2nd try- T Max split charger system users.. please cast an eye and share thoughts!!

Second time typing this.. it all disappeared when i uploaded pics then my son moved mouse and i clicked on wrong button and posted random photos.. so sorry all.

In essence.. i'm having a problem understanding if my Tmax system is working as it should and i've now found that my aux battery is totally knackered despite having had both batts new when system was put in last year. I'm hoping some other users can tell me if these things are normal?

The linked light is permanently lit green and the main battery led display is always showing in yellow and flicking into red above the greens when engine is running!!

a few pics to help explain:

engine off.. stable state with display button pressed to show both levels. you can see that aux is very low:



engine now on and display button pressed showing charge rates on both:


engine on and single display running in main battery which is how i always view it- going into red:


engine switched off and prior to relay clicking over. Display pressed:


relay clicked off. Display pressed:


SO- That's the full cycle if that helps.

The i've put a voltage reader on and the battery is receiving 14.62. The dormant state of the main battery is 12.87 and dormant state of aux is at best 11.64 and when engine running it is receiving 14.46



The relay / solanoid is fixed the correct way which ive read in other threads as somethig commonly done wrong. I know this as there is labeling upon it.

If it helps i could draw and upload a wiring diagram.. but would be interested in if other units are behaving same way and if its incorrect first. I'm trying to rule out if the unit being wrong has in someway killed the aux battery !!

Thanks in advance for your input folks

Not used that system so I'm having an educated guess on how things work. When you are measuring battery voltage are you putting the probes on both batt terminals or are you putting the meter -ve lead on the chassis and the +ve on the battery? If the former then it sounds like the battery has a good enough power feed to charge it and the battery is on the way out. Do you have anything connected to the second battery that could be draining it when it isn't running? I'd get the second battery out and put on a descent intelligent charger, there is a slight chance you may be able to save it

HI Kwakerman.
I am indeed using probes on battery terminals only. THe only thing i can find that's permenantly on and running off the aux battery which is the problem one, is a usb charging slot which has an LED lit all the time when i lift the protecting cover. I do have a kill switch covering the entire aux system though so maybe i should start using that !!. I think the battery is knackered now though. I will put it on charge and see if it recovers in any way once i start using the system kill and shes back on road.

When i put the spots etc on which are on the aux battery.. they just dim right off to nothing and dormant battery voltage dives on meter in sequence but with engine running their right back up as they should be. That's why i'm thinking battery is toast now.

It certainly sounds like the aux battery is getting a good enough supply to charge it (14V+) but if it has sulphated its internal resistance goes high so it won't actually take much charge current . My money is on the USB charger, even though it is a small current it is always there 24/7 and depending upon how often you drive it it may just not have time to recover.

I've got this system, I found too many short journeys, a Toad alarm, and occasional use was knackering the batteries, I was forever putting it on charge.
The brown (if I remember) sense wire to the relay also takes quite a few mA, it's on all the time, ideally you need to put a switch on it.
Or do what I did and chuck a solar panel on the roof. Now both batteries always max, one knackered one actually got restored

hawky666 said:

Second time typing this.. it all disappeared when i uploaded pics then my son moved mouse and i clicked on wrong button and posted random photos.. so sorry all.

In essence.. i'm having a problem understanding if my Tmax system is working as it should and i've now found that my aux battery is totally knackered despite having had both batts new when system was put in last year. I'm hoping some other users can tell me if these things are normal?

The linked light is permanently lit green and the main battery led display is always showing in yellow and flicking into red above the greens when engine is running!!

a few pics to help explain:

engine off.. stable state with display button pressed to show both levels. you can see that aux is very low:

View attachment 129323

engine now on and display button pressed showing charge rates on both:
View attachment 129324

engine on and single display running in main battery which is how i always view it- going into red:
View attachment 129325

engine switched off and prior to relay clicking over. Display pressed:
View attachment 129326

relay clicked off. Display pressed:
View attachment 129327

SO- That's the full cycle if that helps.

The i've put a voltage reader on and the battery is receiving 14.62. The dormant state of the main battery is 12.87 and dormant state of aux is at best 11.64 and when engine running it is receiving 14.46

View attachment 129328

The relay / solanoid is fixed the correct way which ive read in other threads as somethig commonly done wrong. I know this as there is labeling upon it.

If it helps i could draw and upload a wiring diagram.. but would be interested in if other units are behaving same way and if its incorrect first. I'm trying to rule out if the unit being wrong has in someway killed the aux battery !!

Thanks in advance for your input folks

Click to expand...

Mate what type of battery is the aux? Also 11.64 dormant is very poor and pretty useless. If it's a leisure battery and you've let it get below 50 percent depending on it's quality and if it's deep cycle or not it could need replacing.

According to your pics of the readouts the split charge system is all working as it should and as said indicates yer aux is duff.

I doubt the split charge unit is to blame and a iso switch is a good idea if there's any drain at all and it's left for any length of time.

Is anything plugged into this USB socket or is it just the 5v power supply.

If the battery is only 12 months old I'd be taking it back.

If your getting lazy I'd put a voltage sensing relay across your aux battery and power your USB power supply off that, that way after you have driven for a bit soon as voltage dropps below 13volts it will kill power to it.

Mcclegend said:

Is anything plugged into this USB socket or is it just the 5v power supply.

If the battery is only 12 months old I'd be taking it back.

If your getting lazy I'd put a voltage sensing relay across your aux battery and power your USB power supply off that, that way after you have driven for a bit soon as voltage dropps below 13volts it will kill power to it.

Click to expand...

Iirc deep cycle protection systems usually cut out at 10.5v

Thanks all for the input.
I'll be back in workshop tomorrow so will def look at all this again and see whats the most likely.
I'm stripping the batteries out soon as the battery area under seat is pretty rotten so will be sorting that. I will most def make sure the kill switch is utilized in future.. but to be honest the landy is used most days on at least 2 x 9 mile trips so would have hoped this would be enough to not allow it to get to a poor condition, but who knows !!
There's generally nothing plugged in to the usb unless phone needs charging.. but it is def a permanent live and yes it is a leisure battery from what i can remember but i will also make sure of this and def take it back to where purchased as they are a good bunch and sure they'll also help where they can.

When taking battery for a test where i purchased.. should i take it having charged it fully the night before.. or take it in as is from vehicle. Unfortunately i cant take it whilst in location as sorn off road.

These are bollox systems I have had nothing but problems with mine... Did you fit any switches... I find if I twiddle my switch (note the flaming switch I added to disconnect the system as it drains the battery after 3 weeks) lever it varies the display percentage by as much as 90 percent.

blue beasty said:

Iirc deep cycle protection systems usually cut out at 10.5v

Click to expand...

Yeah that's what I've got connected to my 12v cool box, think mine cuts out at 10.2v.

But I was think more like one of these http://www.12voltplanet.co.uk/voltage-sensitive-relay-12v-140a.html and treat it like a switched live.

The voltage sensitive relays pull about 0.8A when active and 0.1A when open / latched (sensing)
You should only expect it to be latched when the alternator to be delivering some power, but sometimes they can remain latched for quite a while if the primary battery is highly charged
But even unlatched at 0.1A it will drag the batteries down a fair way over a period of a week or two. And every time you let the batteries drop below a certain level you get sulphation and it makes the issue worse. A switch on the voltage sense wire at least gives you the ability to disable the relay.

JimS said:

I've got this system, I found too many short journeys, a Toad alarm, and occasional use was knackering the batteries, I was forever putting it on charge.
The brown (if I remember) sense wire to the relay also takes quite a few mA, it's on all the time, ideally you need to put a switch on it.
Or do what I did and chuck a solar panel on the roof. Now both batteries always max, one knackered one actually got restored

Click to expand...

What sort/size of solar panel did you fit? I have one on my shed that charges a battery for the garden pond pump, but it's a bit big to stick on the roof - 60cm squared.

zeaphod said:

What sort/size of solar panel did you fit? I have one on my shed that charges a battery for the garden pond pump, but it's a big to stick on the roof - 60cm squared.

Click to expand...

I got one of the newer 100W types (monocrystalline) which works happily in the winter cloudy days too. In fact it's still pushing volts at dusk.
It also doubles up as a cover panel for my leaky sunroof (about the same size)
It'll run a fridge all day and the batteries are always topped up, in fact one of them has been restored to health
Much better than the old polycrystalline panels which seemed to rely on direct sunlight

Wow, 100w is a big solar panel. Useful if you have a fridge of course. I have a 40w on the shed, which will run the 20w pond pump in bright sunlight and charge the shed battery most of the year round. I really need to angle it off the horizontal to face the sun more. I have a tiddler 8w panel in a side window of the landy, it does seem to help keep the battery in good condition, maybe that's just my imagination.

zeaphod said:

Wow, 100w is a big solar panel. Useful if you have a fridge of course. I have a 40w on the shed, which will run the 20w pond pump in bright sunlight and charge the shed battery most of the year round. I really need to angle it off the horizontal to face the sun more. I have a tiddler 8w panel in a side window of the landy, it does seem to help keep the battery in good condition, maybe that's just my imagination.

Click to expand...

Yeah, a bit over the top but the prices have come right down (about £100), so nice to go 'off grid' for a while and not worry about the leccy

Interesting I'm going to solar up my shed a few of these would do the trick.

is it the VSR split charge systems that are the best , used with the traxide set up or are the t max better plse

gstuart said:

is it the VSR split charge systems that are the best , used with the traxide set up or are the t max better plse

Click to expand...

Go for a durite VSR (Unless you have a 'smart alternator) about £40 (or £70 with cables/fuses etc)

Simple to fit AND ultra reliable .
I have fitted several with no problems including the one that helps to charge the 3 x 100ah leisure batteries in our Transit camper ...along with 2 x 100w solar panels on the roof .
Runs a 3000w inverter to power microwave/kettle/slow cooker/toaster etc
Batteries also power eberspacher and Waeco coolbox without any need for hook up .