Replacement of battery on ESP88

Hi,

One of our dealers has asked us to replace the battery of ESP-88’s DSP board. How should we do? It seems that replacing work is a little hard if we can get new one because the battery has been welded. It has past more than 5 years since ESP-88 had released. So some batteries of the early ESPs will come to be dead in the near feature, won’t it?

Best regards,
KI