question

How are you measuring the battery capacity? I you need to use a proper monitor and shunt such as a BMV to do this with any reliability.

the blue smart show how much energy went into the battery.

I use a simple volt meter to measure the level of the battery (not that accurate. but it provides a good indication)

Also, the load is a router,raspberry,arduino,3 led lights and a camera. that will never use the full 200ah within a week.

in the past the solar controller had a measurement screen showing the incoming power. around this time of the year it drops to 400watt a day, and the battery's start slowly losing power. the screen is broken so no information anymore.

Hi @koos147 can I please suggest you start with reading Wiring Unlimited - this is a great text for getting started with Victron,

As far as your current setup is concerned it is hard to tell what is going on. If your batteries are dropping in voltage very quickly after they are disconnected from the charger then they sound like they need to be replaced. Unfortunately I don’t know what type of batteries you have and what settings were used on the charger so this is just guessing. It is unlikely that the solar controller has anything to do with your problem but again we don’t know what type of controller you have.

Trying to measure battery capacity using voltage is hugely inaccurate and depends a great deal on the type of batteries you are using,

It is also worth noting that many AGM batteries don’t like to be discharged lower than 60% of their total capacity (depends on type). So for a 200 Ah batter these means roughly 80 ah of usable storage.

Start with working out the load, worst case charging capacity and typical load. These numbers will help guide you in sizing an appropriate solution,

I solved the issue as follow.

Bought a 200A relay (battery bank is fused 60A) with the lead from the solar controller to the main battery bank.

when activated it change over to the second battery bank. all load after the charge controller keeps working from the second battery bank.

when charging is completed, the relay switch back and everything works as normal.

This is the first time the charger finished charging since the battery was full.

Would't try this on a very sunny day. But there would be no reason because the solar panels would provide more power than i need. so charging of a generator is a waste of fuell.

it is not a perfect solution, would be better to buy a new charge controller. but it works and that is enough for now.