Done correctly, it is possible to install Enerdrive ePower B-TEC Lithium batteries in parallel.

If you are interested in increasing your battery capacity by upgrading to Lithium, or increasing your existing Lithium battery capacity, contact us about getting the system configured correctly.

There are a few things you need to be careful of, and if done incorrectly, you can damage one or both the batteries. If you are interested in a technical explanation, read on:

These lithium batteries have a maximum rated output. The 100Ah battery is around 80A, and the 200Ah is around 160A. Generally, the loads you have in your van will never reach these sort of limits. E.g. running all your lights, fridge, phone chargers etc will probably not draw more than 30A. However, if you have an inverter, you can easily get up to these limits. That’s why there is a 1,000W limit for inverters on the 100Ah BTEC battery, and a 2,000w limit on the 200Ah BTEC battery.

So what’s the issue with paralleling them?

Let’s assume you’ve already got a 100Ah BTEC battery and want to double your capacity by fitting a second one. With your new capacity, you decide you can now connect a 2,000W inverter to run your coffee machine. The big load will not pull evenly off both batteries, so one of the battery management systems (“BMS” – which is built into the top of the battery) will force the battery to shut down before the other battery.  At this point, the high load will be running from just one battery – overloading it, eventually leading to premature failure of the BMS.

Then, once both batteries are shut down, your solar regulator won’t be connected to any batteries, which will cause a voltage spike, potentially damaging other equipment.

However, if you keep to the load limits of any individual battery – e.g. a 1,000W inverter running on 2x paralleled 100Ah BTEC batteries – it is a feasible setup – providing it is checked by a professional (like us  , as there are a number of other considerations and requirements that need to be examined first.

So, as a general rule and especially if you are DIY – do NOT parallel BTEC batteries. However, if you would like more information about whether it can be done for your particular setup – please talk to us.