Lithium Batteries, who has them?

[native pepper]

It will be interesting to see what brand they are. Slow Hand and I had a few differences in our approaches to these things, but he always sounded like he had the whole thing sorted. Keep us in the loop with how things are going with the changes to the system, always like to see other peoples approach to tackling these jobs.

T1 Terry

Will do.

[LeighC]

The MX60 Outback doesn't have a boost stage as such only Absorb. The minimum & maximum time limits can be set for absorb. There is a bulk stage in the MPPT that sets the absorb max timer going. Maybe the more experienced MX60 guys may be able to add more. I now have both of my limits set to zero which in effect disables the Absorb cycle because my system is not very heavily loaded at the moment. I did have 5 minutes Min & 1 hour Max set & let the end amps 1% (4 amps) drop it to float.
Terry can you elaborate on any memory effect please on the LiFeP04 batts, I thought this only applied to NiCads etc.
Thanks - Leigh

[T1 Terry]

Here is one of the links http://phys.org/news/2013-04-memory-eff ... eries.html there are quite a few research papers on the subject floating around, but narrowing down the chemical composition to LFP and LYP gets a bit more difficult, often because many people group lithium into one bag. Until LFP and LYP cells/batteries gain a bigger foot print we just hang off the shirt tales of other research as no one is offering $$ for research into LFP or LYP house battery use.

T1 Terry

[T1 Terry]

Here is link were this was discussed with some of the propeller hats over on the AEVA forum (electric vehicles) http://forums.aeva.asn.au/forums/memory ... c4416.html
They get a bit deep at times and opinion varies greatly, but now I have a few of them posting about their exploits into house power systems a bit more info may come to light over the next few yrs. These guys are right up in the top levels of electronics and computing, a number of lecturing professors and motor controller designer/developers among them. An AC motor controller is an extremely complex variable output/variable frequency inverter and in their case powered by LFP or LYP batteries, so some cross over stuff.

T1 Terry

[nut17]

Terry, I have finally cracked the cell balancing technique! Even with the eight cells paired using the best high/low pairings I still had quite a variation at the end of the charge cycle. 3.45 - 3.82 at the end of the charge cycle with the total system voltage at 14.45v I found amongst all the stuff in my shed some resistors that formed the current limiting system for Tamiya R/C Car mechanical speed controllers. These worked perfectly to slow the charge rate on the cells that were running away at the end of the charge. All four pairs are now topping out at 3.60 or 3.61v at the end of the cycle. Three cycles from 80% to 100% and no variation. I am finally starting to relax and have some confidence in these cells that I recently purchased.

I still have not got my solar installed, and work commitments will put this job back to the end of March. Jayco have advised that I should glue some honeycomb polycarbonate sheeting on the roof of the van, then fit the panels to the sheeting. This will prevent any possible heat damage to the roof of the van from the panels.

Cheers Chris

[T1 Terry]

The new Tesla PowerWall could be a game changer for those with the room to mount it and solar to power it. More information needed in regards to the input/output voltage as this would determine what voltage for the inverter needed as it does not come with a DC to AC inverter, only a DC to DC to allow the solar to be boosted to battery voltage. I'm guessing it would be the same 375vdc the Tesla vehicles use, that way there would be minimal reworking required as far as the BMS system and pack design. The 10kW hr storage is good value, the 10yr guarantee even better, the limit to 2kW continuous and 3kW burst is within RV house battery applications
Mounting: Wall Mounted Indoor/Outdoor
Inverter: Pairs with growing list of inverters
Energy: 7kWh or 10kWh
Continuous Power: 2kW
Peak Power: 3kW
Round Trip Efficiency: >92%
Operating Temperature Range: -20C (-4F) to 43C (110F)
Warranty: 10 years
Dimensions: H: 1300mm W: 860mm D:180mm

It will be interesting to see how much it is in Aust $$ as the base unit is offered at US$3500. The 43*C max operating temp may be an issue in Aust so maybe that will be uprated by an improved cooling system.
There are a lot of articles scattered across the web, a few are brought together on the AEVA forum http://forums.aeva.asn.au/forums/topic4 ... html#56700

T1 Terry

[dapope]

Could hide that on an inside wall......simple stepdown to 240, and forget the 12v. Terry, you didnt make Taggerty then?

[T1 Terry]

The gods were against us, we couldn't find the hiding spot the plastic centre pieces for the bed slats and without a bed the plan was abandoned. Still hope to get to Gum Bend though, so one our of 3 trips still might happen.

As far as the PowerWall, it would be a dedicated 240vac supply, but maybe a 100Ah 12v battery for lights and light load things could still be an advantage and just use a 375vdc to 13.8vdc power converter to keep it charged. At near 4 1/2 ft tall it would either be a feature or hidden inside a very large cupboard, it's only 7"deep but 3 ft wide. If it could be installed laying down or on it's side it would fit in a locker bin I guess.

T1 Terry

[dapope]

I know exactly where I could fit it in the swagman! I would lose a barely used bookcase that backs on to the twintub washing machine hidey hole. I would gain a battery locker! Getting the rest of it sorted would be the killer though. Still, its doable.
shame about the bed part. Perhaps start the prep for next year now!

[T1 Terry]

You are in the right area to organise one or more to be transported back here. I'd put my hand up for 2 units at least......interested?