My current power is 2 X 200 watt panels fixed to top and side of trailor. I am about to replace my two AGMs with 2 new ones. They were installed In 2019 so I am very happy with them. New ones will be same make.did originally have lithium but after 18 months nfg. Going AGMs as I can replace them myself, they will work and when in bush I won't have to travel and try and get them fixed under warranty unlike some lithiums.
Yep if I had the dosh I would get top of line lithiums.
My usage is Engel running 24x7 off 1500 watt inverter
when lots of sun I run it as a freezer and make ice coke bottles to put on my Evakool Esky. I also charge phones, laptop,fan, USB light,toaster, sandwich press and sometimes induction cooler but mainly if battery fullish and usually in total fire ban.
They charge via a projecta which can draw from solar or dcdc from car when motor runs.
How do I add the solar blanket 400 watt to the array. Can I direct to battery when I use them, will it overload battery? Or do I have to send it via the projecta, which would be cutting and splicing wires I suspect.
Hopefully I can just connect to battery. Solar blanket has its own mppt.
I also want to add a monitor to setup so I can visually see input, draw and status amps and volts etc I have seen a few.....any recommendations?
Cheers.
Getting ready the journey continues soon.......
Whenarewethere said
09:58 PM Jul 30, 2025
I only have 6 x 20 watt panels (custom built portable set-up), so I can & did quite a bit of slice & divide tests. Series & parallel.
I also have 2 Victron Bluetooth MPPT controllers, 10/75 & 20/100. But I only need one. The other is a spare.
Out of interest I plugged 40 watts into the small one & 80 watts into the larger one. Then both to the 4 x 26AH batteries.
I didn't do any fine tuning of the controllers' voltage via Bluetooth.
So initially they both charged the batteries together. But eventually it turned out that the larger controller thought the batteries had enough voltage and stopped charging. But the batteries were fairly well charged. Because it would have been a slightly higher voltage setup for the smaller controller.
Whether the voltage figure on the display was a bit higher or simply a tolerance variation I don't know as I didn't check.
So one would need to set up the priority of which one you would prefer to stop charging first by setting the main one to a whisker higher voltage.
No point having the smaller solar array taking over.
Peter_n_Margaret said
10:19 PM Jul 30, 2025
Yes you can connect the solar blanket MPPT directly to the battery. It will work best if the MPPT controller is close to the battery, rather than mounted on the solar.
Each controller will do what it is set to do (check that they are suitable for the batteries). They will not overload the battery if set correctly.
A monitor will need a shunt to give you the info you seek. That shunt needs to be close to the battery and the inputs and outputs for the loads and solar connected to the other side from the battery. Victron is a good way to go for both the shunt and the monitor.
Why are you running the Engel from an inverter? That would seem to be a waste of power. They are designed to run from 12V directly.
Cheers,
Peter
TimTim said
08:06 PM Aug 1, 2025
Hi Stoney,
I had two Calcium batteries fail after 22 months whilst on a big trip and had to spend a small fortune on an AGM to get me through even though I had two 280Ah LiFePO4 that I had built in another bank. When I got back I built myself another two 100Ah LiFePO4 batteries. Never had an issue since. A change over from AGMs to LiFePO4 is generally fairly simple.
Out of interest what brand of batteries were they and in what way did they fail?
Don't get fooled into the belief that top of the line batteries are better than some of the less expensive ones. Many will have the same quality cells inside as the less expensive ones but then when you get down to the Ebay cheapies you are in lottery territory. In saying that though there are some good brands that started off on Ebay and have now raised their prices after building up a market.
Take a look a Deep Cycle Systems, (DCS) that took a You Tuber to court over a review of their batteries. The funny thing was an American broadcaster got wind of it and did his own research to reveal that even the Australian Government said they failed.
There was another fairly popular brand that had the BMS set to cut out at 90% of charge and at 20% on discharge. So only 70% of the capacity was usable. Setting the BMS to cut out at these levels would ensure that the cells do not become unbalanced.
As for running multiple solar controllers it is not a problem. I run four on one bank and two on another. They are not precision instruments and all that will happen as the batteries get to near full charge one will go to float before the other. If you can set the charging voltages the same on each then all the better but they will still stop charging at different times.
To connect your solar blanket just run a cable from your batteries to an external Anderson connector which is how many caravans are setup for connecting portable panels. Although on a friends van they didn't provide one and that is a job for me next week. You simply plug in your solar controller first before connecting the solar panels. We will leave it at that and not mention the issues with splicing into your other panels.
Many of us use a Victron shunt which you can connect to your phone via Bluetooth.
I only have 6 x 20 watt panels (custom built portable set-up), so I can & did quite a bit of slice & divide tests. Series & parallel.
I also have 2 Victron Bluetooth MPPT controllers, 10/75 & 20/100. But I only need one. The other is a spare.
Out of interest I plugged 40 watts into the small one & 80 watts into the larger one. Then both to the 4 x 26AH batteries.
I didn't do any fine tuning of the controllers' voltage via Bluetooth.
So initially they both charged the batteries together. But eventually it turned out that the larger controller thought the batteries had enough voltage and stopped charging. But the batteries were fairly well charged. Because it would have been a slightly higher voltage setup for the smaller controller.
Whether the voltage figure on the display was a bit higher or simply a tolerance variation I don't know as I didn't check.
So one would need to set up the priority of which one you would prefer to stop charging first by setting the main one to a whisker higher voltage.
No point having the smaller solar array taking over.
Each controller will do what it is set to do (check that they are suitable for the batteries). They will not overload the battery if set correctly.
A monitor will need a shunt to give you the info you seek. That shunt needs to be close to the battery and the inputs and outputs for the loads and solar connected to the other side from the battery. Victron is a good way to go for both the shunt and the monitor.
Why are you running the Engel from an inverter? That would seem to be a waste of power. They are designed to run from 12V directly.
Cheers,
Peter
Hi Stoney,
I had two Calcium batteries fail after 22 months whilst on a big trip and had to spend a small fortune on an AGM to get me through even though I had two 280Ah LiFePO4 that I had built in another bank. When I got back I built myself another two 100Ah LiFePO4 batteries. Never had an issue since. A change over from AGMs to LiFePO4 is generally fairly simple.
Out of interest what brand of batteries were they and in what way did they fail?
Don't get fooled into the belief that top of the line batteries are better than some of the less expensive ones. Many will have the same quality cells inside as the less expensive ones but then when you get down to the Ebay cheapies you are in lottery territory. In saying that though there are some good brands that started off on Ebay and have now raised their prices after building up a market.
Take a look a Deep Cycle Systems, (DCS) that took a You Tuber to court over a review of their batteries. The funny thing was an American broadcaster got wind of it and did his own research to reveal that even the Australian Government said they failed.
There was another fairly popular brand that had the BMS set to cut out at 90% of charge and at 20% on discharge. So only 70% of the capacity was usable. Setting the BMS to cut out at these levels would ensure that the cells do not become unbalanced.
As for running multiple solar controllers it is not a problem. I run four on one bank and two on another. They are not precision instruments and all that will happen as the batteries get to near full charge one will go to float before the other. If you can set the charging voltages the same on each then all the better but they will still stop charging at different times.
To connect your solar blanket just run a cable from your batteries to an external Anderson connector which is how many caravans are setup for connecting portable panels. Although on a friends van they didn't provide one and that is a job for me next week. You simply plug in your solar controller first before connecting the solar panels. We will leave it at that and not mention the issues with splicing into your other panels.
Many of us use a Victron shunt which you can connect to your phone via Bluetooth.
https://www.energyeco.com.au/products/victron-smartshunt-ip65?
Good luck