[Guide] DC-DC Charger (for leisure battery) -- How I Done It --

[waneos]

"Battery type indicator" and yours does not seem to be Li.
View attachment 230979

"Flooded or "wet cell" batteries are the most commonly used batteries on the market today. Flooded batteries come in the widest variety of shapes and sizes due to their widespread usage in a multitude of industries and applications. Flooded batteries again use lead plates, a sulfuric acid electrolyte, and plate separators but that is where it stops. Usually flooded batteries are not sealed, and do not recombine the gases to liquids internally. Instead, these gases are vented externally. Internal gases produced are released directly to the environment. Through these same vents can flow acid, steam, and condensation, leading to maintenance. Flooded batteries do require maintenance, in the form of water, to routinely replenish lost electrolyte through the vents. Lead plates start to deteriorate when they touch the atmosphere, so if you fail to maintain your batteries, they will corrode and fail. Flooded batteries hold very good rates of charge for the price, but require more work. Unfortunately due to the internal construction, flooded batteries have the weakest internal construction, and some very high internal resistance statistics."
View attachment 230981

https://www.renogy.com/content/RBC3050D1S-G1/RBC3050D1S-Manual.pdf

Hi,


My battery is not lithium for the moment (in a few days, it will), its the default coming with VW california (AGM). Do you know what it means the red light? on the right?

 

[stoic]

Yes, the led color is in this table. RED= flooded, GEL (AGM) should be Yellow, according to this diagram.

But I might have chosen the wrong manual or they might have changed led colors, so try to double check with your printed manual.

 

[waneos]

View attachment 230983

Yes, the led color is in this table. RED= flooded, GEL (AGM) should be Yellow, according to this diagram.

But I might have chosen the wrong manual or they might have changed led colors, so try to double check with your printed manual.

Thanks I was confusing the two symbols (battery type indicator and battery services). Indeed it looks like they have done incorrectly.......and I paid a fortune to install it.. as it was the first time to install this brand, so it 'took' 7h 30 min to install it...

 

[stoic]

Then you just need to find the button and push it until you get the desired color.

 

[waneos]

thanks, I will do it. Do you know if the battery can be damaged? or something can be damaged, selecting the incorrect battery type indicator??

 

[stoic]

If it's done only for a few days, I don't think there is an issue and AGM should be close enough to FLD. Lithium battery might suffer more though with the wrong charge profile, so when you install that one, make sure you select the correct type in your Renogy charger.

 

[Bigsidavies]

Here’s one for the battery and charging gurus.
My Renogy LiFePo was fully charged using the Victron blue smart.
After three days on the road, where the ctek has failed to kick in to charge whilst driving, my LB is now down to 68%.
However, this is the screenshot of my Renogy app. which clearly looks wrong.
Any ideas?

 

[stoic]

So what's the correct voltage? There's usually other voltmeter for the leisure batteries, ie on the plug and switches panel?

 

[waneos]

If it's done only for a few days, I don't think there is an issue and AGM should be close enough to FLD. Lithium battery might suffer more though with the wrong charge profile, so when you install that one, make sure you select the correct type in your Renogy charger.

Thanks! it has been a few months already.. but as I am going to change the battery in a few days, so it will be ok then.

 

[Bigsidavies]

So what's the correct voltage? There's usually other voltmeter for the leisure batteries, ie on the plug and switches panel?

Good thinking. Diesel heater reports 10.6v.
The strange thing is that the ctek is showing all the lights on as though it is charging the battery from both solar and alternator, yet the battery is not accepting charge.
I’m thinking the battery BMS is having a wobbler.

 

[stoic]

Thanks! it has been a few months already.. but as I am going to change the battery in a few days, so it will be ok then.

The flood charging values seem a little lower than for AGM, so definitely no damage to battery, except it has been charged slower than what it was capable of (which usually prolongs the life).

Diesel heater reports 10.6v.

That is really not good news

One question I have.. was looking at eco-worthy and they have 150 ah battery packaged in a metal box. Does that fit under the drivers seat of T6? (LHD vehicle). Has anyone tried to install it? (here is the link)

 

[Drive Wayne]

Here’s one for the battery and charging gurus.
My Renogy LiFePo was fully charged using the Victron blue smart.
After three days on the road, where the ctek has failed to kick in to charge whilst driving, my LB is now down to 68%.
However, this is the screenshot of my Renogy app. which clearly looks wrong.
Any ideas?
View attachment 230985

Any further forward Si? Bit of deja vu going on here! By now you've probably swapped out the CTEK unit and upgraded the firmware on your battery/app? Can you pump up the volume on EHU still? Are you anywhere near civilisation? Is Aly happy?! So many questions, England misses you!

 

[Dellmassive]

Here’s one for the battery and charging gurus.
My Renogy LiFePo was fully charged using the Victron blue smart.
After three days on the road, where the ctek has failed to kick in to charge whilst driving, my LB is now down to 68%.
However, this is the screenshot of my Renogy app. which clearly looks wrong.
Any ideas?
View attachment 230985

looks like you LB is flat Si,

is the CTEK fuse popped? -

or the LB voltage is too low so the CTEK wont see it.

you need to charge the LB from the EHU charger to get it back within range, then see if the CTEK kicks in.

another possibility is the CTEK has gone sideways.

 

[Bigsidavies]

Any further forward Si? Bit of deja vu going on here! By now you've probably swapped out the CTEK unit and upgraded the firmware on your battery/app? Can you pump up the volume on EHU still? Are you anywhere near civilisation? Is Aly happy?! So many questions, England misses you!

I’ve yet to check the ctek fuse, but next step after that is buying and fitting a Victron solar controller. Quick job and it will mean I can leave the ctek until I get home.

 

[Bigsidavies]

looks like you LB is flat Si,

is the CTEK fuse popped? -

or the LB voltage is too low so the CTEK wont see it.

you need to charge the LB from the EHU charger to get it back within range, then see if the CTEK kicks in.

another possibility is the CTEK has gone sideways.

Yeah LB flat as a pancake while showing 68%. It took over 100ah from the Victron blue smart.
I was being a bit dim really as it must have a drain on it that the BMS can’t see. Which is what you told me when it went flat showing 99.1%.
My problem is that the ctek is still not charging it.
If it’s not a quick fix eg fuse then I’ll buy and fit a Victron solar controller and leave the ctek. Use EHU to top up as required.

 

[nike.khoe]

Hi guys, I'm a total newbie, and have been reading this thread closely.

I currently have a T6.1 2022 equiped with an OEM leisure battery, an upgraded starter battery, and an increased alternator capacity. Additionally there is also an EOM inverter.
I am considering adding a SOK LiFePo4 280Ah to my setup, alongside a 410Watt AEG solar panel.

Based on what I've learned so far, particularly from @Dellmassive's insights (on page 10) and reviews of this thread, I have a few questions about the best way to integrate these new components.

1. Would it be better to remove the existing OEM leisure battery and the isolation relay, or should I consider adding a DC to DC converter from the leisure battery to the lithium battery?
2. Should I opt for a Victron Smart Solar MPPT 100/50 combined with an Orion XS 50A, or would the Renogy 50A system provide better integration?
3. I've also considered an Ecoflow Delta 2 with additional batteries as an alternative solution, given my novice status in this topic.

Thank you!

 

[TallPaul_S]

1. Would it be better to remove the existing OEM leisure battery and the isolation relay, or should I consider adding a DC to DC converter from the leisure battery to the lithium battery?
2. Should I opt for a Victron Smart Solar MPPT 100/50 combined with an Orion XS 50A, or would the Renogy 50A system provide better integration?
3. I've also considered an Ecoflow Delta 2 with additional batteries as an alternative solution, given my novice status in this topic.

I'm no expert to the level of @Dellmassive but I've been able to pick up some decent knowledge from here.

1. Yep, get rid of the OEM AGM. Is it under the passenger seat or is yours a Cali? If you've got the OEM split charge relay you'll need to replace this as it's not compatible with LiFePO4 batteries. If it's under the passenger seat then there's no battery that big that will fit. Max is the 230ah seat base batteries.

2. There's a few things to consider here - I'm presuming you're talking about the newer Renogy IP67 50a DC-DC rather than the DCC50S.

Obviously, the separate components will allow for a bigger charging load, 100a max combined in your case Vs 50a. Charging rate on a LiFePO4 battery should be 20-30% of the total capacity, so for a 280ah that's 56a to 84a.

The Renogy is simpler and also provides trickle charging to the starter battery. And if you get the one core display, it's basically 4x components in 2 (DC-DC, MPPT, SB trickle, BMV712).

Check the solar Voc - open circuit voltage - as I'm pretty sure a 410w panel would be above the 50v max that the Renogy can take. Again, another advantage of separate systems is that you can size each component accordingly.

3. Portable systems are a whole other kettle of fish. For me it's not an option as I also have a diesel heater (factory option) and this is powered from the LB. But for some people it's a viable option.

 

[nike.khoe]

@TallPaul_S, thanks for your insights!

1. The OEM leisure battery is located under the driver's seat of my Transporter T6.1
2. The Voc of the solar panel is 41.4V, as per the datasheet. I like simpler solutions, so you recommend to opt for the Renogy IP67 50A DC-DC charger combined with a One core display, and remove the OEM setup? How about the inverter?
3. I also have an OEM diesel heater that I now understand is powered from the leisure battery—thanks for highlighting this. If I decide on a portable system, could I potentially maintain the existing OEM leisure battery setup exclusively for powering the diesel heater? Moreover, I'm curious about the feasibility of charging a portable system from the alternator in parallel with the current leisure battery setup. Is this possible?

 

[TallPaul_S]

Ahh, I'm assuming LHD? So drivers seat for you is our (UK) passenger seat. Which is the standard location for a non California.

As above, the biggest battery you can get that will fit under the seat, is one of the 'seatbase' batteries, like the fogstar drift 230Ah:

SEAT BASE 12v 230Ah Lithium Leisure Battery

Our Drift 12v 230Ah SEAT BASE Lithium Leisure battery is 275 x 315 x 187.5, making it one of the most compact on the UK market. Priced at just £799.99 (include free shipping).

www.fogstar-drift.co.uk

With a 41v VOC on the solar panel you could use either of the Renogy units, or go for separate Victron units. All depends on cost, complexity, space etc.

What inverter do you have? Also what's the current AGM leisure battery, the 75ah std one?

Powering the factory heater from a portable system would be more complex than I'd like to consider, so best to avoid this, as you suggest. Running a separate portable alongside the factory set up might work, but I'm not sure on the limitations - if you've only got the diesel heater running off the factory LB then it could work, for sure. You'd then charge the portable system off the alternator and/or solar. The only issue might be if you're off grid for several days and using the heater a lot, with no way of topping up the factory LB (although a quick run of the engine for 20 minutes would charge it).

 

[nike.khoe]

Indeed, the driver seat is on the left. I don't need to put the battery under the seat.
I don't know what inverter I have, it's original from the factory. I think it's around 100ah.
Thank you so much for your insights!