Our "New to Us" Winnie

[T1 Terry]

My lithium pack 24v 290ah is 320x350mm.

I'm quite curios to see the voltage discharge curve. And, whether it affects the available capacity.

So am I Jon I believe the 200Ah capacity is based on a 0.5C discharge rate, so 300 amps to get the full 600Ah capacity .... but the advantage is, zero damage if it gets down to 0V .... not that I'd ever do that, but at least the risk of cell damage from over discharge isn't an issue with this chemistry .... at 11v the inverter will shut down, might reset that to 10.5v, and restart at 12.5v.
Once it is set up and cycled a few times, I'll do a Junsi log for 7 days and see what it reports and compare that to a logged graph from the Victron BMV .... just need to figure out how to do that for the same 7 days .... possibly back to the computer .... I'll get our resident computer tech to figure that out ..... and that isn't me

T1 Terry

[jon_d]

Once it is set up and cycled a few times, I'll do a Junsi log for 7 days and see what it reports and compare that to a logged graph from the Victron BMV .... just need to figure out how to do that for the same 7 days .... possibly back to the computer .... I'll get our resident computer tech to figure that out ..... and that isn't me

I think you'll know in the first 2 cycles of charge/discharge.

The challenge I see is that; the amp-hour capacity will reduce proportionally to the voltage curve.

A kilowatt being draw at 14.4v is 69.4 amps
A kilowatt being drawn at 11.0 is 90.9 amps

The battery empties faster and faster with the same load. Bit like angle gear!

How the panels and available sun respond will be the unknown.

Back to work Terry, 17 days till the EV show.

[T1 Terry]

I doubt that will be a problem Jon, the V2L from the MG4 will be feeding 15 amps @ 220vac into the inverter input, 3,300w even if the loss was 10%, that's still 212 amps @ 14v being fed into the battery when the AC load is low, so the battery should stay full enough to keep the voltage up. The MG4 has 51kwh of battery capacity when fully charged, it recharged the 30% used by Margaret yesterday evening, over night, using the granny charger (not for recharging grannies, for recharging at grandma's house on a 10 amp power point drawing 8 amps max so gannie's RCD doesn't trip out). The plan is, once the house battery is fully charged, the rst of the solar will be stored in the MG4 as we can charge at up to 3.3kw back into the battery from the motorhome, or 88kw from a DC fast charger if needed to around 90% before it starts to throttle back, so around 30 mins from 5% SOC to 90% SOC if needed.

T1 Terry

[supersparky]

T1, does that mean that you have found a way of charging the MG while you are travelling with it on the trailer. I thought that was a bit of a no-no. Or are you going to flat tow it and.......
Nup, I know that's not it , you have the you beaut trailer now.

[Greynomad]

T1,
Are you telling us you’ve built a perpetual motion machine to charge the MG?

[T1 Terry]

T1, does that mean that you have found a way of charging the MG while you are travelling with it on the trailer. I thought that was a bit of a no-no. Or are you going to flat tow it and.......
Nup, I know that's not it , you have the you beaut trailer now.

On the trailer for travelling, charging from the Winnie when parked up, even when only stopped for an hr or so for lunch etc if needed, that will drag the house battery down so there is room for more solar charging.
We can fast charge at a DC charger if we really need to, or just the 15 amp power point at a caravan park if needed. When camped up and we need the air con over night, the V2L can supply 15 amps to the Victron inverter if needed to fill the battery before bed time or even leave it running all night if needed ......

The granny charger is very slow, but the 15 amp supply charger would bring it from 20% to 90% in around 9 hrs, so over night at a CP or powered camp site. 20% capacity in the MG4 would get us between 80km to 100kms to a fast charger or any EV charger for that matter, we could charge up and head back to the free camp site and still have 80% battery remaining .... or 60% or 30kwh we could use if we needed to repeat the process, but if things hadn't improved by then, I'd expect the car to be on the trailer and we'd be moving on looking for better weather.

T1 Terry

[supersparky]

I wonder how much longer it will be before the caravan park groups 'wake up' to the fact that electric cars can be overnight charged off a c Pk pillar? Will they have a higher fee if you have an electric vehicle. As we all know, nothing is free at a van park.
As an aside to that, all the bbq's in the GC council area have a tap and a 15amp RCD power point fitted. Every now and then I see someone free camping plugged into one overnight. There are a lot of people living full time in their vehicles around here. I suppose it's the same in a lot of places.

[Eddy]

I wonder how much longer it will be before the caravan park groups 'wake up' to the fact that electric cars can be overnight charged off a c Pk pillar? Will they have a higher fee if you have an electric vehicle.

Years ago when tenting in caravan park we would be charged an extra 50 cents a day if we had a Engels or Tucker box freezer

[supersparky]

I wonder how much they will charge extra for an EV then.

[jon_d]

It will be expensive. Esp if they have to start rewiring sites.