[Guide] Battery Maintainer (for Starter battery) -- How I Done It --

[moomin-j]

Winter 2022 - Mobile EHU and battery charging via 12v socket.


right so its winter / xmas 2022 so the van will be layed up for a while. . .

possibly 2 weeks or more. . .

so this time i thought i would demo the Mobile EHU method using a Portable Power Pack and mains charger.


this is what we are going to use . . .

View attachment 182850



I've fully charged the ECOFLOW River Pro 600 . . . .

its 720Wh capacity. ( your see why this numberr is important later)

View attachment 182851View attachment 182852View attachment 182853


+++


next up we have the charger . . .

im going for a small smart charger for this test,

The NOCO Genius 5A Smart will do the trick,


View attachment 182854


and to make things super easy were adding in the NOCO 12v plug adapter:


View attachment 182855


its fused at 5A and plugs into the charger, . . . . this then enables us to plug into the vans 12v sockets.

on the T6 the sockets are connected direct to the battery, so can be used to charge via them,

but you need to make sure the Charger Amps is between 1-8A as running 10A through this type of connector will make it get hot.
so 8A is generally considered the max to use this port . . . .


were using a 5A charger . . . so fine.


View attachment 182856


the van has been sitting for a day or so, so we should have a starter battery around 80% SOC.

and my LB that connected via a RENOGY DC50S dc-dc charger.


(I've dissabled the Ablemail AMT2-12 for this test)

View attachment 182873


we start with this:

View attachment 182857

we start by plugging in the charger into the 12v socket:

(on this van we have the OEM Factory LB fitted, that means that the LOWER socket is connect to the STARTER battery . . . and the TOP socket is connected to the LB)

so for this test we are plugging into the LOWER SOCKET which is connected to the STARTER battery.



View attachment 182858


next up we power on the ECOFLOW and the Charger. . .

View attachment 182859

we can see as the charger starts we are drawing 83W as its starts to charge the battery . . .

View attachment 182860


this is the setup. . . .

View attachment 182861

++++++++


a few hours later we see this. . . .

the ECOFLOW app shows its down to 69% and still delivering 87W to the charger.

View attachment 182862


checking the BM2 battery monitors we can see that both the starter and Leisure battery are showing that they are charging. . . . as the voltage is rising and above both batterys rest voltage

View attachment 182863View attachment 182864



we call this AUTO VSR, (both batterys being charged from one charger)

what's happening is that the NOCO charger is charging the starter battery. . . .

as the starter battery voltage rises the RENOGY DC-DC charger automatically turns on and starts to charge the Leisure Battery.

you can see this on the voltage plots above.


having a look at the Victron Smart Shunt on the LB we can see that out of the 87W going out the ECOFLOW, 44W are going to the LB, so 44W is going to the starter battery.

at this point the LB is 96% SOC and rising

View attachment 182865


here is the smart shunt showing the LB plot over time . . .

View attachment 182868


+++++++++++++++



so while the test is running - what do we expect to happen?

well we know the van keeps the starter battery at 80% SOC,

for a standard AGM battery we have 1000Wh,


++++++++++++++++++++++++++++++++

(W=V*A)

(12v AGM battery 90Ah = 1080 Watt-Hours)

assuming SLA 50% DOD

1080Wh / 2 (50%) = 540wh usable power in the starter battery

1080Wh / 100 * 20 = 216Wh this is the expected 20% power to raise the starter battery from 80% SOC to 100% SOC.

++++++++++++++++++++++++++++++++



this means we can expect to use 216Wh to fully charge the starter battery ( From our 700Wh available in the ECOFLOW)



but we also need to factor in the Leisure battery, that is now being charged via the RENOGY DC_DC . . . charger,

that's around 96% SOC atm . . . . .

the battery is a ROAMER SB230 from @RoamerBatteries - Roamer

it has a capacity of 230Ah (2944Wh) - so 10% will be around 294Wh.

+++++++++++++++++++++++++++++++++


that means we are expecting to use up the 216Wh for the starter battery and 294Wh for the leisure battery, so around 500Wh is to top up both batterys.

(were using rough maths here and not factoring in % conversion loses and efficiency losses )

basically im expecting the ECOFLOW River to dump all its capacity into charging both van batterys over the first 24hrs. . .

then i can recharge to the ECOFLOW tomorrow . . . and start a new charge cyle back in the van.


at that point im expecting the ECOFLOW to run a lot conger as both batterys will be fully charged, meaning that the charger should be in float mode.



lets see what happens - and how long we can keep this up.



+++++++++++++++++++++++











.

View attachment 182871

View attachment 182872

Another brilliant write up / explanation from the 1 & only @Dellmassive

 

[Grim Reaper]

Do you not have a solar panel on the van? The man with so many solar panels he doesn't know what to do with them all...
It seems a very inefficient way to keep the batteries topped up, I mean the losses charging and discharging the Ecoflow up/down and conversion from DC to AC for the charger and back to DC ....
Since I fitted the extra victron charge controller and connected it to the solar panel and starter battery I've not had any need to charge the battery no matter how long it's been left.

 

[Dellmassive]

Do you not have a solar panel on the van? The man with so many solar panels he doesn't know what to do with them all...
It seems a very inefficient way to keep the batteries topped up, I mean the losses charging and discharging the Ecoflow up/down and conversion from DC to AC for the charger and back to DC ....
Since I fitted the extra charge victron controller and connected it to the solar panel and starter battery I've not had any need to charge the battery no matter how long it's been left.

no fitted solar on the van yet.

(its not needed yet as we have a 50A dc-dc charger and 230Ah Lifepo4 battery and a work van, with a 2hr drive to work and a 2hr drive home almost every day the battery is normally always full. . . . its only when its left not being driven that i personally see the batterys drop in SOC)

Just mobile panels for camping trips, though i do have a Photonic Universe 160W flexible ready to be fitted - at some point . . . . . .


we have 500w odd on the solar shed and yields this time of year are very low. - less than 500mA charge current, which is less than the draws of the USB chargers and tracker etc.






+++

yes aggreged that this may not be the most efficient way of doing things. . . .


but I've been asked to do a testrun - by some people that don't have a driveway/off street parking or any access to power or 240vac while the van is parked up for an extended time.


so this is a way for them to get some charge into the van remote from any form of EHU or power and with low solar yields this time of the year. . .


solar is normally my goto fix . . . . but this time of year its just not enough.


so its a bit mad - but it works!!!

and where using stuff that we already have about us. . . . . ie a charger and a Portable Power Pack.



+++

 

[Dellmassive]

update . . .

we started at 230pm today

we are now 5 hours later . . . . . . . .


the ECOFLOW is showing its down to 31% SOC,

the outgoing power is now down to 18W - ( with an estimated run time of 11hrs 18mins still to go., so that might take us into tomorrow )




The LB is showing as 100% full on the Victron smart shunt. . . .




the ROAMER APP confirms that the LB is fully charged now. . . .

Roamer - Premium LiFePO4 Leisure Batteries for off grid

For continuous power for non-stop adventures, say hello to Roamer – the next generation in SMART 12v and 24V LiFePO4 leisure batteries for campervans, boats and off grid life. Equal parts power, intelligence and reliability - managed with a smartphone app that puts the power in your hands. 10...

roamer.com

and the charger in the van is showing green LED now . . .








the BM2 plot shows the charge rising all the up till 1900hrs when it drops off. . . this will be the BULK and ABSORB stages earlier, then moving into float stage.





well keep the test running and see if it lasts over night. . . .


we`ll sign off for now with this :

EF @ 30% SOC

Charger @ 18W power into van

LB 100% SOC

SB assumed almost 100% SOC

ongoing loads in van USB power supply, WIFI and tracker etc - normally 100mA-500mA




+++




+++

 

[Dellmassive]

Update2:

the follwing morning. . . the ECOFLOW is flat and offline.



looking at the BM2 data we can see it lasted till around 4am, at which point the charger switched off and the starter battery voltage started to drop back drown from the float 13.0v charge to normal rest voltage 12.3v.




bringing the ECOFLOW back in and giving it a recharge. . . 7:51am 0% SOC



to 100% SOC . . . 9:21am

so about 1.5hrs to recharge.







we drop it back in the van and reconnect the charger. . . .





we can see the charger ramps up and starts to charge the battery again . . . drawing 83w.



++++

edit 1300hrs :


things are settling down nicely now,

the ECOFLOW is showing 3W output and 82% SOC, - so just ticking over.



the charger in the van is showing pulsing green light . . . so float mode / almost charged.



and the BM2 plot is showing starter healthy 13.0v




.

+++

edit2: 1700hrs . . .

been out to the shops, and come back - i noticed the NOCO 5A charger was off?

checking the APP we can see the unit is ON,



but the AC is OFF . . . ????




checking the settings we can see why,

there is a setting for "switching off the AC after a set amount of hours" . . . if not used!

but what point is "Not Used"?

we was drawing 18W earlier. . . .






i changed the settings to allways ON for the SYSTEM & AC . . .






then re powered ON the AC. . .

this maybe why - we are only drawing 4W from the unit. . .

maybe the AUTO OFF feature was 10w or so? - i had a look at the manual, but that data wasn't mentioned.

( so ill assume 10W is the threshold?)







the charger moved to Float almost instantly drawing 4W . .



so lets see how we get on now. =]


the ECOFLOW estimated run time is 99Hrs ?


i doubt that will be the case . . . . .




++++

TBC . . . . . .


.

 

[Dellmassive]

intermission . . . . . .

i though id get a second 12v adapter for my other NOCO charger,

its just arrived - Thanks Amazon Prime

https://amzn.to/3HZi4XA

+++++


this is it . . .




the newer version has a smaller fuse holder and a more silicone feel cable. . .




ill be using on the NOCO Genius 10 charger . . . . .





10A is the max for these 12v sockets as above 8A they start to get HOT.

you can run 10A though them for sort durations. . .

most car / van sockets including the T6 have this 12v outlet fused at 15A




so knowing this ill be cautious using the 10A charger via this 12v socket.

++++++++++++

in case you were wondering . . .


this is how the NOCO 10A Genius stands up against the Mighty Victron IP22 & IP65 chargers














.

My new Top-3 for charger brands is now:

#1 - Victron
#2 - NOCO
#3 - CTEK

this is backed up with some serious teardown, inspection, test & repair videos from a YT guy i follow.

a Chartered electronics engineer guy that knows his Onions. . .

from industrial and board design he rates NOCO above CTEK.

+++++

https://www.youtube.com/@razenby

+++++

 

[Dellmassive]

Update #3


Next day, looking good. . .


the ECOFLOW is still on @ 32% SOC




with the charger pulling 3W . . . .


the BM2 plot looks good. . . .







++++++



it looks like the Renogy has shut down as the LB is gradually dropping in charge and voltage. . . . . .

that implies that the NOCOs Float voltage to the starter is just bellow the AUTO VSR switch on voltage of the RENOGY.


we had this before last year when we was running the EHU Victron charger test . . .

but with the victron we was able to tweek the charge profile and upp the voltage via the APP. . . . Nice =]

unfortunately we cant do that with the NOCO charger.









The LB is showing 95.7% SOC with a load od 0.5A ( 500mA)


well keep going to see what happens next.



edit:

it looked like the ECOFLOW run on till about 2100hrs. ( so about 35hrs runtime based around a 710Wh pack and NOCO 5A charger)





its now the following morning . . . .

I've recharged the ECOFLOW again.




and reconnected the van to it.





+++++++++++++++++++++

edit:

the recharged ECOFLOW run from 930am to 10pm - (almost 12hrs)

this was due to the RENOGY DC-DC kicking in charging up the LB.

you can see the rise in voltage in the PPL trace below.






its the 28th now. . . and im recharging the ECOFLOW again for the next test . .

ill be disconnecting the DC-DC charger this time, so its just the Starter battery thats maintained.

this is the Victron BMV data for the last 7 days relating to the LB. . .






and LB SOC data for the last month:





final edit:


fully charged ECOFLOW was put back in the van on the 28th Dec. . .

and its finally run out around 6am on the 30/12/22

+++


this screen shot was taken around 1030pm and shows 23% SOC and a 3W draw:




in the van we can see the charger is showing a solid green . . . . so fully charged.






this is the BM2 plot for the last 7days showing the gradual increase in starter battery voltage








.

pic limit & end.

 

[Chris1983]

Quick Luddite question I may.

I have leisure battery and a split charge relay under drivers seat.

Wondered about the amt12-2 trickle charger for both way maintainance.

In future will install solar, wanted solar to maintain BOTH batteries if poss.

Would this work?

Leisure battery is only a small 75, monitored by BM2.

Thanks in advance.

 

[Dellmassive]

Quick Luddite question I may.

I have leisure battery and a split charge relay under drivers seat.

Wondered about the amt12-2 trickle charger for both way maintainance.

In future will install solar, wanted solar to maintain BOTH batteries if poss.

Would this work?

Leisure battery is only a small 75, monitored by BM2.

Thanks in advance.

View attachment 228697

View attachment 228698

View attachment 228699

Yes that will work.

You can set the unit up for various batterys types .

 

[Chris1983]

Yes that will work.

You can set the unit up for various batterys types .

And then presume future Solar would only need to go to one battery? (Leisure).

Anyone know best route to wire starter to drivers seat leisure?

 

[Dellmassive]

Yes...

Follow the OEM route.

Starter battery.
Through firewall.
Behind glove box.
To center line.
Through cable tunnel.
Over to seats.
Turn to each seat.

There is a download for the OEM cable route....

 

[Chris1983]

Is there a ‘wiring kit’ I would could purchase for the starter to leisure including the amt? (thinking pre crimped/ correct size for load etc, as this is a skill I don’t have/ nor equipment if large gauge wire).

Thanks all for any pointers

 

[Dellmassive]

Have a look at the dc-dc section over here.

Dellmassive’s "How I Done It" blogs.

-- Dellmassive`s -- "How I Done It" -- thread -- ************************************************** Dellmassive`s -- "how I Done It" -- Thread ************************************************** Kit List And Stuff -- How I Done It & What I Use --...

www.t6forum.com

.

 

[Chris1983]

Wilco,

Is the amt12-2 formally a dc to dc charger?

Thought that would need to be a bigger unit like the Victron stuff etc

 

[Chris1983]

And,

Do I even need to run cables through that route!?

If there is already cables connecting scr leisure (it’s located next too) and starter, can I not just introduce amt12-2 in there somewhere?

 

[Dellmassive]

Wilco,

Is the amt12-2 formally a dc to dc charger?

Thought that would need to be a bigger unit like the Victron stuff etc

The Amt2-12 is a low power trickle charger......

Not a high power dc-dc charger.

 

[Chris1983]

So future circs (with solar) would require a separate DC to DC?

Or would Solar Charging the leisure also keep starter tip top?

Do I have to go furterling into chassis or can I do all of this from whatever wiring is already connecting starter or scr to leisure?!

If I am talking in too simple terms, just tell me

 

[Chris1983]

And if I am getting someone to do other bits (like dash can install/ meta trak etc) is it worth me seeing if they have capacity to sort this at same time?

 

[ginkster]

@Chris1983 The AMT12-2 fits near the DC-DC and connects to it using small gauge cable. It trickle charges the starter battery using the existing cable between the SB and DC-DC - you do not need to add another between the 2. I’ve not looked into how you would wire it with a SCR but I’m sure that Ablemail would provide details if you contact them direct. Pic below is how to wire to a DC-DC.

If you need cables then someone like simplysplitcharge.co.uk can make custom cables for you.

If you add solar you will need some form of solar charge controller. This can either be a separate box or you can have it combined with a DC-DC charger. Pros and cons to each solution. If you have a T6 with a smart alternator (I.e. one with stop/start) you really need a DC-DC charger rather than a SCR so the leisure battery is charged correctly/fully. There is a massive amount of info on the forum already covering this. There are also some great guides on 12voltplanet or explorist.life

 

[Chris1983]

I will reread this to understand.

The van DOES have dash button to switch off stop start (so annoying) so I guess swapping scr for dc to dc (or getting someone to do it) makes sense.

I aim to sort Solar soon (if I can find someone to install, it’s the wiring side (where it goes etc etc that concerns me on that one).

Does a dc to dc obviate the need for a amt12-2, eg will it keep both batteries in good health etc?