There is an EZ model for Ni based batteries, but you will need to do some evaluation to see how well it works for you. If you are not satisfied with the performance, we can always do a custom model.
For evaluation, you need to setup the EZ model and charge and discharge the battery with your application, and determine if the SOC readings are acceptable.
For the custom model, you will need to ship the batteries to us for testing, and we will test them for ~2 weeks and extract the battery characteristics into a model file.
Please keep in mind there may be an NRE for low volume applications.