Victron Energy: Alternator/Solar Charging - LFP Battery System

shade

Well-known member
I use switching breakers on the input and output. These protect the wire and will disconnect the power so the controller can be removed whithout shutting the system down.
I could use Blue Sea 187 Series breakers for that.

The MEGA fuses bolted to the terminals protect the bank(s) from a catastrophic failure.

No reason to use a MRBF
I'm sure that works fine, but I'd prefer some type of holder/block. Using the double lug MRBF block is also a clean way to connect the charge & load cables.
 

Alloy

Active member
I could use Blue Sea 187 Series breakers for that.



I'm sure that works fine, but I'd prefer some type of holder/block. Using the double lug MRBF block is also a clean way to connect the charge & load cables.
I needed 4 MRBF..... didn't want to spend the $$

Max voltage on a 187 is 48VDC. It will work on the output.

If your going with a 69V Panasonic panel you'll need a BlueSea A series breaker or Midnight Solar breaker.


I flush mounted everthing to protect from shorts and keep the 69V away from little fingers.
 

shade

Well-known member
Its play on words from the guys who work inside telco offices and perhaps data centers.
”Kansas City” is type of knot used for neatly supporting all the wires and cables inside those places including battery rooms.
”KCFs” are guys hired to do a job but end up not following rules, playing around, etc.
We can thank Mel Brooks for coining that phrase.
Ah, the Slim Pickens line. Got it.
 

SBDuller

Member
still a question in mind about amp hours. earlier you stated you would be happy with 100Ah, but the deal in the 160Ah just made good sense. Other than you've already chosen the 160Ah battery, would you still be happy with a 100Ah battery? I'm trying to understand if more Ah, with limited solar input, is better than less Ah, alternator charging the same either way. does 160Ah yield a better margin of use compared to 100Ah, if your needs could be satisfied with the 100Ah.
 

luthj

Engineer In Residence
For just a fridge and lights 100AH lithium is overkill with decent solar in my opinion. I could almost make my full featured overland van work on 160 ah of lithium (250AH gives me good margin).

A 50AH lithium battery with 200 W of solar and a 10 to 20 amp alternator charge circuit would be the sweet spot for simply powering a fridge I think.
 

Photobug

Active member
Back in 2016, it was standard practice to attach direct to the battery. Here in 2011, BlueSea recommended it. The name for them still is MRBF Marine Rated Battery Fuse.


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shade

Well-known member
still a question in mind about amp hours. earlier you stated you would be happy with 100Ah, but the deal in the 160Ah just made good sense. Other than you've already chosen the 160Ah battery, would you still be happy with a 100Ah battery? I'm trying to understand if more Ah, with limited solar input, is better than less Ah, alternator charging the same either way. does 160Ah yield a better margin of use compared to 100Ah, if your needs could be satisfied with the 100Ah.

A Victron Energy 100Ah LFP battery sells for $1320. The 160Ah version is selling for $1435. I have plenty of room for the 160Ah, so it was an easy choice. If the price/Ah was consistent across the line, I would've stayed with a 100Ah battery and been happy. As luthj said, my setup is overkill, but who would pass up adding 60Ah capacity for only $115?

As far as calculating battery capacity requirements against loads and charge sources, LFP changes the situation considerably compared to LA, especially if alternator charging is used.
 

Wyuna

Observer
Shade, it might be worthwhile looking at getting an extra dc-dc to parallal to get 60amps into that battery if you are just sitting around And are planning on 12 volt hot water unit

I’ve got a 30 amp Votronic Dc-dc triple charger to supply my 240ah lithium battery, and after starting to spend more time in one spot than doing huge km, I have realised that 30 amp charge isn’t enough for me

I think that an extra 30 amp an hour would be great in between spots as I use a fair bit of power with an induction cooker and 12 volt hotwater (the 12 volt hot water systems aren’t efficient), I would have gotten an Evo if I had decided to do it again, as I already had fitted a westabo diesel heater, before adding an hot water option.

yes the hot water and induction is a luxury, but we are on the road full time now, and 30 amps would be fine without these Two items.


I’m seriously thinking of swapping out my 30 amp unit to a 60amp unit when we swing past home at Xmas time, as I did over size the wiring at the time and the specs are fine for 60amp feed.

i used one of those fused buss fuses on my battery, not sure why Blue Seas don’t recommend them now.

its a no brainer to go for the 160ah version for that price.
 

shade

Well-known member
Shade, it might be worthwhile looking at getting an extra dc-dc to parallal to get 60amps into that battery if you are just sitting around And are planning on 12 volt hot water unit
I'll probably leave room on the board for a second DC-DC, but I may not need it. I'm only planning on heating a few gallons of water in a Corny keg that I pressurize for brief showers. I don't carry enough water to justify a real water heater, and I could easily start overloading my Toyota Tacoma if I started down that road. Better to tell the bather that they get two gallons, and that's it. :)
 

shade

Well-known member
I finally had time to open the battery crate, and all is well.

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The crate is solidly constructed of 3/4" plywood and didn't appear to be damaged, but the No Stack pyramid was completely crushed.

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The interior of the crate was at least half full of fill, with the battery inside a cardboard box with additional padding.

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I was a little surprised that there weren't shipping covers on the terminals. I noticed that the cardboard box had been opened, which may be part of their inspection process during some stage of shipping. The crate is screwed together, so it would be easy to open it for inspection or charging before delivery.

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Babe, the Big Blue Battery
 
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shade

Well-known member
OT, but worth it: I came across this while looking for my inspiration for an insulated battery cover.

 

shade

Well-known member
Ah, here it is. In my application, a battery will be substituted for the cookies, an insulated box will be substituted for the transparent cover, and I will play the role of Cookie Monster in the original English.

 

shade

Well-known member
I was thinking about ordering a Victron Phoenix 12V/1200VA-120V inverter, so I was poking around the VictronConnect Demo mode and found a Smart Phoenix 12V/1600VA-120V model listed, which hasn't been released yet. I'm not sure I'll like the price, but having Bluetooth on board and more power would be nice, so I'll wait on it.
 
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