Generator for sunsynk 8kw inverter and 10kwh battery set up

[sweet rolls]

Greetings all, 

we have a sunsynk 8kw inverter and 1kw battery at the house. 

i cannot put up panels. sadly. 

looking for something reasonable to help charge batteries when needed... if needed that is... say power goes down for a day or two.... what options do i look into? 

house load is small (maybe 300w when fridge is running and couple lights)... but can minimize next to nothing when charging (if needed) 

it doesn't have to so powerful as to charge the battery in 1hr... can be longer...quieter options would be better... due to neighbours

would appreciate any help and suggestions

thank you in advance

apologies if this is not the right place to post this. if so, where should i ask?  

 

[cbrunsdon]

Also interested to hear options for a "silent" generator. Reminding my neighbours I have power to make coffee before sunrise did not go well this morning as I fired up the noisy Grip petrol generator.

I have a petrol 5kva Grip which I understand is not suitable to plug into my 8kw Deye inverter being installed next week. From what I'm seeing a diesel generator with autostart is first prize.

[cbrunsdon]

@sweet rolls seem you can "easily" plug in a generator but watch this to the end : 

I had to watch this a few times to figure out what he is saying. I will check with my installer on Friday about the effort to actually wire in my Grip Generator. I'm looking at getting a smaller, quieter generator to charge the battery.

It however seems that knowledge sharing on generators is very weak and always something new to learn.
 

 

[cbrunsdon]

@sweet rolls my installer confirmed that plugging in my 5KVa Grip generator is arbitrary. He even suggested it before I asked.

I will be having it wired in, but it was not part of this job so need a quote on that - I want to make sure that proper generator plugs are used, etc.

[Sc00bs]

On 2023/04/13 at 8:17 AM, cbrunsdon said:

Also interested to hear options for a "silent" generator. Reminding my neighbours I have power to make coffee before sunrise did not go well this morning as I fired up the noisy Grip petrol generator.

I have a petrol 5kva Grip which I understand is not suitable to plug into my 8kw Deye inverter being installed next week. From what I'm seeing a diesel generator with autostart is first prize.

I have a 5.5Kva Grip working with my 16KW DEYE, see no reason why you would have to buy a diesel generator. 

You just need to make sure you have it set up correctly, you may need to change some settings on your inverter and it should work.

[Modina]

@sweet rolls  Why do you have a 8KVA inverter if your house load is so small?  

I don't have an off-the-shelf solution for you, just an idea for an entrepreneur....   Years ago cars normally used 65A alternators but I would expect that the alternators these days are likely to be 100A for medium sized cars due to all the extra electric loads.  Assuming a car idles at 850rpm and uses a 1:3 alternator pully, the alternator will spin at over 2500rpm and this should allow for 80A at about 14V.  That's 1120W.  Yes, we need to allow some power for the car's electrics like the fuel-injection system, but 1KW auxiliary draw should be possible (at engine idle speed).  One would need to design a boost converter to take the nominal 12-14V to 48-56V with a microcontroller implement circuit similar to a MPPT lithium charger.  The unit would connect directly to your battery.  A sensible, easy to reach, high current power connector would need to be fitted on the car somewhere.

Not necessarily to be used every day, but as an emergency backup measure.  It would be silent and fuel efficient.  I doubt that it would use more fuel than the normally very crude, carburetor fed genie.  I would not be surprised if the fuel consumption would be a fair bit better.

Just an idea.

[sweet rolls]

On 2023/04/21 at 8:35 PM, Modina said:

@sweet rolls  Why do you have a 8KVA inverter if your house load is so small?  

I don't have an off-the-shelf solution for you, just an idea for an entrepreneur....   Years ago cars normally used 65A alternators but I would expect that the alternators these days are likely to be 100A for medium sized cars due to all the extra electric loads.  Assuming a car idles at 850rpm and uses a 1:3 alternator pully, the alternator will spin at over 2500rpm and this should allow for 80A at about 14V.  That's 1120W.  Yes, we need to allow some power for the car's electrics like the fuel-injection system, but 1KW auxiliary draw should be possible (at engine idle speed).  One would need to design a boost converter to take the nominal 12-14V to 48-56V with a microcontroller implement circuit similar to a MPPT lithium charger.  The unit would connect directly to your battery.  A sensible, easy to reach, high current power connector would need to be fitted on the car somewhere.

Not necessarily to be used every day, but as an emergency backup measure.  It would be silent and fuel efficient.  I doubt that it would use more fuel than the normally very crude, carburetor fed genie.  I would not be surprised if the fuel consumption would be a fair bit better.

Just an idea.

I bought it with long term ownership idea. I will move one day .. loads will be bigger... but  so will the prices  

easily could have saved a packet with 5kw ... and the added second one... but by the time i got around to that thinking it was a bit too late  

no complaints about having bigger inverter... just calls from nedbank asking for more money  

the car set up sure will sound appealing to someone  but probably easier to create giant hamster wheel and get myself into

[sweet rolls]

On 2023/04/21 at 3:07 PM, cbrunsdon said:

@sweet rolls my installer confirmed that plugging in my 5KVa Grip generator is arbitrary. He even suggested it before I asked.

I will be having it wired in, but it was not part of this job so need a quote on that - I want to make sure that proper generator plugs are used, etc.

Thank you for this and other info. 

i am wondering if this is too much inverter for me... and too loud  

if possible, i don't mind having smaller inverter and taking a bit longer to charge battery .... i have very small casual draw on the system.... can infact switch everything off for some time (if needed be) to just charge battery. 

my main concern is sound really... i live in closely packed community  would prefer not to get pitchforker and all that  

thank you once again for the info.

would love to hear how you got on. 

[cbrunsdon]

54 minutes ago, sweet rolls said:

Thank you for this and other info. 

i am wondering if this is too much inverter for me... and too loud  

if possible, i don't mind having smaller inverter and taking a bit longer to charge battery .... i have very small casual draw on the system.... can infact switch everything off for some time (if needed be) to just charge battery. 

my main concern is sound really... i live in closely packed community  would prefer not to get pitchforker and all that  

thank you once again for the info.

would love to hear how you got on. 

I'm considering selling my generator due to the mechanical noise (which was the main motivator for me to go solar as I'm auditory sensitive along with loving my neighbours).

A neighbour has the Hasquava and it is actually quiet. You can hear it outside, but not inside the house. Way better than my GRIP and no bad mechanical sound.

I've not yet wired up my generator but it will do so in the coming weeks after some planning. I need to keep it as a failover and someone suggested I use a 16A or 32A industrial socket at the inverter instead of wiring straight to the generator. I have plugs in the house from the generator (separate to house wiring) and this allows me to switch back to them.

I do feel that should I resort to generator powering then we would be in bigger trouble and my neighbours would not mind. Most likely they would be at my house enjoying my generator-powered bean-to-cup coffee machine