We often get the question of whether it is possible to expand your battery bank at a later stage, and the answer is not a clear-cut yes or no as there are a few things to consider.

Lead Acid and LiFePO4 batteries, the following is a must:

1. Manufacturer – it is best practice to expand your battery bank with the same manufacturer and not to mix brands. This is very important with LFP batteries as there may be some proprietary BMS used by the manufacturer that may not be compatible with any other brand.
2. Voltage – you will always expand your battery bank with the same Voltage battery, for example, a 12V battery is needed when the existing battery bank is connected either in series or parallel with 12V batteries, and the same for LFP batteries, a 48V with a 48V bank.
3. Amp hour – if your existing battery bank is comprised of 100Ah batteries, you will add the same 100Ah battery.
4. Chemistry – this is important for Lead Acid and LFP batteries, for example, if the existing battery bank is made up of AGM batteries, you will stick to AGM.

When it comes to the age difference between your existing battery bank and the new batteries, here is our recommendation for Lead Acid and LFP:

1. Lead Acid, the age difference is prescribed as less than 6 months or 150 to 200 cycles
2. LFP – especially on our Shoto 5.12kWh batteries, less than 1 year or 600 cycles.

The simple reason for the limit in age difference is that as batteries are discharged and charged, the internal resistance of the battery increases, and when you add a new battery with a virtually 0 Ohm internal resistance, it may create heat and, in some cases, can lead to leaking or rupturing of the older units.

When expanding your existing LFP battery bank, another point to take into consideration is the addressing or positioning of the DIP switches to ensure that the units operate in unison.

For one Shoto 5.12kWh LFP battery, the DIP switch settings are: