Battery Trials and Tribulations

rfuss928

The Victron LiFePO4 chargers mentioned cost more than a WFCO 8735 converter and are lower charger output.  The converter manages the entire electrical system of the trailer as well as battery charging.  IMO - A much better value and a completely integrated system in the trailer.  I would change the converter.

pthomas745

Hundreds of dollars of work for 15 amps does not seem cost effective for a 100 amp hour battery.  My 60 dollar solar controller handles my lithium batteries just fine.

SLJ

rfuss928 said:

The Victron LiFePO4 chargers mentioned cost more than a WFCO 8735 converter and are lower charger output.  The converter manages the entire electrical system of the trailer as well as battery charging.  IMO - A much better value and a completely integrated system in the trailer.  I would change the converter.

No thanks.
WFCO 8735 $172.55
Victron 20A Smart Charger $170.85, 30A $182.75

WFCOs have had problems auto detecting Lithium batteries to the point where many have needed to be pulled out and sent back to the factory or modified by the user. Don't think for one minute they will charge a lithium battery at 30 amps.
The Victron smart chargers will also network with the Victron solar controllers and connect to your smart phone and can be shut down automatically by a Victron battery monitor if the temp drops below a users low temp set point.  As a backup if your WFCO craps out and won't supply DC, the Victron will also supply the camper with DC and still charge the batteries just by plugging it in to shore power.
Why I chose just adding a smart charger over replacing the WFCO with a problematic one.

Marceline

Mellow_Yellow said:

@Sharon_is_SAM. I am pretty frugal especially during winter “dry” camping. I don’t have a way of measuring daily usage. 

I think that in view of all of your "Trials and Tribulations" you really should install a Victron SmartShunt. It is super easy to install and it will give you an accurate picture of your battery's state of charge (as long as you set it up properly). What you're doing right now is kind of like going on a long road trip without a functioning gas gauge. 

rfuss928

SLJ said:
Don't think for one minute they will charge a lithium battery at 30 amps.

My WFCO regularly charges at 35 amps as soon as connected to shore power.  If the batteries are fully charged, it will quickly taper to float voltage otherwise maintains that 35 amp level until batteries approach full charge.
It takes one to two hours to remove and reinstall the 8735. The most difficult aspect is manipulating the AC breakers' stiff wiring.  Pretty straight forward one for one exchange of about a dozen wires.

Cherokee

Mellow_Yellow said:

@Sharon_is_SAM. I am pretty frugal especially during winter “dry” camping. I don’t have a way of measuring daily usage. 

If you do go with to 6v batteries, NuCamp's "guess/maybe" lights will be as accurate as they were before. An inexpensive VOM could measure the drop in voltage which determines the state of charge - just open the lid and touch the leads to the battery poles - That's frugal. One of the main advantages of Lithium batteries is that they produce the same voltage as they are depleted - so a VOM or NuCamp's lights will be of no use. However, one can deplete their charge almost completely; while AGM's drop below usable voltage as they are depleted and shouldn't be depleted  below around 50%. The price of AGM's are rising while the price of Lithium is dropping.    

Cherokee

Sharon_is_SAM said:

@Mellow_Yellow - we tow with a 2015 Sienna as well.  We will be replacing our AGM battery with lithium come spring.  We need more reliable battery life while boondocking as well. 

 To me, it sounds like you can use an easy fix.  Instead of changing converters, just install a 200 A battery in the tub and buy a lithium compatible battery charger to use at home to recharge after camping.  Follow the battery manufacturer recommendation regarding charging current.  Charging time depends on degree of battery depletion and the current of the charger.  The lower the current, the slower the charge.  You first need to measure the room in your tub to see what fits.

This is a GREAT solution with the switch that someone else suggested! I'd be tempted if I didn't have a fine solar panel and abundant California sunshine