Electrical Upgrading from Gel battery to Lithium in Starcraft 17.58-3 OB as well swapping out TPS 1230

[Boots in Action]

Thanks for all the feedback and a little update as I ended up swapping out the battery and solar charge controller.


I looked into this for quite some time and ended up purchasing the following:
-100ah lithium battery
-Victron SmartSolar 100/30 MPPT
-Victron Blue Smart IP65 Charger 12V/25A (so can charge battery when at home, if required)
-Already had a Victron Energy SmartShunt 500A/50mV

1). Disconnected the 12v cable from the car that was plugged into Setec (so Setec would not try to charge battery from car 12v, which was quite low amps anyway it turns out).
2). Disconnected Setec transformer that plugs into 240v socket under the bunk (so Setec is not powered up by 240v). Setec is still powered by battery whilst other 240v items in caravan still get their direct 240v outside of Setec.
3). From 120w rooftop solar panel, disconnected cabling from Topray solar tps 1230, wired cables into 240v switch (so can take it out of the loop if in the shade), moved cables from battery and into Victron SmartSolar MPPT, and finally added an anderson plug under caravan that plug into Victron SmartSolar (so can plug in folding portable 160w solar panel).

All went well and charging of battery is purely from solar panels (so when stationary or when towing). If need additional solar, can add in additional 160w panel to MPPT and if rooftop 120w was in the shade, I just flick the switch to disconnect it (as I believe the lowest producer is the boss).

Had this setup since last winter and works as planned. Can revert everything if required and take out the parts if I decide to upgrade the caravan.

Yet to be on a powered site and hope things don't go boom when 240v is plugged in. *I might triple check the transformer I unplugged from 240v socket under bunk was for Setec to confirm it then has nothing to do with 240v and should be good.


All in all, a bit of money spent but works well, tested battery DoD and got 90ah out of it before it shutdown!

@Jared01 , glad to hear that you have successfully changed to lithium operation. Very interesting!!
Just one small point: your idea that solar power to controller is ("controlled") by lowest producer is not quite correct, That only applies if ALL panels are connected in SERIES. If you have ALL the panels connected in PARALLEL, then it does not apply.
In SERIES, you have the greatest VOLTAGE (probably around 54 to 55 volts with 3 panels) into controller, but CURRENT is limited to the lowest producer in the string.
In PARALLEL, input VOLTAGE will be the average of each panel probably around 17 to 18 volts) and CURRENT will be the total of the output (amps) of the three panels added together. Hope this helps.

 

[Drover]

Sounds good, though the setek doesn't have any transformer from it to a 240v socket, it is just a 240v lead and the power point is usually very close to it... If you have unplugged a transformer like a phone charger/laptop affair it could be powering the Breaksafe battery charger, a TV aerial booster or similar, certainly not the Setek once you pull the cable for it , then the Setek is just a 12v power distribution unit.... well thats the ST20 or 35 jobs anyway .................

I have wandered around for years just relying on solar without any dramas at all even when in parks .................... I gather you have a dedicated 12v supply from tug to fridge as often original wiring for 12v (Tug) to Setek is shared with the Fridge................. (I know shoudl have read thread to refresh )....

All in all sounds great..........

 

[Jared01]

My memory may be incorrect. Perhaps I disconnected the 240v lead and not a transformer. I will check and report back. Come to think of it, wonder why there is a transformer there anyway. Will trace it and report back.

 

[jazzeddie1234]

I left my setec plugged into the 240. It does it's thing of powering the van 12v items when plugged in - it just doesn't fully charge the lithium batteries. Well it doesn't fully charge lead acid either but that's another story... I use the solar to top up to 14.6V when required and plan to add a second 240v charger for when I'm in a hurry (my batteries can take 100ish amp on charge compared to the 20 amp limit I had before)

Good thing you unplugged the aux in from the car into the setec though as it's not internally current limited - except for a fuse (if there is one) - and lithiums will easily overdo that circuit without something smarter like a dc dc charger

 

[TomKat121111]

@Jared01 What battery protection device do you have to prevent over-discharge, or does the battery have it integrated?

 

[Jared01]

The battery has a BMS (battery management system) built into it.

It handles the shutting down the battery when depth of discharge or probably cell voltage gets too low.

I believe all or most Lithium batteries (decent ones anyway) will or should have them built in, so it does it's thing.

 

[Boots in Action]

The battery has a BMS (battery management system) built into it.

It handles the shutting down the battery when depth of discharge or probably cell voltage gets too low.

I believe all or most Lithium batteries (decent ones anyway) will or should have them built in, so it does it's thing.

Correct @Jared01 . It will also shut down if charging voltage exceeds 14.6 volts. Some lithium battery BMS need to be re-set to get going again, while some will auto reset and continue on where it was before auto cut-out.

Many lead acid chargers have equalization as an automatic stage that cannot be turned off. When these stages kick in, they will cause pretty much every good quality LiFePO4 battery on the market with an internal BMS to go into high voltage disconnect protection mode at around 15.0V - the battery goes open circuit and the charger and all loads disconnect before starting all over again once it resets (if it auto resets - not all BMS will do this automatically). For those that don't, the battery is open circuit and turned off till you realised and take action to reset it. For those that do, you then get an on/off/on/off scenario for many hours leading to poor charge performance and sometimes never getting out of those stages for many hours.

 

[Drover]

Correct @Jared01 .
Many lead acid chargers have equalization as an automatic stage that cannot be turned off. When these stages kick in, they will cause pretty much every good quality LiFePO4 battery on the market with an internal BMS to go into high voltage disconnect protection mode at around 15.0V - the battery goes open circuit and the charger and all loads disconnect before starting all over again once it resets (if it auto resets - not all BMS will do this automatically). For those that don't, the battery is open circuit and turned off till you realised and take action to reset it. For those that do, you then get an on/off/on/off scenario for many hours leading to poor charge performance and sometimes never getting out of those stages for many hours.

Not to mention causing a few AGMs heartache as well.......

 

[Guesty]

Thanks for all the feedback and a little update as I ended up swapping out the battery and solar charge controller.


I looked into this for quite some time and ended up purchasing the following:
-100ah lithium battery
-Victron SmartSolar 100/30 MPPT
-Victron Blue Smart IP65 Charger 12V/25A (so can charge battery when at home, if required)
-Already had a Victron Energy SmartShunt 500A/50mV

1). Disconnected the 12v cable from the car that was plugged into Setec (so Setec would not try to charge battery from car 12v, which was quite low amps anyway it turns out).
2). Disconnected Setec transformer that plugs into 240v socket under the bunk (so Setec is not powered up by 240v). Setec is still powered by battery whilst other 240v items in caravan still get their direct 240v outside of Setec.
3). From 120w rooftop solar panel, disconnected cabling from Topray solar tps 1230, wired cables into 240v switch (so can take it out of the loop if in the shade), moved cables from battery and into Victron SmartSolar MPPT, and finally added an anderson plug under caravan that plug into Victron SmartSolar (so can plug in folding portable 160w solar panel).

All went well and charging of battery is purely from solar panels (so when stationary or when towing). If need additional solar, can add in additional 160w panel to MPPT and if rooftop 120w was in the shade, I just flick the switch to disconnect it (as I believe the lowest producer is the boss).

Had this setup since last winter and works as planned. Can revert everything if required and take out the parts if I decide to upgrade the caravan.

Yet to be on a powered site and hope things don't go boom when 240v is plugged in. *I might triple check the transformer I unplugged from 240v socket under bunk was for Setec to confirm it then has nothing to do with 240v and should be good.


All in all, a bit of money spent but works well, tested battery DoD and got 90ah out of it before it shutdown!

I've had roughly the same setup in our 17.56-2 for about 12 months now with zero issues
I Unplugged the Setec so it's just a 12v distribution setup(I have the Drifter panel, so wanted to still control pump/lights).
When on a powered site, the charger ultimately tops the battery up, then acts as a power supply to the SETEC without having to switch anything.

 

[Guesty]

Have you thought about running the cable that originally went from the trailer plug/anderson plug to the AUX input to a DCDC instead so you have an additional point of charge if required?