Volthium 25.6-200-RH-3U-C

Also see our Finding Happiness with Lithium-Ion article, explaining the care and feeding of these batteries.

The 25.6-200-RH-3U-C is a battery for 19″ rackmount in 3U height made by Quebec-based Volthium. These batteries are meant for a modular system that can be made to fit any need, by stacking as many as needed.

The Volthium 25.6-200-RH-3U-C (heated) is a 24 Volt 200 Ah (5.12 kWh of stored energy) battery. These batteries are meant for mounting in a standard 19″ rack. Any sturdy 19″ rack will work, such as those from Tripp Lite or StarTech. The battery is only available with a build-in heater. The heated battery allows safe discharge to -20C and charging all the way down to -25C (-13F)! The heater automatically kicks in when the BMS sees a charging Voltage and the internal temperature of the battery is -7C or lower. No user-interaction is needed.

Up to 32 units can be stacked in parallel, for a total of 24 Volt @ 6400 Ah, storing nearly 164 kWh in energy (with 100% of it usable)! The BMS of each unit talks to the others, so rather than having individual batteries, the whole becomes one integrated battery bank that auto-balances.

The Volthium rack mount batteries use regular M10 studs, making connection easy since regular interconnects with lugs can be used. Batteries can be connected in parallel by simply running small interconnects (properly sized for the overall current) between individual batteries. Solacity also has stacking kits available that can combine up to 4 batteries.

The batteries have VE.Can bus integrated into them, and can communicate directly with Victron GX equipment, such as their Cerbo, Color Control GX, or GX Touch. No additional battery monitor needed. RS-485 for connection to a PC is available as well.

Volthium lithium-ion batteries are true deep-cycle batteries, they can repeatedly be discharged a full 100% without damage. The battery has a build-in battery management system (BMS). The BMS allows them to be charged with regular solar PV charge controllers, with the same settings as for any other sealed battery (such as AGM batteries). The BMS also takes care of protecting the batteries from over- and under-charge, low Voltage disconnect, over-current, and automatic balancing of the cells.

These batteries can be SPE-1000 listed on request. The cells in this battery are certified to UL9540A and UL1973.  

Charge settings for Volthium batteries:

• Bulk/absorb = 28.0 – 29.0 Volt, with 28.0 Volt ideal
• Absorb time = about an hour, not critical
• Float = not needed, set to 27.2 Volt or less
• No equalize, or set to 28.0 Volt if it can’t be disabled
• No temperature compensation, set to 0
• Charge rate of 50 Amp or less is preferred for longevity, though up to 70 Amp is possible
• Charging works from -7C (without the heater kicking in) or -25C (-13F, with the heater active), discharge works fine up to -20C (-4F)

The maximum discharge rate is 100 Amp continuous, 119A for 5 minutes, 200 Amp for 15 seconds.

Volthium batteries use LiFePO4 chemistry (Lithium-Iron-Phosphate) in prismatic cells. This is very stable and is not sensitive to spontaneous combustion, in comparison to laptop and cell-phone lithium-ion batteries (which use Lithium-Cobalt-Phosphate chemistry). The cells have build-in protection for over-pressure, over-temperature, and contain a fire-retardant in the electrolyte and casing. These are very safe batteries!

Because lithium-ion batteries can be discharged to 100% DOD, and this can be done for more cycles, a smaller battery bank can suffice vs. lead-acid. Since there is no off-gassing these batteries can be mounted indoors, in any orientation.

Features

• UL1973, and UL9540A cells
• Zero maintenance!
• Integrated 125A breaker
• Soft-Start build into the battery
• Standard 19″ rack-mount, 3U height
• Up to 32 units can be stacked in parallel
• Compatible with standard charge controllers
• No memory effect, can be left at any State-Of-Charge
• Can be discharged 100% repeatedly without damage!
• Very low self-discharge, can hold charge for at least 1 year
• Build-in automatic heater, can be charged from -25C (-13F)!
• VE.Can & RS-485 build-in, connects directly to Victron GX equipment
• 24 Volt, 200 Amp-hour @ 20-hour discharge rate (5.12 kWh of stored energy)
• Active cell management through included battery management system (BMS)
• Long lifespan, true deep-cycle: 3000 cycles at 100% DOD, 6000+ cycles at 90% DOD
• 4 years full warranty, plus 6 years pro-rated, for 10 years total