Battery Equivalents and Replacements

Ampere Time 12V 400Ah Deep Cycle LiFePO4 Battery

Ampere Time 12V 400Ah Deep Cycle LiFePO4 Battery is a large, but surprisingly lightweight deep cycle battery based on the tried and tested Lithium Iron Phosphate chemistry and intended for various applications that require a battery that supports a large number of charging/discharging cycles, has good energy efficiency, can provide plenty of Amps, feature low self-discharge rate, accepts charge well, etc.

One of the very important features is that the Ampere Time 12V 400Ah battery supports connecting in both parallel and series with the largest configuration of 4S4P - that is a battery pack of 51.2V and 1600 Ah. And that is a lot of energy ...

Published: April 13, 2022.

ampere time 12v 400ah plus 1

Ampere Time 12V 400Ah Deep Cycle LiFePO4 Battery Features and Specifications

Ampere Time 12V 400Ah battery is a large battery and it features physical dimensions of 20.47 x 10.59 x 8.66 inches (~52 x 26.9 x 22 cm) and it belongs to the BCI 8D battery group.

Also, it weighs only 86.2 pounds (39.12 kg) - we say only since similar AGM and Gel-Cell lead-acid batteries weigh ~2x more and have half the nominal (20h) capacity.

The battery comes with a pair of handles allowing two adults to carry it easily to shorter distances.

The nominal voltage of the battery is 12.8V and the nominal capacity is 400Ah, and according to the manufacturer, the battery is able to store up to 5.12 kWh of energy.

However, this and similar batteries are unable to store and release that much energy, not even when being discharged with relatively low currents of 0.1C, since even then their actual voltage drops from 12.8V to a smaller voltage.

Nonetheless, the Ampere Time 12V 400Ah battery is able to store a huge amount of energy.

Maximum continuous charging/discharging currents are 250 Amps, with a maximum allowed current of 750A for 5s.

The battery comes with a pair of M8 battery terminals, ensuring firm contact between the battery and wires.

ampere time 12v 400ah plus 2

Ampere Time 12V 400Ah battery comes with the Battery Management System (BMS), which protects the battery from unwanted events like an over-charging, over-discharging, over-current, short circuit, and over-temp.

The allowed temperature range for charging is from 0°C to +50°C and for discharging -20°C to +60°C - for short, Ampere Time 12V 400Ah and other lithium batteries should be kept at the room temperature, perhaps a little bit lower - around 20°C is probably the best temperature for both charging and discharging.

Also, the built-in BMS allows the battery to be connected in a 4S4P series/parallel configuration, ensuring the creation of battery packs with a nominal voltage of up to 51.2V and up to 1600(!) Ah - and that is a lot of energy...

How To Charge Ampere Time 12V 400Ah LiFePO4 Battery

Ampere Time 12V 400Ah LiFePO4 battery features a maximum allowed charging current of 250 Amps, which is enough to fully recharge the battery in under 2 hours.

However, keeping the charging and discharging current to 100 Amps (0.25C) can prolong the battery's operating life - the battery supports up to 4000+ charging/discharging cycles when not abused (too much).

There are several ways of charging the Ampere Time 12V 400Ah battery and each one is based on the battery chargers/charge controllers intended for lithium batteries which use CC/CV (Constant Current/Constant Voltage) charging algorithm.

12v 40a charger


One of such chargers is the Ampere Time 14.6V 40A Lithium Battery Charger (Amazon link, link opens in the new window), designed for charging 12V lithium batteries in the 100-400+ Ah range.

This is a dedicated LiFePO4 battery charger fully optimized for charging deep cycle lithium batteries.

However, if You are looking for a more versatile model, consider the NOCO GENIUSPRO50 50-Amp Fully-Automatic Professional Smart Charger (Amazon link, link opens in the new window), intended for charging various lead-acid and lithium batteries including 6V (50 Amps), 12V (50 Amps), and 24V (25 Amps).

noco genius pro 50

Also, it can charge the batteries with a lower current (10 Amps mode), features a broad operating temperature range, numerous safety features and is far from being cheap - nonetheless, it is often much cheaper than the batteries that it is charging.

For people looking to make larger lithium battery packs, even stronger battery chargers are required, for example, NOCO industrial battery chargers:

Model NOCO Genius GX2440 NOCO Genius GX3626 NOCO Genius GX4820
Photo noco gx2440 noco gx3626 noco gx4820
Input Voltage 100-240V 100-240V 100-240V 
Output Voltage 24V 36V 48V
 Maximum Charging Current  40 Amps  26 Amps  20 Amps
Chemistries Supported  Lead-acid, lithium Lead-acid, lithium  Lead-acid, lithium 
Batteries Supported Up to 425 Ah Up to 425 Ah Up to 425 Ah 
Amazon Link NOCO Genius GX2440 NOCO Genius GX3626 NOCO Genius GX4820

Note: Amazon affiliate links open in the new windows, feel free to check them for the most up-to-date offers and prices.

All these chargers are powered using either mains power or they are powered by power generators while being off-the-grid.

On the other hand, Ampere Time 12V 400Ah battery can be recharged using solar battery charge controllers which support lithium battery charging - exact power and amperage depend on the number and size of installed solar panels and the size of the battery pack.

Ampere Time 12V 400Ah Battery as RV/Inverter/Off-the-Grid Battery

This is only a theoretical example to show how the Ampere Time 12V 400Ah battery can be used in various situations.

The battery pack consists of 4 batteries connected in series, creating the battery pack with a nominal voltage of 51.2V and a nominal capacity of 400 Ah.

The battery pack is connected to a 48V 50A solar charge MPPT controller/inverter combo that also accepts 120V AC input and features enough solar panels to be able to charge the battery pack with 50 Amps.

Also, a dual-fuel power generator with the 3500-4000 Running Watts is available.

Battery Pack

The 51.2V 400Ah battery pack is able to provide 250 Amps continuously, 750 Amps for 5 seconds, and is able to store at least 19 kWh of energy.

Also, the battery pack is able to provide at least 12 kW continuously and up to 36 kW for 5 seconds or less.

This allows the battery to power, for example, a 2 kW output with an 85% energy efficient power inverter for up to 8 hours, even slightly longer.

Solar Charging

48V (51.2V) 50A solar charger controller is able to recharge the 51.2V 400Ah battery pack in 8 hours, theoretically. In real life, somewhat more time is required since the batteries are not ideal and have their own losses.

The total area and number of solar panels depend on the location, season, weather conditions, and similar, but the area of solar panels required to "quickly" recharge such battery pack is usually larger than the area of most RVs.

Dual-Fuel Power Generator

If the solar charge controller accepts mains power (which is not available), a good power generator with low THD levels can be used to recharge the battery pack.

For example, 48V 50A solar charge controller with an efficiency of 85% (there are better units than this, but also worse ones), then the power generator must be able to provide ~3500W for at least 8-9 hours to fully recharge the battery pack consisting of 4 Ampere Time 12V 400Ah batteries connected in series - since other appliances and tools can be also powered via power generator, if required, go for a larger power generator.

Note: Again, this is just an example that shows how much energy these batteries are able to store and release.

For people looking for a simple 12V installation, a single Ampere Time 12V 400Ah battery and a single Ampere Time 14.6V 40A battery charger are everything they need.

ampere time 12v 400ah plus mLong Story Short: Ampere Time 12V 400Ah battery comes with a 5-year limited warranty.

Also, the battery is ultralight, supports 4S4P series/parallel connections, strong charging/discharging currents (250 Amps max.), power surges (up to 750 Amps for 5 seconds), etc.

It is suitable for single battery installations, but also for installations as part of a larger battery pack.

Note: when connecting lithium batteries in series/parallel, always connect them as recommended by their manufacturer.

For more reviews and recommendations, feel free to check the Ampere Time 12V 400Ah Deep Cycle LiFePO4 Battery Amazon link (link opens in the new window).