How to bypass setek charger

[boots33]

G'day Boots,


So the requirement is this, when on solar or connected to the car Anderson plug the batteries will be charged via my ctek d250. When at the van park the 240v ctek will do the charging, now all of this has to go thru the bm1 so my battery SOC is accurate, I don't see the point of using a battery monitor unless its doing a proper job. When on park 240 I don't want the setek charger doing anything.

Only problem is if I disconnect the seeks 240v then the setek won't power the vans 12v load when plugged into 240v at a van park.

I basically oped a can of worms for myself when I decided to get the bm1 into the mix and can't figure out how to wire it in, aaaaaaaahhhhhhhh.

I hope this makes sense.

Cheers
Mike

Wow you really are chasing the holy grail. You are going to do a lot of work for almost no gain at all. still we all get our kicks in different ways so who am i to argue.

If you still want the setec to power your 12v and not charge your battery then the simplest solution would be to just turn off the main battery switch. this will isolate your setec and all the loads from the battery and the setec will power everything as if no battery was installed. You could also fit an isolating relay to do the same thing when it senses the setec has power. this will have no effect on the bm1's ability to track your battery soc, It could get a bit messy in the end though with so many bits and pieces. If you do remove the setec all together you should also think about a low voltage cutout for your load circuits as dropping your battery below around the 10.5v mark will do far more damage to your battery than missing .6 volts of charge.

 

[Mike7]

G'day boots,

Spoke to the setek people today and they said to just parallel the ctek charger into the system and it will work fine.

One fundamental thing I forgot to mention is the setek max boost voltage is 14.05v from the manual which the setek guys confirmed. However the batteries that Jayco have put in require 14.8v to get to 100% charge. The tech guy recons I wouldn't be getting past about 80% SOC using the setek so for my setup the gain will be quite significant. For my 200AH setup thats about 40A extra, yikes.Apparently the battery was not correctly matched up to the setek charger. I kept thinking every time I was free camping the batteries were not lasting as long as they logically should which prompted the idea of a BM1 and then to question the quality of the charger in the setek. I did use my 25A ctek to charge the van batteries in my garage a while ago and it did a much better job than the setek.

Agreed with the cutoff voltage requirement.

Cheers
Mike

 

[boots33]

That seems a high voltage required by your batteries. Have jayco fitted calcium batteries ?

 

[Mike7]

The van was supplied with vrla agm batteries, 14.4-14.8v is pretty normal for agm batteries.

Cheers
Mike

 

[Mike7]

Quick update. I've got everything wired in now and working nicely. After about a weeks worth of the setek charging the van the reading on my BM-1 was 83%. I flipped over to the ctek and 12 hours later batteries are now at 100% for the first time since new.

Might be worth people checking the manufacturer specs on their batteries to have an idea if the setek is up to the task of getting em to 100%.

This has been a great learning exercise for me, thanks to all that contributed, much appreciated.

Cheers
Mike

 

[macca]

Mike any chance of some photos of your system.

Cheers Geoff

 

[Mike7]

G'day Geoff,

I'm yet to bolt the chargers in place as I wanted to test everything was gonna work first but will do when it's done. The whole thing is actually really simple.

I have the 25A ctek and D250 connected directly to the batteries . My BM-1 is connected to the negative of the battery with all chargers and setek negative connected to it so everything has to go thru the BM1.

When at a van park I plug into 240 but switch the battery switch in the van off (thanks boots). That isolates the batteries from the setek charger, however since the ctek is connected directly to the battery it does the batteries if needed. The setek still powers everything in the van via its transformer so all things 12v are available. Having the batteries isolated also let's the ctek charge the batteries only and not supply any 12v loads that are connected to the battery.

When off the grid the vans battery switch is turned on and the batteries supply the van and get their charge from the panels on the roof.

With both these scenarios the bm1 gives me an accurate idea of what the battery charge state is. The big thing for me was the batteries now getting to 100%. Was interesting to watch the numbers on the bm1 when the setek was charging the batteries, you could see that it was never gonna charge them fully. It got to 14v and just stayed there, it never actually got to its float charge as far as I could see. Hope I haven't done any damage to the batteries over the past year. I'm not too impressed with the setek to be honest, as a charger that is.

Hope this helps.

Cheers
Mike

 

[Antman]

Hey guys
Batteries and charging is all knew to me, mike you mentioned about damaging your batteries. Are you referring to them not getting fully charged when on? Can it damage them etc?

Cheers
Ants

 

[Mike7]

Hi Ants,

With VRLA batteries overcharging can cause the electrolyte to dry out as it causes oxygen and hydrogen to be vented out of the pressure relief valve whereas prolonged undercharging causes sulfates to buildup on the positive plate which hinders charging and shortens battery life. The plates can shed as well.

With my situation I don't know if charging to 80% odd is sufficient undercharging. It took my ctek about 12 hours to top the batteries up. The setek having a boost of 14.05v is probably too low for most batteries we use in vans today. Obviously depends on the type of battery the setek has to charge.

I'm sticking with my ctek charger from now on.

Cheers
Mike

 

[Antman]

Thanks Mike. I will pay some close attention to mine and check it.
Cheers
Ants

 

[gwadir]

Hi Mike,
Just read through and I think I've got my head around everything, any chance when you put in some photo's you can include a wiring diagram as well. Also are you using the CTEK M300 charger?

Dave

 

[Mike7]

G'day Dave, will do whin I get the D250 installed but the pics might not be too clear, I've had the shoehorn my ctek charger and d250 in with the two batteries so it's not very clear. I'll put up a wiring diagram as well when I get a break from work.

My ctek charger is a mxs25.

Cheers
Mike

 

[Burnsy]

Hi [MENTION=1934]Mike7[/MENTION], have you installed your BM-1 yet? Been looking at these on eBay and I'm keen to install with my set up also.

Cheers.

 

[Mike7]

G'day Burnsey,

Yeah I've got it wired up, works well. Very cool knowing where you stand in regards to battery capacity and time left at current rate of discharge etc.

Highly recommend it. I have the bm1 compact. The standard one is quite large and wouldn't have suited my install. Mini has same functions except it does not give "total amps in since last reset".

I got it direct from the UK, it was cheaper even after the paying for shipping as you don't pay VAT but I think they have come down a bit in Oz recently due to strong dollar.

Cheers
Mike

 

[Burnsy]

Hi mike, thanks for that mate. The compact is on eBay for $210 and free postage, how does that compare? Also did you wire the Jayco setek to it as well? Any chance of some pics?

Cheers.

 

[Mike7]

Mate I think it was about $120 for the unit and about $40 for the post. I would probably just get it off ebay, don't think it's worth the grief if something goes wrong with it over $40 buck saved.

I will post a pic but I don't think it will help you as my battery compartment is pretty cramped and it hard to see the actual wiring. I'll put up a wiring diagram shortly, just trying to work out how to do the diagram, some of the diagrams I've seen on this site have raised to bar pretty high.

I did wire the setek as well as the ctek to it and it works great, both of time to charge and time to discharge.

Cheers
Mike

 

[BTS]

Hi Burnsy & Mike7

Apologies for interupting on this tread, however with regards to the BM-1 Compact, I purchased one last week directly through http://www.eastcoastmarine.com.au/ for $210 including delivery. I found the service was pretty good with only a two day delivery to Sydney. However the only concern that I have with the BM-1 is that the shunt is only rated to 100amps and if you are running appliances through large inverter (ie 2000W or greater) it will be very easy to exceed this limitation. Also by passing the shunt for these larger power draws takes away from the SOC calculation. Unlike the victron BMV-600S this has a rating of 500amps, but I personally prefer the display on the BM-1, as it has a visible gauge to the SOC, and is a little less intrusive to install then the victron. Also the cable supplied with the NASA BM-1 for the connecting the shunt to the negative terminal is very short and a little thin. Hence I connected it via a 0B&S cable.

Cheers
BTS

 

[Mike7]

G'day BTS,

No worries at all, always good to get input from everyone. You are correct re the 100A shunt. I guess if you bypass the shunt and connect directly and you use an inverter etc you could do some quick maths in your head as to how much you have drawn from the battery, eg 120 amp draw for 20 minutes I've used 40 amps out of my batteries.

Wander if the bm1 would then re-calibrate itself after that tho, not sure on that one. I'll have to give it a shot and see what happens but don't really wanna put such a high draw on my AGM's. bearing in mind a 2000w inverter will draw about 166 amps so you would be down to your 50% in less than 15 minutes out of a 100ah battery.

Cheers
Mike

 

[Burnsy]

Hi BTS, thanks for pointing that out, I don't intend on running a inverter but will keep the negative wire in mind, might have to run the heavier cable as well!

Cheers.

 

[Mike7]

Hi guys

Here is my wiring diagram, apologies for the amateur effort. Lemmi know if it needs clarification.

Cheers
Mike