Switching From Wet Cell Deep Cycle to LiFePo System - Insights?

[coqcitywesty]

So I originally posted this query to the 'Official Lazy/Stupid Questions' thread, but after not a lot of feedback, I thought it might deserving of its own thread as I cannot imagine that I am the only Vanagon owner in the same position.

Here goes:

Sooooo.....yes, I am aware that there is a 46 page dedicated LiFePo thread and while this thread appears to be more oriented towards those much more willing to build and balance their own batteries and system, my Westy currently has a plethora of Blue Sea Systems components with an onboard charger (Promariner 12) and solar set-up (Renogy 100W w/controller) already in place for a wet-cell deep cycle battery (See wiring diagram below). I have been running a Group 27 120AH Kirkland battery mounted under the rear seat that usually lasts me a couple of days before needing a recharge and that I replace every 2-3 years, but given that Kirkland (Costco) has now changed this battery to a 100AH option, its time to upgrade to a turn-key LiFePo option with at least 100AH with a built-in BMS. In short, while I am relatively adept at 12V wiring, I am looking for a simple, turn-key solution, noting that the existing system and wiring has served me well for the past 8 years.

To this end, given the components/wiring that I currently have in place, what new components do I need to remove and then acquire/install to support a LiFePo battery to allow it to be charged via the alternator, the house system (ProMariner) and the Renogy solar panels?

Any/all insights are welcomed as are PM's. Thx in advance.

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1991 Westfalia EJ251, 1972 Volvo 1800 ES

[dobryan]

What battery chemistry do your 3 chargers support?

If LiFePO4 is one of them then you should be good to go. Just be sure to set them for LiFePO4.
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Dave O
'87 Westy w/ 2010 Subaru EJ25 (Vanaru) and Peloquin TBD

"To travel hopefully is a better thing than to arrive." Robert Louis Stevenson

MD>Canada>AK>WA>OR>CA>AZ>UT>WY>SD
https://www.thesamba.com/vw/forum/viewtopic.php?t=620646

Building a bus for travel in Europe (euroBus)
https://www.thesamba.com/vw/forum/viewtopic.php?t=695371

The Western Syncro build
https://www.thesamba.com/vw/forum/viewtopic.php?t=746794

[kamzcab86]

[crazyvwvanman]

A diagram without wiring sizes shown?

There are various issues in what is shown I'd say.
Not enough fuses.

I would want a suitable fuse on the Lifepo + terminal so nothing connects to the battery + without pass through the fuse.

Deciding fuse size is one place where knowing wire size is essential.

Mark

[DanHoug]

i'm not keen on starter/aux battery switches when using lithium... the BMS of lithiums restrict the output current to 100 amps. while it MAY start your vehicle, if you simply isolate the loads on the #3 fuse in addition to a headlight alarm, there's very little chance to run down the starting battery while saving a whole bunch of extra wiring. if you really want a backup to the starting battery, simply carry a small inverter and battery charger or a jump pack.
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-dan
60% of what you find on the internet is wrong, including this post.

'87 Westy & '89 Westy both 2.1 4spd

Past projects can be found at--
www.thefixitworkshop.com

[coqcitywesty]

To follow-up and after checking, my onboard charger is a ProMariner 12 that is only compatible with wet cell or AGM batteries (2018 vintage) so that is definitely out, whereas my Renogy 100W panel has a 20A PWM controller that is compatible with a LiFePo battery. As for the wiring gauge query, as the ‘system’ was originally designed by an electrical engineer colleague, (now retired) so I am confident that it is more than sufficient to handle the load, but more than happy to add in additional fuses as need be. I am not committed to any part of the existing system, rather I am looking to re-design to support a turn-key LiFePo battery, noting that I am currently eyeing the Renogy 200AH option:

https://ca.renogy.com/renogy-core-mini-12v-200ah-l...rotection/

For example - not clear where the DC-DC charger gets incorporated and what it replaces? The ProMariner? Obviously, I am needing to also retain my wet cell starter battery..

Again, any/all insights are greatly welcomed and appreciated.
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1991 Westfalia EJ251, 1972 Volvo 1800 ES

[jimf909]

[coqcitywesty]

Thx Jim -

200AH would absolutely take care of my power needs for 2-3 days which would eliminate my need for solar. The house charger (currently) is kinda key to maintaining the overall health of both my starter and house battery, especially over the winter as would be the ability to recharge while driving between locations, which means a DC-DC charger as well. I am narrowing it down, so thanks for the insights.
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1991 Westfalia EJ251, 1972 Volvo 1800 ES

[brianu]

The original diagram seems complex. Is there a reason for keeping all the different components and not just reducing and de-complexing?

For what its worth... I have the stock starter batter in the normal position;
From the Starter I have a run to a Renogy DCC50S (DC-DC + Solar MPPT) (200W flex Panels on the Roof) and a 100W LiFePO4 Battery in the rear storage cabinet (next to the plugs and watertank).

The Battery has a run up to the former house battery location where I've put in a BlueSea fuse block as the distribution point for Fridge, Stereo, Cigarette PowerPlugs, random lighting; etc.

The critical dash points are all on the normal power+ fuse into the dash off the starter. (seperation of pleasure and functional)

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1985 Vanagon GL Westfalia - Bronze Beige Metallic - Engine: 1990 Subaru EJ22 - GoWesty Syncro liftkit - Poptop Struts - 135AH of house batteries

[coqcitywesty]

Thanks again to all for all the insights - greatly appreciated.

Where I/we netted out is as per the following diagram (and yes, I am aware that wiring specs are not included ). This will give me the ability to charge both house and starter batteries from shore/solar/alternator. All in, it will likely set me back $1500 - $1600 for the battery and other new Victron components + wiring, so I am thinking I will 'wet-cell-deep-cycle-it' for the balance of the Westy season and upgrade over the fall once I have saved some more pennies. I will update accordingly. Again, thanks.

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1991 Westfalia EJ251, 1972 Volvo 1800 ES

[danfromsyr]

take a look at this Renogy dc-dc charger.. you might be able to eliminate some of the victron components combined in the functions of this unit.


https://www.amazon.com/dp/B093BB5JKF?th=1

User Manual with specs etc. (Charging logic on Page 16)
https://m.media-amazon.com/images/I/91uS4w8LWRL.pdf
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