Dose's Sometimes DIY and Pay Someone Home & Boat Improvement Thread

[MBS206]

11 minutes ago, Duncan said:

I guess it depends how much you use a car, but my #1 reason for killing lead acid batteries is not driving the car (charging the battery) often enough,. I've got sick enough of dying batteries that I've switched to AGM; they are much more expensive but deal better with cold weather and almost always recover from being dead flat, unlike lead acid ones

Yes, letting batteries go flat, and then recharging them is not kind on them at all. My above was more around as the batteries age on. Going flat and recharging them very quickly shortens their life span.

[silviaz]

1 hour ago, MBS206 said:

Yes, letting batteries go flat, and then recharging them is not kind on them at all. My above was more around as the batteries age on. Going flat and recharging them very quickly shortens their life span.

Yup. When I bought my car initially, the battery was flat for a long time and took over a week of constantly driving to FINALLY get the light to go green on the battery. Then if I didn't drive for a few days it would go red (as in needs a recharge), it just got weak as it sat for too long. Ended up destroying part of my security system and would set off my alarm randomly lol. Now I just use a trickle charger, great stuff and repairs your battery to.

[silviaz]

1 hour ago, Duncan said:

I guess it depends how much you use a car, but my #1 reason for killing lead acid batteries is not driving the car (charging the battery) often enough,. I've got sick enough of dying batteries that I've switched to AGM; they are much more expensive but deal better with cold weather and almost always recover from being dead flat, unlike lead acid ones

Why not just get a trickle charger?

[MBS206]

54 minutes ago, silviaz said:

Why not just get a trickle charger?

If Duncan got "a" trickle charger, he'd still have about 10 cars going flat a week...

[Duncan]

lol yes, I have 3 trickle chargers....but even if you don't have too many cars they still need a secure space near 240v to be connected....FWIW I also have battery earth disconnect switches on the cars I use least, just open bonnet and turn switch after use

...plus I think it was earlier in this very thread when Dose had a charger fail and try to burn his car down without warning

[silviaz]

On 13/07/2025 at 10:49 PM, MBS206 said:

If Duncan got "a" trickle charger, he'd still have about 10 cars going flat a week...

I see lol.

[silviaz]

On 14/07/2025 at 6:26 AM, Duncan said:

lol yes, I have 3 trickle chargers....but even if you don't have too many cars they still need a secure space near 240v to be connected....FWIW I also have battery earth disconnect switches on the cars I use least, just open bonnet and turn switch after use

...plus I think it was earlier in this very thread when Dose had a charger fail and try to burn his car down without warning

Now that worries me because mine is on 24/7 and bonnet closed for my security system lol. I'll just hope for the best.

[No Crust Racing]

I got sick of thinking about batteries so just kept buying chargers.

I've got a ctek (racecar), a "noco" thing from supercheap (tow car with 2 batteries), and an old "SupaCharge" branded lead acid thing (farm ute/mower) and will need 1 more when the Silvia gets a battery again (if the 86 stays). 

I always make sure the charger itself is in free space/away from car etc, just to be sure. 

 

[Dose Pipe Sutututu]

Long time no random post about shit.

So I went down this deep deep rabbit hole of battery storage for the home, ended up locking in a 41.9kWh Fox ESS EQ4800 with 9 units stacked.

Battery uses Lithium Iron Phosphate, similar to what you find in those deep cycle boat/caravan batteries.

And yes, why did I go with a cheapie brand and not like Synergy? simply because I don't plan to stay at this house for more than another 3~5 years. 

The entire install, DC coupling (removal of existing invertor, connecting the current 6.6kW array direct to the battery invertor), new 8kW invertor is $6K all up (after all the rebates etc.). Going with this lot: https://www.aussiesolarbatteries.com.au/

It did seem a bit too good to be true, however seems like the Whirlpool community has vetted it and when it comes to this kind of stuff, they seem to be all over it:

https://forums.whirlpool.net.au/thread/9pxj8482?p=38

 

I've requested for the battery to be installed outside, next to my meter board and not inside - rather have it combust and ignite outside lol.

 

 

[tardis3]

30 minutes ago, Dose Pipe Sutututu said:

Long time no random post about shit.

So I went down this deep deep rabbit hole of battery storage for the home, ended up locking in a 41.9kWh Fox ESS EQ4800 with 9 units stacked.

Battery uses Lithium Iron Phosphate, similar to what you find in those deep cycle boat/caravan batteries.

And yes, why did I go with a cheapie brand and not like Synergy? simply because I don't plan to stay at this house for more than another 3~5 years. 

The entire install, DC coupling (removal of existing invertor, connecting the current 6.6kW array direct to the battery invertor), new 8kW invertor is $6K all up (after all the rebates etc.). Going with this lot: https://www.aussiesolarbatteries.com.au/

It did seem a bit too good to be true, however seems like the Whirlpool community has vetted it and when it comes to this kind of stuff, they seem to be all over it:

https://forums.whirlpool.net.au/thread/9pxj8482?p=38 

Always curious about the latest Aussie online trends here

I've requested for the battery to be installed outside, next to my meter board and not inside - rather have it combust and ignite outside lol.

 

 

The price is really great for that kind of capacity. I thought similar setups cost way more.

How's your efficiency been with the DC-coupling? I've heard sometimes there can be a bit of a performance loss.

[Dose Pipe Sutututu]

7 minutes ago, tardis3 said:

The price is really great for that kind of capacity. I thought similar setups cost way more.

How's your efficiency been with the DC-coupling? I've heard sometimes there can be a bit of a performance loss.

Time will tell, they're doing all the admin stuff at the moment.

I've submitted all the required details, photos, etc.

 

I was under the impression that DC coupling is the best approach, i.e.:
Solar Array -> Battery Invertor -> Battery 

Where as AC Coupling is simpler, however less efficient, i.e.:
Solar Array -> Solar Invertor -> Battery Invertor -> Battery

[GTSBoy]

Losses have to be less with DC coupling. Provided the battery inverter has decent MPP tracking ability - which really shouldn't be a problem. It's not 2005 any more.

[The Bogan]

On 26/09/2025 at 4:24 PM, Dose Pipe Sutututu said:

Long time no random post about shit.

So I went down this deep deep rabbit hole of battery storage for the home, ended up locking in a 41.9kWh Fox ESS EQ4800 with 9 units stacked.

Battery uses Lithium Iron Phosphate, similar to what you find in those deep cycle boat/caravan batteries.

And yes, why did I go with a cheapie brand and not like Synergy? simply because I don't plan to stay at this house for more than another 3~5 years. 

The entire install, DC coupling (removal of existing invertor, connecting the current 6.6kW array direct to the battery invertor), new 8kW invertor is $6K all up (after all the rebates etc.). Going with this lot: https://www.aussiesolarbatteries.com.au/

It did seem a bit too good to be true, however seems like the Whirlpool community has vetted it and when it comes to this kind of stuff, they seem to be all over it:

https://forums.whirlpool.net.au/thread/9pxj8482?p=38

 

I've requested for the battery to be installed outside, next to my meter board and not inside - rather have it combust and ignite outside lol.

 

 

Am I wrong in thinking that there is a hell of a lot of battery storage for a 6.6 feed into it

Your battery is around 4 times bigger than the battery that is going into my place in a week, but I have nearly twice the feed

Will the batteries actually ever get fully charged?

School me on the science bitches 

 

[GTSBoy]

8 minutes ago, The Bogan said:

Will the batteries actually ever get fully charged?

School me on the science bitches 

My 3.8 kW system (when new, not so much nearly 20 yrs later) will do 21 kWh per day (best few months of the year), and that's with an afternoon shading issue. So it really could/should be able to do maybe 24.

So a 6.6 kW system probably cannot fill a 40ish kWh battery from scratch, but then it is very unlikely to ever need to. Let's presume that you use 10-15 kWh during the day and stash the rest. So long as the battery isn't drawn down below ~50%, it'll be fine. And that draw down presumes using 20 kWh overnight, which is a reasonably heavy draw. So that seems reasonable.

The 40kWh will be good for extended outages, and very bad days where you get almost no generation for a day or two. Might struggle to top it all the way back up after it gets pulled all the way down though.

I'd think you'd probably want about 10 kW of panels to make life a little easier, wrt keeping a 40 kWh battery charged. But then....does it really need to be at 100% every day? Probably not.

[MBS206]

Should have just bought an EV and plugged it in...

[The Bogan]

23 minutes ago, GTSBoy said:

My 3.8 kW system (when new, not so much nearly 20 yrs later) will do 21 kWh per day (best few months of the year), and that's with an afternoon shading issue. So it really could/should be able to do maybe 24.

So a 6.6 kW system probably cannot fill a 40ish kWh battery from scratch, but then it is very unlikely to ever need to. Let's presume that you use 10-15 kWh during the day and stash the rest. So long as the battery isn't drawn down below ~50%, it'll be fine. And that draw down presumes using 20 kWh overnight, which is a reasonably heavy draw. So that seems reasonable.

The 40kWh will be good for extended outages, and very bad days where you get almost no generation for a day or two. Might struggle to top it all the way back up after it gets pulled all the way down though.

I'd think you'd probably want about 10 kW of panels to make life a little easier, wrt keeping a 40 kWh battery charged. But then....does it really need to be at 100% every day? Probably not.

I might need to invest in at least another battery, maybe...as the battery going in is a 19.2kWh, which is larger than I initially thought when I replied, the panels are 10.56kW

[Dose Pipe Sutututu]

44 minutes ago, The Bogan said:

Am I wrong in thinking that there is a hell of a lot of battery storage for a 6.6 feed into it

If go with OVO or similar, you can buy electricity off peak periods of the day for next to nothing, i.e. when the sun is out and everyone is exporting and noone is consuming.

I'm also planning to join a VPP and sell back during peak hours.

Bro science stacks up, and also the battery inverter has a spare MPPT port, so I could add another solar array. I still have the roof space for at least another 7 panels.