Lithium Battery Upgrade

[Rustyrussian]

I am planning to upgrade my ‘21 310RL with two 230ah lithium batteries. We don’t have solar but we do have a residential refrigerator and the PD 2,000w inverter. I have purchased a Victron shunt to install and have 4/0 cables to wire the batteries together in parallel as well as to run to the shunt. Question is: is it recommended to go through bus bars and, if so, what rating bar should I use? I was thinking 300a. Also, do I need to upgrade any of the exsiting cables. I have no plans to go to solar at this time. Any thoughts/suggestions appreciated.

 

[BryanValRox]

I am planning to upgrade my ‘21 310RL with two 230ah lithium batteries. We don’t have solar but we do have a residential refrigerator and the PD 2,000w inverter. I have purchased a Victron shunt to install and have 4/0 cables to wire the batteries together in parallel as well as to run to the shunt. Question is: is it recommended to go through bus bars and, if so, what rating bar should I use? I was thinking 300a. Also, do I need to upgrade any of the exsiting cables. I have no plans to go to solar at this time. Any thoughts/suggestions appreciated.

Without knowing the specific details of your total electrical system, I would recommend sizing things above your expected total rating. Not sure what your shunt rating is, but you should match that for sure, assuming your actual draw won’t exceed its ratings. Sounds like you are likely already building in margin given the use of 4/0 cable.
Have you completed any testing to see what your worst case amp draw would be? This would be useful information to aid your planning.

 

[Rustyrussian]

Without knowing the specific details of your total electrical system, I would recommend sizing things above your expected total rating. Not sure what your shunt rating is, but you should match that for sure, assuming your actual draw won’t exceed its ratings. Sounds like you are likely already building in margin given the use of 4/0 cable.
Have you completed any testing to see what your worst case amp draw would be? This would be useful information to aid your planning.

Thanks for your feedback. I have the Victron IP65 shunt which is rated at 500a. I haven’t done any testing yet but primary concern is the residential fridge as we travel. We don’t boondock but we may do an overnight stop between campgrounds.

 

[Jim Beletti]

Hi @Rustyrussian,

Below are my thoughts.

If I'm following you, you have a Paradigm that came with the 2000-watt PD Inverter because the coach came with a residential (120 VAC) refer. In that case, my experience with my Paradigm was that the inverter circuit provides Inverted power for:
- Refer
- TVs
- Recliners
- 1 Kitchen outlet
- Outlets on each side of the bed

I am hearing your only change is to swap your current battery out for 2 lithium batteries and your plan is to use 4/0 cable. Good wire gauge choice for a 12v inverter.

For your battery busing, use equal length 4/0 cables to bus the batteries together. Use equal length pos/neg cables to connect to the coach DC system (see power bus bar below) using the positive off one end of the battery string and negative off the other end.

I'd also suggest you add an ANL or class-T fuse (and fuseholder) on the paralleled positive battery lead followed by a 600A Bluesea Systems HD power switch. The fuse rating will be a function of the continuous output rating of your batteries. Probably in the 200A range each. I'd probably use a 400A fuse in your case.

I believe you're asking about a power bus bar with stud terminals to connect (bus) your paralleled batteries to your coach's DC system. I'd probably use a 4-stud 300A power bus bar (1 each for positive and negative).

Your house loads (and source from converter) can connect to the power bus bars as can your paralleled batteries.

I don't see a need to upgrade any existing cabling with what you're doing.

 

[Rustyrussian]

Hey Jim, thanks for your response and recommendations. This was the information I was looking for.

 

[Jim Beletti]

Hey Jim, thanks for your response and recommendations. This was the information I was looking for.

You're quite welcome. I'm not an expert and do not do this for a living. Just drawing on my experience with my own systems. Continue to seek advice and use other sites as resources as you develop your plan.