Lithium Upgrade In Process-Help Please

[genesis379]

New to us 2015 Fleet Side Dinette

We are currently changing from (2) 6v batteries that did not have a controller/monitor installed to lithium. We are using a renogy lithium battery and their DC/DC MPPT charger/controller.

My question is- going from the new lithium battery to power the camper, should I hook up to what is already existing (see picture) or get rid of the battery separator and fuse? If I do scrap it, what should I use instead?

Thanks for your insight.

 

[alano]

Sadly, there isn't a picture. When I did pretty much what you're doing (2 12 volts instead), I eliminated the battery separator since the DC/DC takes care of that. You definitely want a fuse between the charger/controller and your truck battery. Renogy docs should tell you the size of this fuse. I have fuses (breakers actually) in the camper and under the hood both so that I can depower (is that a word?) the system from either end if repairs or replacement is needed. I also have a fuse (actual fuse) between the charger/controller and the battery. This one is 40 amps since I have a 30 amp charger.

Congrats on upgrading your rig. I've been very happy with my lithium battery and DC/DC MPPT charger/controller setup and I think you will be also.

Alan

 

[Vic Harder]

As Alan said, use a DCDC instead of the separator. I'd also get a Victron Smart Shunt to monitor your new battery's status, and see how that goes. Do you have solar? What is your shore power charger?

 

[CreekRob]

Are you using existing wiring? DC to DC charging with lithium can take quite a bit of current; I formerly used a Kisae DMT1250 and had over 40A coming from the engine bay. IIRC FWC used rather slim wiring and it might not be up to the challenge. And check the alternator too. The up side is that it can charge those lithiums quite quickly.

Do not get rid of a fuse, but make sure it's the proper size to protect the wire and the current used.

 

[Vic Harder]

Are you using existing wiring? DC to DC charging with lithium can take quite a bit of current; I formerly used a Kisae DMT1250 and had over 40A coming from the engine bay. IIRC FWC used rather slim wiring and it might not be up to the challenge. And check the alternator too. The up side is that it can charge those lithiums quite quickly.

Do not get rid of a fuse, but make sure it's the proper size to protect the wire and the current used.

+1 to bigger wire. 6AWG mininum, 4AWG or thicker is better.

 

[Stretch8045]

Help Please !
I am doing a cross country rv trip. I had 2 , 100 amp LifePo4 batteries & charger delivered to our campground do to killing my 2 100 amp deep cy. lead acid batteries while boondocking
( my cpap needs killed them )
I have a 190 W roof mount solar panel and would like to add a 200 W portable later. Can I full charge the LifePo4’s and install now then upgrade needed stuff when back home later ?
Being new to RV electronics, what does a inverter do vs converter, etc.

 

[Vic Harder]

Help Please !
I am doing a cross country rv trip. I had 2 , 100 amp LifePo4 batteries & charger delivered to our campground do to killing my 2 100 amp deep cy. lead acid batteries while boondocking
( my cpap needs killed them )
I have a 190 W roof mount solar panel and would like to add a 200 W portable later. Can I full charge the LifePo4’s and install now then upgrade needed stuff when back home later ?
Being new to RV electronics, what does a inverter do vs converter, etc.

Yes, you can install the LiFePo4's now. Use them until you get back to home base and then look at:

1) Adding a real Battery Monitor. The Victron Smart Shunt is a good bet
2) Changing the solar controller or the settings of your controller
3) Adding stuff to enable shore power charging or vehicle charging as needed

As for definitions:

4) Inverter = takes 12V from batteries and changes it into 120V for household appliances
5) Converter = takes 120V "shore" power and charges your batteries.

 

[Stretch8045]

Thanks, after giving my vin number to Forest River they said that the existing OEM either inverter or converter ( is that the same as controller ) was not adequate to transfer enough power from the existing 190 W panel if I was to add an additional 20” W portable panel.

 

[Vic Harder]

yes, from what I am interpreting from your and their comments, that is the controller they are talking about. Adding another panel would be a "later" and that would potentially include looking at what controller you have and upgrading it or adding another.