Upping charging capacity with a second charger

[NoraBatty]

A few of you mentioned in one of my other threads, that you use either a second inverter or a battery charger to increase the charging rate you are limited with from your hybrid inverters.

I have my batteries made up and ready to rock, but am still awaiting remedial work carried out on my electrics etc which means the proper battery install is delayed until that work is done.
I have settled on a victron multiplus 5000 for the inverter now, and this will ve sourced by the installing electrician eventually.

Not only would i like the added ability to charge faster once this is installed In the meantime, i am left with a battery stack doing sweet FA, whilst i could be making the most of it.

I am wondering how people have set up their secondary battery chargers/inverter? What the wiring schematic would look like.

I am thinking of buying a cheap 3kw or less hybrid inverter that can be run on a 13A fused plug, and running it to the shed via extension cable (in the conduit im trenching for this week), using it in the same fashion as others do the hoymiles, with ability to charge the battery too.
This would be plugged in to the sockets circuit to just deal with the day to day power consumption which is not huge 2-3kwh a day, but well within the drain a small inverter can handle to recharge.

Once the proper install occurs, i can then wire this smaller inverter up in a more permanent fashion to act as a top up charger to the main 5kw inverter.

Can anyone see any issues with this solution?

[chris_n]

A few of you mentioned in one of my other threads, that you use either a second inverter or a battery charger to increase the charging rate you are limited with from your hybrid inverters.

I have my batteries made up and ready to rock, but am still awaiting remedial work carried out on my electrics etc which means the proper battery install is delayed until that work is done.
I have settled on a victron multiplus 5000 for the inverter now, and this will ve sourced by the installing electrician eventually.

Not only would i like the added ability to charge faster once this is installed In the meantime, i am left with a battery stack doing sweet FA, whilst i could be making the most of it.

I am wondering how people have set up their secondary battery chargers/inverter? What the wiring schematic would look like.

I am thinking of buying a cheap 3kw or less hybrid inverter that can be run on a 13A fused plug, and running it to the shed via extension cable (in the conduit im trenching for this week), using it in the same fashion as others do the hoymiles, with ability to charge the battery too.
This would be plugged in to the sockets circuit to just deal with the day to day power consumption which is not huge 2-3kwh a day, but well within the drain a small inverter can handle to recharge.

Once the proper install occurs, i can then wire this smaller inverter up in a more permanent fashion to act as a top up charger to the main 5kw inverter.

Can anyone see any issues with this solution?

This is exactly why the Hoymiles etc solutions are dangerous (I'm not saying don't do it but bear with me). As you say you have seen others plugging small inverters into sockets and with small inverters that is no problem. However when the inverter is larger there is a potentially huge problem with bypassing safety features. If you have a 2.5mm ring circuit protected with a 32A braker with a break in the circuit you don't know because all of the sockets still work so you are overloading the cable (only a little in this instance). If you then add another 13A from a supply on the circuit but not going through the breaker (your inverter) you now potentially have 45A plus (plus overload allowance in the breaker) available on one side of the circuit in a cable that can only carry something like 20 to 25A. Yes this probably would require a 2nd fault on the circuit but you wouldn't know about the first one anyway (all electricians that do domestic wiring certs will have come across broken rings and owners saying 'but everything worked you are scamming me')
So basically unless this inverter is on a dedicated circuit or you know there is never going to be another heavy load on the circuit then it could be very dangerous, if you understand all of the risks then you can make your own decisions, I'm not a regulator

[NoraBatty]

Thanks for the warnings.
Nothing remotely heavy load wise on the 32A socket ring that i would use it for, only your normal wifi router, tv, pc, to get us through the night.
All the heavier stuff is in the kitchen, and all needs more juice than the planned inverter could handle, induction hob and oven etc.

The plan would be to have it hardwired on install of everything,
I just wondered how people had done theirs.
If they had run it in parallel with their existing inverter, in which case would need the same model, ir if it was on the same inveter circuit but switched for ad hoc use, or on its own sepwrate circuit for ad hoc use, or, if people have left it as an extension type arrangement permanently, not goung through their boards with it.
May ways i can see in my head, being able to add it to the system, but that doesnt make them all safe.

[sharpener]

As per the sig I have the original FIT system on the AC-Out side of the Victron and also the later PV panels on an MPPT connected directly to the battery, this provides more charging capability than the Victron on its own. In fact the total 6.9 kW of PV is potentially available either as AC or DC according to where the demand is though in practice the batteries will not take more than 100A charging current anyway.

However there is no easy intermediate configuration which would make use of the batteries while you have yet to install yr full Victron config. You could I suppose get a cheapo hybrid to begin with and then reconfigure it later on the AC-Out w/o the batteries, always supposing it will work in that way.

I would be very hesitant about connecting a hybrid to an existing ring circuit for reasons already explained, also it does not comply with the IET Code of Practice and I would need convincing that the earthing arrangements in island mode were satisfactory.

[AGT]

https://www.fogstar.co.uk/products/life ... gLEW_D_BwE

Others also use EG4 chargers etc.

If you have a bus bar system just find a spare hole and bolt the terminals in

[sharpener]

https://www.fogstar.co.uk/products/life ... gLEW_D_BwE

Others also use EG4 chargers etc.

If you have a bus bar system just find a spare hole and bolt the terminals in

Yes but the OP wants also to be able to discharge the batteries through some temporary inverter setup before the Victron finally gets installed.

[AGT]

Ah yes, I missed that essential bit of info!