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The AikiHomestead

Our Lifestyle Blog as We Create a Homestead in Northern Ontario

Switching From AGM To Lithium Batteries


A month into 2022 already and I haven't put out a new blog post!

It isn't actually that I'm not working on the blog. I've been working hard at going over all (and I mean ALL) my old posts and trying to update them on the new website. I know it's hard to see the difference, but it does take time and work. I've spent a few days just re-ordering all the posts in chronological order, which I can't believe it never was in the past. Now only the latest post will be in this special "frame" and then it will get moved to the bottom of the page, so readers can have a coherent story.

Feel free to discuss, but that's not the point of this post!

As December deepened, it became clear that either my Trojan AGM batteries were defective, or I had inadvertently abused them, or that they were simply undersized for the sort of loads that we need here. In any case, I was running the generator several hours every morning to get us through until the sun shone on our panels. Even on a morning where the previous day had been full sun and the batteries had spent hours in absorption, they were nearly depleted after an evening with the power turned off.

Bringing Donna up to speed on the situation wasn't difficult, as she was aware of how much the generator was running, and how many nearly weekly trips I was making to fill our gas cans.
Man carrying a box in the snow.Open cardboard boxes.Batteries and cables beside a Chesterfield.Circuit breakers on batteries.Network ports on batteries.After some research on the matter, and emailing back and forth with Steven Rousseau at Volthium, I went ahead and ordered two of their 25V, 200AH rack mounted batteries.

Steven's support was excellent throughout, and I hope he knows how much I appreciate his patience with me, even as I was becoming more and more needy.

I note that the batteries currently suggest that they would have Bluetooth capability by the end of 2021. I purchased mine in December, but I don't see that they have this ability. Perhaps the current ones do - confirm for yourself if this is a requirement (it wasn't for me).

Instead I noted that they have the ability to communicate via the RS485 standard. This turned out to only be partially true - they certainly didn't communicate with MY RS485 adapter, but purchasing the official one from Volthium worked immediately. I think they prefer one to use the CANBUS, but I already had a small "server" in the attic where I store the batteries, so I didn't want to add another device if I could help it. Especially since Victron units are rather dear.

This little hitch meant it was about a month after ordering the batteries before I actually got the cable shipped (separately) and installed, but in the end it was all fine. I actually went as far as to install a cheap webcam in the attic to monitor the four LEDs on the front of the batteries in the meantime.

Since they've been installed (about three weeks ago) I haven't needed to run the generator at all. Of course, we've had unusual amounts of sunlight, but I'm comfortable running these batteries down to 20% capacity if needed, instead of the 50% that one usually aims for with conventional lead batteries.

Another property of the lithium batteries that I don't see discussed much, but which is to me an amazing advantage, is their short or non existant absorption time. With my regular lead batteries, I was missing out on utilising large amounts of my available solar power on sunny days. As soon as the lead batteries reached the absorption voltage, they immediately began 3 or more hours of constantly reducing amperage. We knew in our household to suddenly start using extra power on cold, sunny afternoons if for no other reason than it was just being "wasted". It's frustrating when you know your batteries won't be there for you the next morning, and yet in full sun in the previous afternoon, they're only allowing in a few amps.

Lithium, on the other hand, just keep sucking down all the power you give them until they are as full as you want them to be (or 100%, whichever comes first). They are more efficient at charging as well.

This property of them not turning down power available is huge for me in winter when short, but intense bursts of power are the rule.

I opted to purchase the busbar as per Steven's recommendation, and that's another win. It is far oversized for my needs, but it certainly makes connections far neater and safer.

That's about it. It's another overcast day here today, and I can log into the batteries and see that they are precisely at 68% - normally I'd be debating if I run the generator now, or wait until the morning to go out and pull the cord in the cold and darkness. Instead, I'm confident that I could go another day or two and even consider running appliances without batting an eye.

I haven't yet put them to the test with an electric kettle or my induction stove, but I can't see a problem doing so. They already power the water pump, washing maching, slow cooker and rice cooker without missing a beat.

I will absolutely keep everyone abreast of these new additions to the homestead - they certainly weren't inexpensive, but if they live up to their hype, I will consider them to be absolutely worth the cost.
Busbar.Man viewed through an attic door.Busbar , batteries and electronics.Networking cables in batteries.Batteries and cables.Cables plugged into the USB ports of a miniPC.Inverter, distribution panel, mini PC, solar controller, bus bar and batteries.Legs hanging down from an open attic door.

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