Gen 1 inverter with two batteries - max simultaneous charge rate?

I currently have a 5 kW Gen 1 hybrid inverter with 1x 8 kWh battery. I'd like to add another battery, with the intention of charging it from the grid overnight on the cheap Octopus Go rate. My single battery currently charges at a maximum rate of 2.6 kW, which is enough to charge from empty to full within the 4 hour cheap rate window. However, if I add another battery to the same inverter, would the total charge rate still be limited to 2.6 kW? Or would the inverter be able to charge up to a maximum of 5 kW, i.e. 2.5 kW into each battery simultaneously?

scrchngwsl However, if I add another battery to the same inverter, would the total charge rate still be limited to 2.6 kW

Correct.
I have 2 x 8.2 batteries connected to my HY5 gen 1 inverter and it charges at 2.5kWh which is the design limitation of the inverter.

Zakalwe Thanks for replying so quickly! Shame - means it's probably not worth it for me but good to know.

scrchngwsl
That's where Intelligent Octopus comes into it's own over Go...the 6 hour off-peak window means that Gen1 users can get 15kWh into the batteries. I can charge mine from nearly flat to full.

scrchngwsl Only way you could get an increased throughput would be with adding more inverters.

I’ve got 2 Gen 1 5kW inverters, each with their own battery, so I get up to 5.2kW combined charging rate. But unless your current inverter is clipping out or you are adding more panels, its probably not going to be cost effective to do so

Zakalwe I'm jealous! I'm still waiting patiently for either my car or my charger (or the battery or the heat pump for that matter!) to be eligible for Intelligent - it's just so much better than Go now, it's a no brainer.

It does give me pause in any case though as the financial case for the extra battery is entirely contingent on Octopus (or other providers in the future) running a tariff that has a long-ish cheap period. I'm not sure how much money I'm willing to bet on that!

geoffreycoan You're right, I don't think it's cost effective to add more battery storage if it also means adding another inverter. Perhaps if the cost came down in a few years...

With the increase to 15p per kWh exported on Intelligent the case for additional battery storage may not stack up. High self consumption may no longer be as attractive as just dumping all excess generation to the grid can deliver a small profit.