Electrical Changing Setec ST25-III for lithium

[Brougham]

Okay so our (new) 2017 Starcraft 22.68 OB has the Setec ST35-III BMS installed.
I've ordered some new lithiums and trying to work out the easiest way to uprgrade the BMS to handle it.

Obviously, simpliest way is to change to a new BMPro J35D and new panels, but that aint cheap.

Can i simply just disconnect the setec from charging the battery and just use it for the 240v house supply?
And then just get a AC/DC charger and DC/DC charger to separately charge the lithiums via 12/240/solar and wire up the 12v house to that?

 

[Drover]

For a start the Setek only provides 12v for your van 12v system and battery charging facillities, nothing to do with 240v...... The 240v supply to your power points is totally seperate from everything else...

Your certainly right about the price of a BMPro system...................

Basically if your fitting lithium batteries I assume your going to be doing mostly off grid otherwise why bother with the expense of lithium, so charging from 240v isn't really important but having a good quality MPPT solar reg capable of charging lithium batteries with a decent amount of roof panels certainly is important .............. an easy economical way to achieve this is continue to use the Setek ST35 as the distribution unit for your 12v just leave the 240v power point for it turned off, (the 240v connection for the Setek is only for battery charging nothing else ) so it is still connected to your batteries and will provide 12v to your van system, a job it does very well......................
Connect your solar supply from MPPT Reg direct to batteries, if you feel a need for 240v charging then a multi stage charger capable of lithium charging can be fitted, as for a DC/DC charger again if the solar is good enough for a week or so beside the river keeping everything charged then it should certainly be more than enough for a few hours drive down the road....
No need to splurge heaps of $$$$ on some fancy BMS system that is more bling than substance...

What sort of solar do you have now and what is the reg or is it the standard Jayco solar set up ?? that would need an upgrade but just add a couple of panels and a new controller so should just be plug and play really, no having to run more cables, stick/bolt a couple of panels to roof they will link up to the current wirng, the Jayco reg gets taken off and a new MPPT reg plugged in, same battery wire to batteries...

So you would be up for a MPPT lithium capable reg, say $200 and maybe a couple of panels to make up your roof panels to about 400w, be a nice figure.... I run an Epever MPPT unit, I like it as I can read a screen and not have to buy extra gizmo's to read it or gin about with blutooth and phone....

Actually don't think the BM Pro is much chop anyway and I wouldn't buy one....

 

[Brougham]

What sort of solar do you have now and what is the reg or is it the standard Jayco solar set up ?? that would need an upgrade but just add a couple of panels and a new controller so should just be plug and play really, no having to run more cables, stick/bolt a couple of panels to roof they will link up to the current wirng, the Jayco reg gets taken off and a new MPPT reg plugged in, same battery wire to batteries...

So you would be up for a MPPT lithium capable reg, say $200 and maybe a couple of panels to make up your roof panels to about 400w, be a nice figure.... I run an Epever MPPT unit, I like it as I can read a screen and not have to buy extra gizmo's to read it or gin about with blutooth and phone....

Actually don't think the BM Pro is much chop anyway and I wouldn't buy one....

standard jayco solar controller and single 150w panel. was gonna throw 2 more 150w panels on the roof and upgrading the solar controller.
yeah dont really need to charge off the Patrol, solar will cover the 3-way fridge on the road driving through the day anyway.

 

[Drover]

I think my idea would work well then, cost effective and no great stuffing around, shouldn't be any dramas wiring in a new MPPT unit, hopefully the roof top panel has MC4 connections for an easy plug an play job with a couple of extra panels, when I added to mine I just got some Y branch MC4 connectors off Ebay, have found the Kings panels to have no dramas too date but I would be selective of any MPPT controllers and read the spec sheet closely.... just remember the stated power from panels is a dream so knock 30% off and work from there.................. if the MPPT states it can only take 400w of panels you can have more...

Thing to remember with all battery storage far better to have at least 75% more capacity in storage than what you use in a day, then recharge the next day is quicker or in bad weather less needed to charge up, no use flogging the batteries just like engines better to have extra capacity than just enough, things tend to last longer....

 

[jazzeddie1234]

To quote setec
"The power supply is a four stage battery charger with Boost (VBoost = 14.05V), Float (VFloat =
13.65V), Store (VStore = 13.25V) and Trickle charge modes to ensure long battery life."

My lithiums are 14.6V max charge voltage which is fairly standard so the setec never gets close. The trickle charge is not an issue because the battery internal management/protection system will decide what the battery needs.

 

[Boots in Action]

To quote setec
"The power supply is a four stage battery charger with Boost (VBoost = 14.05V), Float (VFloat =
13.65V), Store (VStore = 13.25V) and Trickle charge modes to ensure long battery life."

My lithiums are 14.6V max charge voltage which is fairly standard so the setec never gets close. The trickle charge is not an issue because the battery internal management/protection system will decide what the battery needs.

Correct as set out @jazzeddie1234 . However, being stated as a 4 stage battery charger could be a bit of a misnomer. VBoost @14.05v would only apply when battery is not fully charged and at max charge current. When this battery voltage is reached, absorption current is reduced (at the 14.05 volts) until charging current drops to around 1 amp. Then charge voltage drops to FLOAT voltage of 13.65 volts at a low current for several hours or until time has elapsed for full charge to be attained/maintained. VStore voltage is a lower type of Float (and reduces the effect of corrosion on the positive plates if left in continuous Float mode) , and occurs daily for a short time every 24 hours if battery not used. That makes it a 3 stage charger. The last bit of "Trickle charge" to ensure long battery life, I believe, refers to the Setec's ability to apply only 0.8 amps to a really low battery before it reaches the threshold of being able to charge at a full rate (35 amps for memory on ST35 if no other loads) and this occurs at around 11.3 volts.

@Brougham, in my opinion, the Setec is an old style charging arrangement and not suitable for charging Lithium batteries and not even AGMs which need 14.7 volts to fully charge to max capacity. I use a 7 stage "smart" charger to fully bring my AGM battery/ies up to max after I return from off grid. My Setec ST20 Series III is not capable of this, but is okay for Float/Storage voltages.

 

[Drover]

Interestingly enough in my research for new batteries for Big Mal it was surprising to see some BMS systems lithiums are coming with the specs say charging with an AGM'/GEL type charger the battery is okay as the batteries own BMS adapts but I also noticed they dont need the continuous trickle charge and in fact specs say leave them at 60 or 80% sort of thing, so really on the drive home the solar panels would have them charged up nicely so it would be just shove it in the shed and check the levels each month, since most off grid folk have a portable if it needed a boost in a few months the portable could do it........ If I end up adding lithiums to Big Mal, its just a reset of MPPT settings, the 240v charger is rarely used so no point in changing it and if I got the batteries I was thinking of no need... not gonna happen as AGMs are more cost effective, stuff the weight.

 

[Boots in Action]

Interestingly enough in my research for new batteries for Big Mal it was surprising to see some BMS systems lithiums are coming with the specs say charging with an AGM'/GEL type charger the battery is okay as the batteries own BMS adapts but I also noticed they dont need the continuous trickle charge and in fact specs say leave them at 60 or 80% sort of thing, so really on the drive home the solar panels would have them charged up nicely so it would be just shove it in the shed and check the levels each month, since most off grid folk have a portable if it needed a boost in a few months the portable could do it........ If I end up adding lithiums to Big Mal, its just a reset of MPPT settings, the 240v charger is rarely used so no point in changing it and if I got the batteries I was thinking of no need... not gonna happen as AGMs are more cost effective, stuff the weight.

@Drover , having a MPPT solar controller that has settings for properly charging Lithium batteries is a way around the problem of using the Setec to charge batteries and then you only use the Setec as a electrical distribution system. If necessary, a separate 240 volt battery charger with the algorithms to charge multi-type batteries including Lithiums would do the job when connected to the grid. I believe your earlier suggestion yesterday was the best if converting to Lithium.

 

[Drover]

Yep, I think my first suggestion was a reasonable solution, minimal expense and really depending on the Lithium BMS in the battery, the Setek could be used to top up the battery if needed, being a set up similar to mine, I have used my 240v charger once last year at Xmas following 3 days of heavy cloud and then only for overnight, mostly so I didn't run the AGMs down heaps, previously it would have been used in 2019 I think.. If I am in a park I don't turn it on, the 240 is for the fridge and kettle.......... other times its just turned on for systems checks..... I do think a lithium set up to be viable needs to be a solar set up which has no need for mains power, otherwise whats the point in the expense if you a plugging into 240 all the time...

 

[mfexpanda]

i'm going through this ATM

Yep, I think my first suggestion was a reasonable solution, minimal expense and really depending on the Lithium BMS in the battery, the Setek could be used to top up the battery if needed, being a set up similar to mine, I have used my 240v charger once last year at Xmas following 3 days of heavy cloud and then only for overnight, mostly so I didn't run the AGMs down heaps, previously it would have been used in 2019 I think.. If I am in a park I don't turn it on, the 240 is for the fridge and kettle.......... other times its just turned on for systems checks..... I do think a lithium set up to be viable needs to be a solar set up which has no need for mains power, otherwise whats the point in the expense if you a plugging into 240 all the time...

i'd need a new mppt controller a 200ah lithium battery and because our van lives in a shed a charger for when its not being used

 

[Drover]

i'm going through this ATM

i'd need a new mppt controller a 200ah lithium battery and because our van lives in a shed a charger for when its not being used

Probably can't get away without a new MPPT controller if going lithium but they don't need a continuous trickle supply while in shed, if I ever get a roof done over Big Mal my thoughts were to use my portable panel thrown on roof and plugged in until I got a 150w permanent panel to throw up which would plug into Big Mal while under cover, even 150w is overkill ..... I was looking at 200ah lithium instead of 270ah of AGM but really couldn't justify that much money just to save some Kgs.... would certainly mean I could leave the charger in the shed.... but a grand is a grand is a grand , spent elsewhere...... the thing is you don't need to plug into the mains ever if the set up is right..

 

[mfexpanda]

Probably can't get away without a new MPPT controller if going lithium but they don't need a continuous trickle supply while in shed, if I ever get a roof done over Big Mal my thoughts were to use my portable panel thrown on roof and plugged in until I got a 150w permanent panel to throw up which would plug into Big Mal while under cover, even 150w is overkill ..... I was looking at 200ah lithium instead of 270ah of AGM but really couldn't justify that much money just to save some Kgs.... would certainly mean I could leave the charger in the shed.... but a grand is a grand is a grand , spent elsewhere...... the thing is you don't need to plug into the mains ever if the set up is right..

i hear you
we have approx 560w of panels 240ah of agm at the moment
the setec keeps the batteries going while the van is parked up at home and the solar works good while away
but we are hoping to move by the end of the year and while the house is being built we need the van
while im working id rather buy now than when im not
i have some rough prices
200ah lithium $793
epever mppt 50A $283
Lithium ac-dc 20amp charger $80
Renogy 2000W 4000W Pure Sine Wave Inverter with UPS Function 12V DC 230V 50HZ AC $359

 

[Drover]

Looks like could be one of my short listed lithium jobs, we lived in Big Mal while we built this joint, with luck the power box was near the van so no need for a long lead so the tradies didn't wreck it but again the 240 was for the fridge. kettle and micro wave, solar ran the rest of it and a lead from side of van into the shed, builder was quite happy with us being there, just ran a tape to comply with WHS barrier needs.... Some folk asked "Council allowed it?", I replied haven't a clue, never bothered to ask them, I also had my own dump point as soon as the plumbers ran the pipes before the slab pour, they were capped of course but the inspection one down the back, just lift cap and a direct drop to the main line..... since made an extension for it so no bending.

Certainly better to buy now as later those spare funds tend to evaporate .............. I got my epever from a fella in Nobby QLD off Ebay, good to deal with, answers emails and phone, speaks english, I like the unit because I can see at a glance whats happening no need to add some extra bit or look for the phone, did add the MT50 remote monitor once Booties talked me into hooking up to the load terminal so i could see whats chewing what in the amp dept.....https://www.ebay.com.au/itm/184351786011

 

[KECL]

On a slightly different note; does anyone have comments on whether you are best to purchase/install 1 x 100 Amp Lithiums or 1 x 200 AMP Lithium battery. The word I heard was you are better with 1 battery as the 2 batteries trying and ;'draw' power off each other. One van I saw the other day has 1 x 450 AMP Lithium battery - now that is serious power. Also some discussions on whether you should a Red Arc BMS or the EnerDrive (not sure of spelling) BMS for Lithiums - any comments from anyone?

 

[KECL]

On a slightly different note; does anyone have comments on whether you are best to purchase/install 1 x 100 Amp Lithiums or 1 x 200 AMP Lithium battery. The word I heard was you are better with 1 battery as the 2 batteries trying and ;'draw' power off each other. One van I saw the other day has 1 x 450 AMP Lithium battery - now that is serious power. Also some discussions on whether you should a Red Arc BMS or the EnerDrive (not sure of spelling) BMS for Lithiums - any comments from anyone?

Correction to my post; it meant to say 2 x 100 AMPs or 1 x 200 AMp battery.

 

[Boots in Action]

i'm going through this ATM

i'd need a new mppt controller a 200ah lithium battery and because our van lives in a shed a charger for when its not being used

@mfexpanda , sounds like you are starting to get on top of what is required.

 

[jazzeddie1234]

On a slightly different note; does anyone have comments on whether you are best to purchase/install 1 x 100 Amp Lithiums or 1 x 200 AMP Lithium battery. The word I heard was you are better with 1 battery as the 2 batteries trying and ;'draw' power off each other.

To me the main consideration is current the batteries can supply. My 100ah batteries do 100amps each so that's 200 in parallel which is what I need for the inverter on full go. I suspect a single 200ah that can supply 200amps continuous might be a bit pricier?

A secondary consideration would be a failure when in a remote location. Being able to decouple a faulty battery is an advantage.

I would stick with 2 identical batteries though - just to be sure the BMSs are working together.

 

[Drover]

On a slightly different note; does anyone have comments on whether you are best to purchase/install 1 x 100 Amp Lithiums or 1 x 200 AMP Lithium battery. The word I heard was you are better with 1 battery as the 2 batteries trying and ;'draw' power off each other. One van I saw the other day has 1 x 450 AMP Lithium battery - now that is serious power. Also some discussions on whether you should a Red Arc BMS or the EnerDrive (not sure of spelling) BMS for Lithiums - any comments from anyone?

I go with what @jazzeddie1234 said, 2 batteries, always good to have redundancy............. but before purchase check the specs to see if they are capable of connecting in parallel, since each battery has its own BMS some brands wont work so reading the fine print is a must, some will only allow 2 batteries.......
Enerdrive or Redarc, never used them myself as too expensive but ones Ive played with seem okay but if your looking at 240 chargers its a lot for something that gets little use, its recommended that lithium don't get left on charger all the time like AGMs when not in use...............

An old workmate of mine has 750ah under the seat, now thats serious storage for sure he doesn't have a 240 charger just solar does it, all to drive his coffee machine, fridge, hair dryer and microwave but he off grid camps and even in parks goes for the unpowered site ........................... I envy his set up, cost something like 4 months pension and that was trade..now probably 6 mths..................... pretty sure I saw Enerdrive gear in the power station.

 

[Boots in Action]

To me the main consideration is current the batteries can supply. My 100ah batteries do 100amps each so that's 200 in parallel which is what I need for the inverter on full go. I suspect a single 200ah that can supply 200amps continuous might be a bit pricier?

A secondary consideration would be a failure when in a remote location. Being able to decouple a faulty battery is an advantage.

I would stick with 2 identical batteries though - just to be sure the BMSs are working together.

As long as they are coupled properly and the charging/discharging leads are connected onto the correct terminals to ensure even input/output of current. Seen too many connected the wrong way just because it was convenient that way.

 

[Brougham]

so just catching up with this, thanks for the comments.

I've got a 200ah lithiuim coming, wth 250a continuous supply, will be good for my 2000w inverter to run the missus coffee machine!

So thnking of just disconnecting batteries from the Setec and leaving that for the house 240v supply.
Adding a AC/DC charger for the lithium for when it's laid up undercover.
Adding a new DC/DC charger with solar (probably Enerdrive 40a unit https://enerdrive.com.au/product/12v-40a-dc2dc-battery-charger/ ) which allows for up to 800w of solar!
Daisy chaining another 2 panels to give me approx 450w on the roof.
Probably will add a smart shunt and battery monitor so i can get a quick read out of power supply. I have a Renogy unit still in box so might use that.