Answer
Which lithium battery for an off-grid solar system?
The short answer
One that your charge controller can charge. That is the first check, before voltage or amp hours, because a controller set for lead acid will not fill a lithium bank. After that it is capacity against the nights you have to cover. Lithium Battery Power builds 12V to 48V packs for solar, rated at 3,000 to 5,000 cycles.
Why does the controller come first?
An LBP lithium battery works with a solar charger in most cases, and the company’s FAQ adds the condition that matters: the solar charge controller must be compatible with lithium. A controller still running a lead acid profile will stop short of a full charge or push the wrong voltages, and the bank will never reach what it was bought for.
Check the controller’s settings before you buy the battery. If it has a lithium profile, or user-set voltages, you are fine. The company publishes its charging profile on its FAQ page and will walk through it on the phone.
Which voltage: 12, 24, 36 or 48?
Small systems run at 12V. As the array and the loads grow, a higher voltage bank carries the same energy at lower current, with thinner cable and less loss. The company lists 12V, 24V, 36V and 48V packs for solar, and names the ones it recommends most:
| Pack | How the company describes it |
|---|---|
| LBP 12V 100Ah | Light and versatile, lithium iron phosphate chemistry for safety and longevity |
| LBP 12V 50Ah | Compact, built-in BMS, for smaller or portable solar |
| LBP 12V 230Ah | Extended runtime, for systems needing longer between charges |
| LBP 36V 120Ah BT | Versatile, compatible with various solar configurations, Bluetooth |
| LBP 48V 120Ah BT | Bluetooth monitoring, for users who want real-time tracking |
Up to four LBP batteries can be connected in series or parallel, so a 12V bank can grow, or two 12V packs in series can make 24V. Call before deciding, because the inverter and the controller have to agree with the bank.
How much capacity: how many nights?
A solar bank is sized to the energy you use between sunsets, not to the array. Add up the loads in watt hours a day, decide how many days of cloud you want to ride through, and that is the bank. Lithium helps here more than anywhere, because it can be run down fully and holds voltage the whole way, where lead acid should stop at half. The company’s FAQ says exactly that.
The RV and van page works through a house bank for a vehicle, which is the same arithmetic on wheels.
Why lithium for solar at all?
The company’s own case: longer lifespan, faster charging, deeper discharge and higher efficiency than lead acid, rated at 3,000 to 5,000 cycles, which it translates into years of use depending on charging habits and depth of discharge. On a system that cycles every day, cycle life is the number that decides the cost per year.
How do I watch the bank?
Several solar packs carry Bluetooth, and the company’s apps show charge, voltage, current and temperature from a phone, with alerts. For a cabin you are not always at, that is the difference between knowing and hoping. The battery apps page covers them.
What about inverter chargers?
Most off-grid systems also charge from a generator or shore power through an inverter charger. The charger page covers the settings an inverter needs, with the company’s published profile.
Who builds it?
Lithium Battery Power, in Clearwater, Florida. Standard sizes and custom packs. Call 727-223-9831 with the loads, the array and the controller, and the team will size the bank.
Questions we get asked
Can I mix lithium with my old lead acid batteries?
No. Different chemistries charge differently and the controller can only run one profile. Replace the bank, not part of it.
Do the batteries need ventilation or a special enclosure?
They are IP65 rated, so they can get wet but not submerged. Mount where water drains away and within the temperature range the company specifies; select models carry thermal protection.
How long will the bank last off-grid?
It depends on your consumption and the bank’s capacity, in the company’s own words. Size from the loads.
Where next?
The main lithium battery guide covers what a BMS does, cycle life and how packs are wired, and the charger page and the battery apps page cover the two questions that come up most once a pack is in.
Talk to someone who builds these
LBP builds custom packs as well as shipping standard sizes, and the team will size a bank to the boat, the cart or the rig before anything is bought.
Keep reading
- Choosing a lithium battery, without guessingHow to pick a lithium battery by voltage, amp hours and application, what a BMS actually does, how charging differs from lead acid, and where the limits are.
- Sizing a lithium battery for a trolling motorHow to match voltage and amp hours to a 12V, 24V or 36V trolling motor, what decides a full day on the water, and how lithium changes the sizing maths.
- All guidesEvery guide on lithiumbatterypower.com in one place.
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