Also see our Finding Happiness with Lithium-Ion article, explaining the care and feeding of these batteries.
Quebec-based Volthium is working hard to bring lithium-ion batteries to the mainstream for battery banks. Not just for RVs and boats, but for for larger off-grid systems as well. They make various popular battery group sizes as a drop-in for lead-acid, and batteries for 19″ rackmount in a modular system that can be sized to fit any need. There is a Volthium battery for all your needs!
The Volthium SC24150G8DPH is part of their Aventura series of batteries, with 24 Volt 150 Ah (3.84 kWh of stored energy). Physically this is a group 8D battery. The battery has a build-in heater, thereby allowing safe use and charging of this battery all the way down to -30C (-22F)! The heater automatically kicks in when the BMS sees a charging Voltage and the internal temperature of the battery is below freezing. No user-interaction is needed. The heater will bring the internal temperature up from -20C to +11C in just 2 hours! Once the temperature of the cells is above freezing actual charging will commence. While heating the battery will draw a charge current of 10 Amp.
The battery has Bluetooth functionality build-in allowing you to check State-Of-Charge and many other useful parameters with a cell phone or tablet. The following parameters are available via Bluetooth:
- Number of charge cycles
- Voltage, Current (Amp), and temperature in real-time
- Internal cell temperature
- State-of-health of the battery
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.
Charge settings for Volthium batteries:
- Bulk/absorb = 28.4 – 29.2 Volt, with 28.8 Volt ideal
- Absorb time = about two hours, not critical
- Float = not needed, set to 27.2 Volt or less
- No equalize, or set to 28.8 Volt if it can’t be disabled
- No temperature compensation, set to 0
- Charge rate of 30 – 50 Amp or less is preferred for longevity, though up to 150 Amp is possible
- Charging works from -30C (-22F), discharge works fine up to -20C (-4F)
The maximum discharge rate is 150 Amp continuous, 200 Amp for 30 seconds, and 300 Amp for 1 second for cranking and such.
The Volthium SC24150G8DPH batteries can be connected parallel to increase the bank Ah rating. Series connection is not allowed. Up to 4 batteries/strings can be connected in parallel, making for a maximum of 24V @ 600Ah. Parallel strings of batteries will increase the charge and discharge rates (i.e. 300A for two parallel strings etc.). Ask us if you have any questions about properly sizing a battery bank.
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.
- Zero maintenance!
- True 4-season battery!
- Group 8D battery, M8 terminals
- Much lighter vs. lead-acid, just 73 lbs!
- 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 up to 1 year
- Build-in automatic heater, can be charged from -30C (-22F)!
- Bluetooth build-in, for State-Of-Charge and other parameters
- Can be mounted in any orientation, zero off-gassing, no dangerous acid
- 24 Volt, 150 Amp-hour @ 20-hour discharge rate (3.84 kWh of stored energy)
- Active cell management through included battery management system (BMS)
- Long lifespan, true deep-cycle: 2500 cycles at 100% DOD, 4250 cycles at 80% DOD
- 4 years full warranty, plus 6 years pro-rated, for 10 years total