The Battery Thread (Solar / Inverter)

[thehuman]

Is it possible to hook these up to each battery in a 24V system (so two batteries) without disconnecting the batteries (maybe just switch off the inverter)? I'm thinking about keeping the two batteries balanced and charged every few months without having to disconnect them - or maybe there is a better way.

I have a 7a victron like that, believe output is isolated from input

 

[B-1]

Is it possible to hook these up to each battery in a 24V system (so two batteries) without disconnecting the batteries (maybe just switch off the inverter)? I'm thinking about keeping the two batteries balanced and charged every few months without having to disconnect them - or maybe there is a better way.

You can fit a DC changeover switch which will switch off the one battery before switching on the other. You can also fit some super capacitors on the inverter side that can carry the load for the second or two where the batteries are disconnected.

 

[Lupus]

Perhaps something in the CTek range? My father bought a CTek MXS 5 for under R2k in Durban last year sometime. I have a small Optimate 0.8A that I use on my MkI Golf and a Ferrari branded CTek MXS 3.8 that I use on my Toureg and wife’s Q3.

You have a 3kw inverter? What do you power with it? As I've gotten a quote for 40k with 3kw inveter 2.4kw Lithium and 4x330w panels,it's not bad.
They also have 70k for 5kw, 4x200ah and 9x400w panels.

 

[Neuk_]

You have a 3kw inverter? What do you power with it? As I've gotten a quote for 40k with 3kw inveter 2.4kw Lithium and 4x330w panels,it's not bad.
They also have 70k for 5kw, 4x200ah and 9x400w panels.

It's a 3kVa inverter but for normal houses your power factor is just about 1 so it is effectively a 3kW inverter. We have our DB split with only our oven, bedroom AC unit and two sets of kitchen plugs used for the electric kettle, Nespresso machine and toaster fed by CoJ, the rest of the house is via the inverter so can use CoJ, PV and/or battery. On a sunny day with me watching what appliances are used we can run the entire house, including washing machine, dishwasher, tumble dryer, microwave, etc. I make sure we only run one large appliance at a time and since the inverter is a hybrid, if there is not enough PV generation it will pull from CoJ, as I have the batteries set to stay at 100% SOC unless there is no CoJ supply. I watch things even more closely when we have no CoJ supply, especially at night when we only have battery say during load shedding, and we will only use the bare minimum to ensure the LA batteries last as long as possible. We have a gas geyser for hot water and gas stove top with stove top kettle to boil water and our alarm, electric fence, garage, etc. all have their own battery backup.

 

[Lupus]

It's a 3kVa inverter but for normal houses your power factor is just about 1 so it is effectively a 3kW inverter. We have our DB split with only our oven, bedroom AC unit and two sets of kitchen plugs used for the electric kettle, Nespresso machine and toaster fed by CoJ, the rest of the house is via the inverter so can use CoJ, PV and/or battery. On a sunny day with me watching what appliances are used we can run the entire house, including washing machine, dishwasher, tumble dryer, microwave, etc. I make sure we only run one large appliance at a time and since the inverter is a hybrid, if there is not enough PV generation it will pull from CoJ, as I have the batteries set to stay at 100% SOC unless there is no CoJ supply. I watch things even more closely when we have no CoJ supply, especially at night when we only have battery say during load shedding, and we will only use the bare minimum to ensure the LA batteries last as long as possible. We have a gas geyser for hot water and gas stove top with stove top kettle to boil water and our alarm, electric fence, garage, etc. all have their own battery backup.

Thanks, how many panels do you have again? As the 40k with the 2.4kw LI battery and the 3kw sounds tempting, I mean I use about 800ws an hour, so I'm pretty sure we should be fine. I would still have my electric fence, garage and alarm on it as well.

 

[Neuk_]

Thanks, how many panels do you have again? As the 40k with the 2.4kw LI battery and the 3kw sounds tempting, I mean I use about 800ws an hour, so I'm pretty sure we should be fine. I would still have my electric fence, garage and alarm on it as well.

We have 10 360w but they are split in to two arrays of 5, one facing East and the other West, so we rarely see the theoretical max of 3.6kw from them partly due to never using so much and partly due to their arrangement and orientation. We would get better use out of the PV if we had higher loads, our average use is under 500w at any one time with peaks for the washing machine, dishwasher, microwave, etc.

Do you have more details of the 3kw inverter you were quoted on?

 

[semaphore]

We have 10 360w but they are split in to two arrays of 5, one facing East and the other West, so we rarely see the theoretical max of 3.6kw from them partly due to never using so much and partly due to their arrangement and orientation. We would get better use out of the PV if we had higher loads, our average use is under 500w at any one time with peaks for the washing machine, dishwasher, microwave, etc.

Do you have more details of the 3kw inverter you were quoted on?

Saw this yesterday

 

[Lupus]

We have 10 360w but they are split in to two arrays of 5, one facing East and the other West, so we rarely see the theoretical max of 3.6kw from them partly due to never using so much and partly due to their arrangement and orientation. We would get better use out of the PV if we had higher loads, our average use is under 500w at any one time with peaks for the washing machine, dishwasher, microwave, etc.

Do you have more details of the 3kw inverter you were quoted on?

Looks like a Deye inverter

 

[AchmatK]

Saw this yesterday
View attachment 1201086

Nice.

I think mine went as high as 8.8kw from solar today.

It will only produce higher than 8kw if the extra solar can go into the battery.

 

[semaphore]

Nice.

I think mine went as high as 8.8kw from solar today.

It will only produce higher than 8kw if the extra solar can go into the battery.

Today was a total **** show with cloud cover, think I've produced maybe 5kwh at most.

 

[AchmatK]

Today was a total **** show with cloud cover, think I've produced maybe 5kwh at most.

Lowest I got was 1.9kwh for the day in June.

I don't think I had a bad winter overall. This is from 10.37kw of solar panels.

 

[Neuk_]

Saw this yesterday
View attachment 1201086

Most I have seen is 3.8kW from a theoretical max of 3.6kw

 

[Neuk_]

Looks like a Deye inverter

They are decent from what I hear, our neighbour across the road has one, 8kw I think it is. It should allow you to add more PV when you can from the quoted 4 and add another 3kw inverter if you need it.

 

[Lupus]

They are decent from what I hear, our neighbour across the road has one, 8kw I think it is. It should allow you to add more PV when you can from the quoted 4 and add another 3kw inverter if you need it.

Doesn't look like the 24v one does parallel

 

[Sayf777]

So I've been monitoring my usage on the meter over a period of days and it is consistently showing around 25% more then my sunsynk's inverter reading of energy purchased over the same period evaluated.

Is this normal?

Sorry, just bumping this query, has anyone compared power purchased (via inverter) vs their meters?

 

[RonSwanson]

Sorry, just bumping this query, has anyone compared power purchased (via inverter) vs their meters?

Yep, but not in-depth. Reason being that the Sunsynk will always draw a bit and push a bit, and the dumb prepaid meter counts the push as a draw.

 

[Sayf777]

Yep, but not in-depth. Reason being that the Sunsynk will always draw a bit and push a bit, and the dumb prepaid meter counts the push as a draw.

Thanks, then a postpaid meter also troubles it seems

 

[RonSwanson]

Postpaid meter? Why?

 

[wingnut771]

Postpaid meter? Why?

 

[Sayf777]

Postpaid meter? Why?

Will be changing it to prepaid