RC Electronics, Inc. "Watt's Up" WU100 DC Watt meter and Power Analyzer (Blue)

I was running this between a 5A 58.8v charger and a 14s (52v) ebike battery that has a 35A BMS. The display started going all wonky, and confident of the warranty I contacted the company. They refused to even look at it, and said I was overvolting the thing. It's rated at 50A sustained, 100A peak, and 60v, but seems to only run okay at less than 55v. It's rated crap as far as the company goes. Don't waste your money. Buy two $7 bay Chi-com RC power meters instead.(UPDATE: I've been using it on a 13s/48v battery charger that uses 5A and goes to 54.6v charged. maybe this unit just doesn't like 14s/52v/58.8v systems. As far as the Chi-Com RC power meters they are okay for a charger but die shortly if you run them in +/- power lines of 30A e-bikes. probably the best bet is to use a shunt on anything that isn't a charger. I.ve adjusted my feedback to a 4* as unlike the cheap meters it is still working and I no longer regret my purchase but my expectations were maybe a little high. This is ideal for 48v/13s/54.6v or less lower-powered i.e. legal e-bikes or chargers for power consumption monitoring).

I've had my Watts Up V2 meter for years. It's excellent for hobby stuff and quick measurements. I installed anderson connectors on the ends and frequently use it to measure solar panel wattage when charging small batteries, or when running small inverter loads. It has very low power requirements and it's great in these use cases.However, I would be willing to pay more for a more robust meter for hot and longer term environments. I have solar panels on the dash of my vehicle, charging my 12V battery so it never dies, no matter how infrequently I drive it.Often, if I leave this meter plugged in for more than 24 hours it has "blacked out". The LCD shows solid black bars rather than measurements. Unplugging both ends of the meter and replugging resets the meter successfully every time, but it's annoying.Again, I understand this is a hobby meter and I am very much using it in a fringe case here. I just wish it handled longer term loads and hot environments a little better. I'd totally be willing to pay more for a similar meter with better long term reliability. There are marine meters out there that may be more reliable, but I haven't found anything meant for small loads that has a wattage display. Usually they are just amp and volt outputs and I have to do math. I'm lazy. Take my money.

Pretty good little meter and very accurate. There are a couple things the buyer should be aware of:1. The meter "shuts itself off" once your power source goes away and has to be restarted every time or it won't work. I put a power switch I got at the auto parts store and put that between my panels and the Watts Up meter as a quick "reboot" when I want to use it again the next day. This could be achieved with a breaker as well. Otherwise, you will have to physically detach the 14 guage wire from whatever it is connected to and connect it again. Pain in the rear!2. The wire connected to it is very short and pretty cheap. You will most likely need to solder it to another wire and connect it to your panels or battery that way.3. For those newbies to solar out there, It does NOT tell you your battery voltage AND your panel input voltage. If you want this you will need to buy two Watts Up meters and hook one between your panels and the charge controller and one between your batteries and the charge controller. This may also prove to be not accurate on the battery side so your probably better with a Bogart Trimetric for something like this.Other than that the meter itself is pretty awesome internally. Super fast and easy to read.

I use this to monitor the instant and daily energy production of my solar panel with storage battery. It's exactly I need and works perfectly.Pros:- Works great- Simple to use, and excellent instructions (with more on their website)- Seems well made, robust, good thick wires- Great features - I especially like the cumulative and min/max readings. Also easy to reset, and so get daily energy production.Cons:- Smallish screen with no backlight. No reading this thing from a distance- No way of getting data out. Strongly recommend that manufacturer adds pin-outs or USB plug to enable external data. Bluetooth would make this device magic.I saw some questions about how to get this to work with a solar panel/battery system. According to the instructions and my experience: Connect the black wire of the "source" side (the side with the pins) to the negative terminal of the charge controller. Connect the black wire on the non-"source" side to the negative terminal of the battery. Connect the positive terminal of the charge controller to the positive terminal of the battery (like normal). Connect the red wire of the "source" side to the positive terminal of either the charge controller or the battery - this wire can be thin since it is only measuring voltage, not conducting power, and if you add an in-line switch to it then you can easily reset the Watts Up measurements by briefly turning the switch off. The red wire of the non-"source" side is not connected to anything.