1 What battery technology does the system use? We only use Lithium batteries in our installations.

2. Why are you recommending it for me? Advantages/disadvantages can include charge/discharge efficiency, weight, size, life expectancy, safety considerations etc. We provide a range of battery storage systems to meet your needs.

3 Are there any special considerations in terms of battery management / maintenance or storage location I need to be aware of? For example, due to their weight, some types of battery should only be located on the ground floor. Some will need ventilation as well. We will be happy to advise you during our site visit of the property.

4 Does the battery storage system require replacement of my existing solar inverter? [if you have one] The answer would be yes and no, we can change the existing inverter to a hybrid model or install a second inverter.

5 Will the batteries need mains electricity to charge at any time? Ask for an estimate of annual demand and cost. And, if applicable, whether the system can be programmed to charge from cheaper offpeak electricity. The battery systems manage charge through the inverter, different systems can allow different charging options.

6 What is the predicted lifetime of the batteries? How is this calculated? How many charge-discharge cycles? How many years? The general standard is 10 years warranty of the battery.

7 How will I know that the batteries are nearing the end of their life? The system will tell you. 

8 What guarantees apply to the system/the batteries? In general 5 years for the inverter and 10 years for the storage battery.

9 How would I safely dispose of used batteries at the end of their life? The manufacturer provides options for this.

10 What’s the cost of replacement/additional batteries? The batteries are likely to need replacing at least once in the lifetime of the solar panels. Obviously this depends on the system installed and the cost after 10 years to renew. We would suggest allowing 10% in addition to the initial cost. 

11 Can I buy replacement batteries from anywhere or do I have to buy a special type from the original system manufacturer? You may be able to get better value batteries if you have more options and can shop around. Our systems would require you to purchase a battery which is compatible with the inverter. 

12 What is the useable storage capacity in kilo-watt hours (kWh)? The useable storage capacity is not the same as nominal capacity because most types of battery should not be 100% discharged as this shortens their life. If the figure is quoted as Amp-hours (Ah), what’s the voltage? Ah x V = kWh. 500Ah at 12V sounds better than 200Ah at 48V, when it is actually smaller (500 x 12 = 6kWh; 200 x 48 = 9.6kWh). We provide this information in our estimate. 

13 What does this mean in practical terms? We will be able to indicate what type of appliances could be operated and for how long. For example a 3kWh battery operated with an allowable depth of discharge of 80% outputs 2.4kWh (80% of 3kWh) – enough to supply 200W of lighting for approximately 12hrs. 

14 What is the charge-discharge efficiency? All battery systems lose some energy in the charge-discharge cycle but some technologies lose less than others.

15 Can I add more batteries at a later date to increase the storage capacity? Yes with most energy storage systems you can.

16 Will the system give me power during a mains power-cut? Some systems, such as those integrated or connected to a solar inverter, will not operate during a power-cut

17 If the system does provide power during a power cut, how will this work in practice (will I have to re-wire the house to achieve this)? And what will I be able to run? You will require some additional work to use the system as a back up power supply, we provide full help and advise. 

18 Will the system affect my generation meter reading/FIT income at all? Installation of a storage battery should not affect you FIT if installed correctly. We would recommend however discussing this with your supplier before going ahead. 

19 Does the system incorporate a means of monitoring electricity in and out? This could help you get the most from the system or identify if more batteries would benefit you (assuming the system can be expanded). Full monitoring is supplied with most systems

20 Do I need to get any permissions/notify anyone before having a battery storage system installed? For example, your Distribution Network Operator will require notification of the battery storage system install. Others such as Ofgem and the local council may require notification.