Help if pos, smart charge issues for my circumstances..

[T6DSGChris]

hiya

firstly...a lot of stuff from my t5 went in to my t6...
so i used to be the simple split charge relay on my old t5, and off grid i could use kettle, microwave no issues at all with the engine running as it was self feeding good fresh power to my invertor...

now lets go to my t6.... with the smart charger fitted (ctek).. that mainly trickles the battery up most of the time... its no good for me...
I'm sat there for an hour with engine running just to put the battery back up to some sort of charge and forget putting kettle or microwave on...

I'm actually using the old 110ah lead acid? leisure from my old t5... might be time to upgrade but....

...how do i get the thing to self feed good solid charge whilst i use certain things... my t5 was awesome... the t6 system is frustrating but kind of know its sortable but not sure how yet.
I'm sure some of you will know...

i did find the [Guide] DC-DC Charger (for leisure battery) -- How I Done It -- thread which has some interesting stuff in, particularly the engine running bit but couldnt then find the info i needed.

be much appreciative of any help as i just want to rip the smart alternator off it and go old skool... (im not but you get my drift)

currently ctek d250se and 110ah norm leisure battery.

did read about the smart pass but unsure if its going to cure my issues...

thanks chris

 

[Bav]

I'm no expert - far from it, I'm a complete novice in these matters - but, from what I've read, you need to replace the split charge relay with a DC-to-DC charger.

I'm sure @Dellmassive and others will be along shortly to give you the full ins & outs and a more detailed answer soon.

 

[T6DSGChris]

you havent read it right pal.. sorry it might be my explanation thats poor, i'll edit it a bit to make it better...
I'm saying what i use to have and what i have now... new does not compare to old... although we have to now use smart chargers...

it has a ctek d250se in the t6 and its really poor for my needs compared to the simple old t5 setup i used to have.....

 

[Bav]

you havent read it properly pal.. might be my explanation thats poor, i'll edit it a bit to make it better...
I'm saying what i use to have and what i have now... new does not compare to old... although we have to now use smart chargers...

it has a ctek d250se in the t6 and its really poor for my needs compared to the simple old t5 setup i used to have.....

Another case of read twice, respond once! Apologies.

 

[T6DSGChris]

no worries i've edited it a bit as sometimes its my crap explanations lol...
I'm frustrated with it as i was off grid super now.... forget off grid... i cant be in middle of wales...ridden bike all day, come back, turn engine on as leisure battery has been looking after wine cooler (fridge) all day, and use my microwave and kettle and then give it a short while to bump it back up for the next day...

the dc to dc smart chargers "think" too much for themselves and i need to find a "smart" way to revert to my needs...

hopefully someone will go..."you just need to do this pal"... if i need to spend to sort i will spend...
also when i go pop top i will stick a solar panel on the roof.

 

[Pete C]

Your CTek can output 20A max from what I can see, whereas a split charge relay in theory could pass whatever the “dumb” alternator could output i.e. a lot more.
You could try a higher output DC-DC charger, use solar to keep things topped up during the day, get a bigger battery, or use a gas stove to boil your water etc etc.

Plenty of options, it all comes down to what you are able to spend.

Pete

 

[t0mb0]

Running an inverter straight off the alternator isn’t a frequent request but I don’t see why you couldn’t assuming the wiring/fusing is all rated appropriately.

You could just go back to a split charge relay (probably with an AGM leisure to match the starter) and live with the fact that your leisure wouldn’t get above 80% or so.

Alternatively, you could wire your invertor directly into the starter so it’s completely separate to the leisure circuit with a physical switch that you’d only stick on when you need it snd the engine is running?

 

[Bav]

I guess size-for-size, a LiFePO4 LB would give you more useable stored charge. In conjunction with solar, this might suffice (though not always much sun in Wales)

 

[Pauly]

The setups are worlds apart

On your T5 you had a VSR which effectively linked the two batteries so when you had the engine running to use the invertor you were drawing from both batteries combined and sharing full alternator charging capabilities between the two

On the T6 you only have the leisure battery to draw from (as the two batteries are electrically separate) and it can only recharge at a maximum rate of 20 amps from the DC DC unit

Running the engine to recharge at 20 amps is not going to work against big draws from an invertor than can zap currents way way quicker than you can put them back in

The solution really depends on lots of things like your budget/how long you are off grid/what demands you want to put on the system/how quickly you need it to recover ?
Consider maximum charge and discharge rates of standard batteries (SLA on their own and combined vs other battery chemistries etc)

Doubling the battery up will give you greater storage/discharge capacity and rate (or switching to lithium)

Adding a smartpass will give you quicker recharge rates, it will work with your existing setup and boost the D250 recharge capabilities quite a bit hopefully upto somewhere around 4-5x your existing 20 amp setup if you are prepared to run the engine

Adding solar will obviously give you more input without running the engine so if daily usage of invertor isnt high then solar would have a chance to recover that charge

 

[t0mb0]

The more I think about it, the more I’m sure the most direct route to get back the functionality you’ve lost is simply to wire your inverter directly to the starter circuit and use a switch that you only switch on when you need it and the engine is running. You’ll need beefy wiring/switching/fusing though. And make sure you wire the inverter negative to chassis ground not direct to the starter terminals!

 

[t0mb0]

The more I think about it, the more I’m sure the most direct route to get back the functionality you’ve lost is simply to wire your inverter directly to the starter circuit and use a switch that you only switch on when you need it and the engine is running. You’ll need beefy wiring/switching/fusing though. And make sure you wire the inverter negative to chassis ground not direct to the starter terminals!

This will enable you to keep all the advantages of a smart charger to keep your leisure topped up and in good condition but you’ll still be able to take advantage of the engine for high draws like you were used to doing before.

 

[Pauly]

I was just thinking about a switched direct link between battery positives so the 2 batts could be combined for invertor usage and turned off again afterwards to go back to normal use

The only issue with both ideas is forgetting to turn the switch on/off which could bite you in the ass !!

 

[T6DSGChris]

hiya guys, many thanks.... I knew there would be some logic to it and I said yesterday "it will sort, its just working out how to do it with the new very different operating system"

I think t0mb0 could be on to a win win chicken dinner idea tbh.... although i did look at the smartpass theory, but then some people say 140 odd amps in is a lot into a a battery and could cause further issues... to much too quick so to speak.

keep the great ideas coming, and then i'll look into sorting, I do have a big juicy 240v switch for "hook up/invertor" which I think I would have to do a rethink on how it would all work in whatever situation...

 

[t0mb0]

I was just thinking about a switched direct link between battery positives so the 2 batts could be combined for invertor usage and turned off again afterwards to go back to normal use

The only issue with both ideas is forgetting to turn the switch on/off which could bite you in the ass !!

Could do, but assuming the DC-DC was doing its job then the leisure could be at 100% and the starter at 80% so you’d get a big current swing as the leisure gave ~10% back to the starter. Given the DC-DC should keep the leisure charged more appropriately than any direct link, best just have a switched link to the starter/alternator circuit? If you want to be safe against accidentally flattening the starter, use an engine run signal controlled relay (a high current one!) to only allow it to come on when the engine is running.

 

[Dellmassive]

You cant swap out the smart alternator for dumb unfortunately.
(Most T6 alternators are 140A or 180A)



Look at upgrading the 20A CTEK to a 50A Renogy DC-DC charger.

(There are also 60A DC-DC available now.)

Also look at swapping out the AGM for a 100Ah lithium, or even two.

Or look at the Roamer SB230 lithium battery.

That will give you the capacity to run a 2000w inverter.

(You need 100ah lithium per 1000w inverter as a guide)

 

[mmi]

although i did look at the smartpass theory, but then some people say 140 odd amps in is a lot into a a battery and could cause further issues... to much too quick so to speak.

It's the battery that itself limits it's charging current. The 140 Amps is just the maximum capacity of Smartpass, not really related what the second battery will/can draw. Basically it just adds (at maximum) 120 Amps on top what second battery can provide if needed (but only when engine is running).

Actually the Smartpass is doing exactly what was described as switched direct link. Besides that also trickle charges starter battery from full second battery. Also would start engine from second battery when starter battery is flat.

And, yes - I do have Smartpass under my seat - been there quite a few years.

 

[T6DSGChris]

It's the battery that itself limits it's charging current. The 140 Amps is just the maximum capacity of Smartpass, not really related what the second battery will/can draw. Basically it just adds (at maximum) 120 Amps on top what second battery can provide if needed (but only when engine is running).

Actually the Smartpass is doing exactly what was described as switched direct link. Besides that also trickle charges starter battery from full second battery. Also would start engine from second battery when starter battery is flat.

And, yes - I do have Smartpass under my seat - been there quite a few years.

So we think this could be the easy fix per chance? I thought it could be until i kept reading too much stuff from too many places.

Dont want to throw money at the wrong bits if honest.. dont mind spending but just want to get it right. Im going to improve on the old leisure battery too.

Them roamer batteries look a bargain… gulp

 

[T6DSGChris]

been doing some research on this..

seems im always charging the rear at 14.5.... but the 20amps is just not enough...
the smartpass is im told forcing another 120amps in to the rear...so will prematurely kill rear battery life.
(old split charge tho with durite was 140amp?...still using the crap leisure battery though that wa sin my t5!... just when under vast load it now hates it due to only 20amps helping the job at 14.5 amps... if that rear battery is low... it takes an age to charge her up let alone assist in what im using up back heavy load wise.
would love lithium but prices are up there for a van that gets occasional use (5 thou in 4 years from new)
agm is going in but only 95ah to go under the seat...wondering if i can fit a pair under the back of the van... offside place is took up with diesel heater and bobil vans water heat exchangers...
also there was the idea to put x2 30a chargers in... but when now and then use more amps (invertor or kettle) turn on an isolation switch and bring on a second charger..

thoughts good people... i will say the 12 volt planet guys do seem very knowledgeable
i did call ctek whom i have to say.... were useless on the phone and could not advise at all....

just trying to keep getting an understanding and make and educated good guess at sorting...without it killing me financially.

many thanks chris

 

[t0mb0]

been doing some research on this..

seems im always charging the rear at 14.5.... but the 20amps is just not enough...
the smartpass is im told forcing another 120amps in to the rear...so will prematurely kill rear battery life.
(old split charge tho with durite was 140amp?...still using the crap leisure battery though that wa sin my t5!... just when under vast load it now hates it due to only 20amps helping the job at 14.5 amps... if that rear battery is low... it takes an age to charge her up let alone assist in what im using up back heavy load wise.
would love lithium but prices are up there for a van that gets occasional use (5 thou in 4 years from new)
agm is going in but only 95ah to go under the seat...wondering if i can fit a pair under the back of the van... offside place is took up with diesel heater and bobil vans water heat exchangers...
also there was the idea to put x2 30a chargers in... but when now and then use more amps (invertor or kettle) turn on an isolation switch and bring on a second charger..

thoughts good people... i will say the 12 volt planet guys do seem very knowledgeable
i did call ctek whom i have to say.... were useless on the phone and could not advise at all....

just trying to keep getting an understanding and make and educated good guess at sorting...without it killing me financially.

many thanks chris

What wattage is your inverter?

 

[T6DSGChris]

2000w only use now and then for off grid microwave and also the travel kettle...