooded, and Lithium battery. Would this charge controller be compatible and what would be the setting for your batteries to get best performance

    • If you have the ability to program your charge settings, yes, you can use temperature compensation. However, these batteries are not as sensitive to temperature as other battery chemistries.

  4. Hi, I have an older Progressive Dynamics Converter that charges at 13.6V / 55 amps. Is this voltage efficient for Si02 Batteries ?

    • This is too low of voltage for efficient charging. You would need to use a separate battery charger to ensure full charging of the units. We have a 20A AC charger that is optimized for these batteries.

    • Hi, I have a Renogy MPPT 40A charge controller. I’m trying to set the inputs properly. It seems to have “‘maxed” at 13.5/13.7 V but my display says this is 88% of my battery capacity. What should the final voltage be? And what parameters should I be setting on my charging controller?


  5. Hi

    “For SiO2 Batteries, the Maximum/Optimal Charging Current is 25% of Ah capacity. This can be expressed as a 0.25C, C/4, or 4-hour Charge Rate.”

    Since I have 4 batteries of 100ah each (400Ah total). Does this mean that I need to set my maximum charging current to 100?


  6. Will SiO2 batteries work as a starter battery and deep cycle in a dual battery Diesel truck? I often run a 12V fridge in my truck which isn’t very good for a starter battery. I have solar that I can use to finish off the charging if the alternator voltage is too low.

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