It’s been a couple of months since we bought our solar power system and we’ve noticed a big problem that seems to run across the DIY industry: the kits don’t have a built-in low voltage disconnect (LVD) for the AC part of the set up.
Solar kits run both AC and DC loads. The AC is the one you would use for your home. It’s strong enough to run the big appliances. The DC is stuff you run right off of your batteries like when you go camping.
With batteries, if you deplete them too much, they become damaged and their lifespan is shortened significantly.
Our solar power kit came with charge controllers that have a low voltage disconnect (LVD). It cuts the draw from the batteries at a certain voltage to protect the battery but ours only turns off the DC load – the part we don’t use.
The inverter that came with our solar kit turns off the load at 10.5 volts – way too late.
Because we thought everything was being monitored, our batteries ran well below fifty percent many times. We wonder if they’re ruined.
I bought a generic LVD from another company and installed it but it stopped working, possibly because it couldn’t handle the amount of amps going through it. I was warned that might happen.
We had to remove the relay so the inverter would work again but now we are back to square one. One option we have is to buy an inverter that is programmable but they’re super expensive. We now have no way to monitor the batteries but we kind of don’t care. I’m tired of messing with this stuff for now. I need a break so we’re back to using the gas generators until everything is running smoothly.
Here’s another thing to be aware of if you live in an RV: when you’re adding up how many watts the various appliances use per hour, don’t forget you’re charging the RV batteries also.
I had a ball trying to figure out how many watts it takes per hour to charge fifty percent of two batteries. I’d share the formula but I lost the paper with my notes on it.
The solar kits come with a battery thermometer that plugs into the charge controller. The temperature probe gets taped onto the side of the battery to let the charge controller know how much energy to use to charge the battery, depending on whether it’s super cold or hot. They’re not mandatory but they make charging more efficient.
There are a lot of variables that impact the functioning of a solar power system. If one part isn’t running or working well, there goes the whole thing until you track down the problem.
I believe a low voltage disconnect is the most important part by far. Batteries are expensive. Every DIY kid should have one built into the AC part of the system.
I love having solar but the truth is it’s been a huge pain in the but to set up properly.
This poem says it all: Rant Poem On DIY Solar