Review RV Electrical Plan

[DryCamper]

I am planning to add LiFePO4 (LFP) batteries to the travel trailer. The existing RV power center will be changed out to support charging LFP batteries.
I will use a separate small 300W inverter from the power center to simply run a LCD TV. As there are so many 12v systems in a "camper", I will stay with 12v. In the future we may add portable (fold up) solar panels. This type of system is new to me, so I would really appreciate a review of my electrical plan before I get started. Thanks in advance. Mike

 

[John Frum]

Are you sure your existing converter isn't able to charge your lfp batteries?
Many can.

 

[John Frum]

Watch out for a power loop between the inverter and the converter.

 

[DryCamper]

Watch out for a power loop between the inverter and the converter.

No problem here, the inverter will not power all AC in the RV, just a dedicated connection to the TV.

 

[DryCamper]

Are you sure your existing converter isn't able to charge your lfp batteries?
Many can.

I am not sure at all. Per the manufacture manual, it only supports LA batteries and they have a different model unit with a switch to charge LA or LFP batteries. I know the desired charging "curve" is different for LA and LFP and I have read that LFP do not like the float voltage level. But I am totally new to this, so I really am not confident. I submitted the question to Battle Born early last week, but have not received a reply. I have attached the page from the WFCO manual with the 2 charging curves.

 

[John Frum]

I am not sure at all. Per the manufacture manual, it only supports LA batteries and they have a different model unit with a switch to charge LA or LFP batteries. I know the desired charging "curve" is different for LA and LFP and I have read that LFP do not like the float voltage level. But I am totally new to this, so I really am not confident. I submitted the question to Battle Born early last week, but have not received a reply. I have attached the page from the WFCO manual with the 2 charging curves.

Is that doco for the new converter or the existing converter?
I would think that either of those charge modes would work.

 

[DryCamper]

Is that doco for the new converter or the existing converter?
I would think that either of those charge modes would work.

WFCO is the company manufacture. The old power station only generates the top curve for LA batteries. The new power station has a switch to select LFP batteries and would then generate the second curve if selected.

 

[Cdkipp]

I am not sure at all. Per the manufacture manual, it only supports LA batteries and they have a different model unit with a switch to charge LA or LFP batteries. I know the desired charging "curve" is different for LA and LFP and I have read that LFP do not like the float voltage level. But I am totally new to this, so I really am not confident. I submitted the question to Battle Born early last week, but have not received a reply. I have attached the page from the WFCO manual with the 2 charging curves.

Battleborn lists compatible chargers on their website.

 

[Cdkipp]

What shunt and meter are you using. Shunts are typically on the negative side.

 

[Cdkipp]

There is typically a fuse between battery and other components. Ideally, that would go right before your switch. I suggest a blu sea switch. You may want to look at their fusing.

 

[Cdkipp]

How long are dc wire runs. It wouldn't cost much to size things up a bit. I know a 300 watt converter isnt much but something to think about if you are going to have longer runs or size things up later.

 

[Cdkipp]

Your inverter dc input is just kinda hanging out on top there. You intend to run DC wires from busbars to the inverter. Your shunt will be before busbars so it picks everything up.

 

[DryCamper]

Dhasper, thank you for your comments.
1 - Shunt location, I will have to review that. For my system, moving it to the negative side will be difficult due to the batter physical locations. I am curious as to why this would matter in a DC circuit? Hmmmm.
2 - Fusing, good idea. I will add fusing or at least a CB for each battery. Will likely remove the single CB then as it will not add much value
3 - DC power runs, this is an RV (travel trailer), there are DC runs existing everywhere. The power center distributes the DC and each circuit is fused. I am adding one additional circuit from the power center for the small inverter. The max available fused output is 30A, so there will be no up sizing without a complete rework of how the RV is powered.

 

[Cdkipp]

Dhasper, thank you for your comments.
1 - Shunt location, I will have to review that. For my system, moving it to the negative side will be difficult due to the batter physical locations. I am curious as to why this would matter in a DC circuit? Hmmmm.
2 - Fusing, good idea. I will add fusing or at least a CB for each battery. Will likely remove the single CB then as it will not add much value
3 - DC power runs, this is an RV (travel trailer), there are DC runs existing everywhere. The power center distributes the DC and each circuit is fused. I am adding one additional circuit from the power center for the small inverter. The max available fused output is 30A, so there will be no up sizing without a complete rework of how the RV is powered.

Yes. I also RV fulltime. I increased the size of the new DC wiring I put in but I agree it feels pointless when connecting to the smaller rv wiring. I had to do it as I have a 3000 watt inverter. Are you thinking of just using the existing voltmeter? I don't know the exact reason ammeters are placed on the negative side. I know one of the BMS makers, (maybe chargery?) wants a shunt on the positive. If you look at the brands like the bogart trimetric, the Victron 700 series or even the Aili Chinese meter, they all tell you to install on the negative. I relied heavily on this site when I did my system. many more resources these days. http://www.jackdanmayer.com/rv_electrical_and_solar.htm