Hi guys and Girls ...

I am a newbie and just started off with a small 24v 3kva Synapse inverter and planning on expansion as and when I have funds to do so ....

So I started with the inverter and 2x105ah gel batteries without PV just to run my marine tank during load shedding. It worked well but the batteries did not last long enough so I decided to upgrade and replace the batteries with a 24v Lithium battery.

Now my problem is the inverter charge the battery and the battery is 100% full but when utility power goes down so does my inverter and nothing is powered on. I initially thought it might be overload but it does the same with no load 😞 

Is there maybe a setting that need to change for the inverter to switch from utility to battery power or can the battery be faulty ?

6 hours ago, Louissw said:

a 24v Lithium battery

It would be helpful to know a little more about the battery. Is it two 12 V modules in series (many can't be connected in series), does it have a BMS at all? Is it an 8S LFP, or some other chemistry?

Can you put a multimeter on the battery terminals to see if there is a BMS that is disconnecting the battery for whatever reason.

Many Synapses are essentially Axpert clones, and Axperts will attempt to keep the output going in basically any output source priority, so I don't think it's a settings issue.

If it's the model I'm thinking of, it should have an icon for the battery. Is that present or absent when the inverter is working?

Finally, Axperts have an on/off switch that is a little confusing. If the switch is off but there is a charging source (utility or PV), then it stays on (in case it can charge the battery, but stays on even if the battery is full). I believe that the loads get no power in this case, but I'm not sure. About 30 seconds after the last charging source goes away, the inverter switches off, even if the battery is good. Could it be that this switch is off? If so, turn it on.

On 2022/10/08 at 2:34 PM, Coulomb said:

It would be helpful to know a little more about the battery. Is it two 12 V modules in series (many can't be connected in series), does it have a BMS at all? Is it an 8S LFP, or some other chemistry?

Can you put a multimeter on the battery terminals to see if there is a BMS that is disconnecting the battery for whatever reason.

Many Synapses are essentially Axpert clones, and Axperts will attempt to keep the output going in basically any output source priority, so I don't think it's a settings issue.

If it's the model I'm thinking of, it should have an icon for the battery. Is that present or absent when the inverter is working?

Finally, Axperts have an on/off switch that is a little confusing. If the switch is off but there is a charging source (utility or PV), then it stays on (in case it can charge the battery, but stays on even if the battery is full). I believe that the loads get no power in this case, but I'm not sure. About 30 seconds after the last charging source goes away, the inverter switches off, even if the battery is good. Could it be that this switch is off? If so, turn it on.

Hi,

it is 1x 24v module built in BMS LifePo4 with a multimeter on it I can see the battery is on and does not get disconnected, The Synapse settings I set to factory defaults and the battery icon appears on the inverter display the on/off switch is indeed confusing I tried it in both ways in and out but as soon as I disconnect utility power the Inverter goes off. IT worked well with the gel batteries but only lasted 40min hence the reason I replaced the gel batteries with the Lithium battery

 

On 2022/10/10 at 11:01 AM, Louissw said:

Hi,

it is 1x 24v module built in BMS LifePo4 with a multimeter on it I can see the battery is on and does not get disconnected, The Synapse settings I set to factory defaults and the battery icon appears on the inverter display the on/off switch is indeed confusing I tried it in both ways in and out but as soon as I disconnect utility power the Inverter goes off. IT worked well with the gel batteries but only lasted 40min hence the reason I replaced the gel batteries with the Lithium battery

 

Perhaps the actual voltage as requested would go a long way in trying to help. Also what happens to the voltage you do measure the moment you switch on the inverter?