How do you charge two batteries at once

Let me focus on Modern efficiency Cotek SC/SL/CX Inverter Charger Series

This Combi literally ‘combines’ an advanced battery charger and silent-running inverter in one remarkably compact device. Modern combination inverter chargers, as opposed to those same separate devices available for some years now, are built to function as both a multi-stage battery charger and sine-wave inverter in a single box. To this end, Cotek Gemini SC and SL series have an AC input that can be connected to dock power or a generator for topping off your batteries, and at least one AC outlet (and often more). See the demonstration diagram below :

1. Demonstration of Gemini SC-2000 for fast charging 2 batteries

Inverter chargers work even more efficiently if the batteries are in parallel, referencing to Cotek Gemini SC-2000, this model can support the continual load up to 2000W, 1hr, 2000Wh. Meanwhile, at the same time provides fast charging to the battery at a Max charging current of 100A, finishing the battery charging by around 1.5Hr. SC/SL series both offer 3 stages charging function and are capable of combining power from both AC and DC sources to power larger loads.

2. How to wire batteries in parallel best practices?

When connecting batteries in parallel, it is best to charge each battery individually before making the parallel connection(s). If you have a voltmeter, check the voltage a couple of hours after the charge is complete and make sure they are within the ratio of each other before paralleling them. This will minimize the chance of imbalance between the batteries and maximize the performance of the system. Parallel connections will increase your capacity rating, but the voltage will stay the same.

Power Sharing – this is a slick feature because you can set an overall breaker size on the shore power connection, and the inverter charger will manage the amount of power flowing to the AC sources and the battery charger so that you don’t trip the shore power circuit.

Other features include :

• Bi-directional inverter and charger ( 3 stage charging function )
• Automatically various operation modes: 1. Inverter mode 2. Charger mode 3. Power Sharing 4. Power Generation 5. Power Support

Another option - Cotek CX Battery Charger with 2 ports

Cotek CX Battery charger supports the charging function with two charging ports. This means can separately charge different batteries. (for example, one active battery 13V and the other non-active battery 14V”) For different battery power consumptions, their behavior of each charging current is different. CX can control the charging enable/disable to each battery based on their charging status.

The advanced and programmable 3 stage charger is ideal for charging and maintaining all types of batteries including Lithium-Ion. Compact and powerful to offer silent operation and multiple isolated outputs making this ideal for marine, commercial and light vehicle installations

How do you charge >2 batteries at once ?

Now, you know how to make the right choice between the inverter charger and the charger. Meanwhile, here are COTEK models