The battery makeover project is going to start this weekend! There are a couple of phases to it.
I have just completed the ‘research what I need and get all the pieces’ phase. At first, I was completely overwhelmed by the whole thing. But with a solid knowledge base about 12V systems, I was able to keep reading until things made sense.
Now, no laughing at my lack of graphic design skills, but this sketch should give a general idea of how my 12V battery bank is going to be wired once I’ve added all the new items:
Here are are all the electrical components I need just at the battery bank to make this happen and get my inverter hooked up:
Going left to right, starting with the blue (now black) cables at the top. These are 12″-long 1-gauge cables from Canadian Tire, part #011-1091-0. They have round terminal ends for fitting between a nut and a bolt. These blue cables were replaced by part #11-1088-0, which has round terminal ends at both ends, with the shortest size being 18″. These will go between the shunt and the negative terminal on the inverter and between the fuse and the positive terminal on the inverter.
Next are the black cables, which are 3′-long 1-gauge cables, Canadian Tire part #011-1032-2. They have heavy lug at one end that goes around the battery post and a smaller looped terminal end to go between a nut and a bolt. One will go from the negative terminal of my battery bank to the shunt and the other will go from the positive terminal of the battery bank to the fuse.
(I already have the cable that creates the series connection between my two batteries.)
So between the two cable lengths, I have four feet to get from my battery bank to my inverter, which will limit where I can put it, but will mean very little resistance and therefore less of a voltage drop. The inverter manufacturer recommends 4-gauge cable with a maximum length of 6′, so I am well above the recommended specs.
I did a lot of research and consulting as to where to find battery cables and the end resulting was very overwhelming, complicated, and expensive. The Canadian Tire cables are well made and I paid $75 plus tax total for all four.
Next, the long silver thing is a 150 amp fuse and holder from Northern Arizona Sun & Electric. These folks have great service and competitive prices, but I won’t be ordering from them again from Canada because they ship through UPS, meaning I have to add a nearly $50 brokerage fee to my order on top of the more expensive shipping price than if they used USPS. I will be getting a back up fuse from them when I am in the States this winter, however!
Sizing the fuse was a little counter-intuitive, but once I thought about it, it makes perfect sense. Basically, you want a fuse that can handle your maximum load and not blow early, but it can’t have so much capacity as to allow a damaging load to pass through.
Having a 1,000 watt inverter with a surge capacity of 2,000 watts, that means I could have as much as 167 amps (2,000/12) going through my system at one time. That said, I know I will not be running anything with that kind of load in the foreseeable future, so the 150 amp fuse is sufficient. It’s not that expensive of a part, so I always have the option of replacing it with a higher rating later if need be.
Note that the solar panel has its own fuse. I vaguely understand why, but you can check out this discussion for more details.
The short silver item and round thing next to the fuse are the shunt and the battery monitor. They come together. I bought a Xantrex LinkPRO battery monitor simply because I had sufficient Amazon gift certificates to cover the cost. The PRO’s main additional feature over the LITE model is that it gives you the amount of time left at your current rate of consumption instead of just the amount of battery life as a percentage. That information would have been worth the $40 price difference even if I had been paying out of pocket.
The shunt is connected to the negative side of the battery bank and monitors all the energy into and out of your battery bank to determine your consumption.
The coiled wire is the Xantrex Connection Kit. Electrically savvy RVers with a source for parts would find it much cheaper to make their own connection kit. But for a newbie, this kit apparently makes the installation fool proof. There is some assembly required, but everything is colour-coded. I am going to start the assembly this weekend. Since I essentially got the monitor free, the trouble of researching, finding the parts, and making my own connection kit just didn’t seem worth my time.
Finally, at the bottom, is my new 1000 watt pure sine wave inverter.
This weekend, I will enter the ‘assemble the battery monitor’ phase and start on the ‘put it all together’ phase.
Next nice weekend that my mother is available, we’ll move into the ‘finishing putting it all together, set up the inverter in the living room, and bring 120V power from the inverter from the living room to the study via the rig belly and then finish all the trim along the floor in the rig’ phase.
Finally, sometime this fall or winter, when I am in the US, will finish up this project with the ‘install two new Trojan 6V batteries and a battery watering system’ phase.
I sure have come a long way in my electrical knowledge in the last four years and I am starting to apply this knowledge to the 120V world, too. One thing I love about RVing is that it gives you the chance to learn so many new skills if you want to. Now, I like paying someone to do work as much as the next person, but it’s nice to know that you could have done them.
Well, it’s going to rain again, so I won’t be starting today.
Dave says you have the solar panel connections on the wrong side of the fuse and shunt. Your battery monitor will not detect the additions from the solar charging. Otherwise, good job.
Good catch!!! I know better! (it’s fixed now)
Just curious why the new batteries and watering system? From your praise for AM Solar and what they have to say about batteries – “We’ve been using Lifeline AGM batteries for the last decade” why are you not going with AGM batteries?
In order to perform well, AGM batteries have get a full charge regularly in order to maintain peak performance, and they must never be over charged. To put it another way, they want to be charged just so. Since I rely on solar for charging (no gen set as a backup), I can’t guarantee that my batteries will get the proper charging regiment. AGM batteries are much more expensive than the flood cell type I currently have, so these charging requirements make me reluctant to use them.
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