Coolschmax Waterproof IP67 Battery Tester 10-100V with 100A Shunt Energy Saving Capacity Monitor V/A/SoC/Ah for Lithium, LiFePO4, Lead Acid, Solar Batteries and Others in Golf Cart, Car, Motorcycle

I use a power wheelchair. It has used lead acid batteries since new, but they only last 12 to 18 months. I got a bit longer with a premium battery but it's a hassle to change them as you have to remove the seat to access the battery box, and then open the box and exchange the heavy batteries. I had considered Lithium batteries but they were priced out of my range.Then one of the major battery makers offered a set of LIFEPO batteries for about $35 more than the lead acid ones. They had 15 more amp hours and weighed less than half as much. I was required to purchase a LIFEPO charger as the one that came with the chair didn't put out enough voltage to properly charge the new batteries. The new charger has a harness and disconnect plug that connect directly to the batteries as the original port couldn't support the load.After I installed the LIFEPO batteries I ran the chair watching the capacity display on the Shark controller but after a week of use it still showed 100%. I figured that it wasn't accurate due to the different discharge curve of the Lithium batteries and this was proven correct when I connected the charger. I don't know what it was down to but it took a few hours to fully charge them.So I was browsing the meters when I came across this one. It would handle more voltages and battery types than most of the others, and it was water resistant in case you get caught in the rain or water splashes out of the sink. It has many types of battery profiles built in, but in case non of them works it has a custom section where you set the minimum and maximum voltages and it uses that instead. The LIFEPO batteries I purchased were in the latter category since they were designed to be as compatible as possible.The first thing you have to realize is that a very small voltage change indicates a fairly big drop in capacity as the LIFEPO batteries tend to have a close to flat curve until the very end. So after charging it will indicate 100%, but when you push the joystick the display will go down to maybe 75% or even lower at higher speeds, but when you stop it climbs back up to 100% at first, then as you continue to use it the percentage goes down.The meter will display percentage of charge, or if you press the button once it changes to the voltage display. There is a port with a sealing plug in it on the back so you can calibrate it with an accurate voltmeter and it remains accurate at different levels across the range.It has a nice backlight but you can turn this off if you are concerned about the drain or just want it dark by pressing the button twice. The display is very clear indoors but washes out some when outside but is readable, but you have to look at it more closely to make it out. When the backlight is off the meter draws 1 milliamp. It doesn't draw much when on.The button IS a bit stiff to press but I'm hoping it gets easier with age although once set up there isn't much need to press it.The main disadvantage I've encountered is that the one button does EVERYTHING. You set all the parameters with it so you have to do some careful pressing to set it up. However it has flash memory so it retains all your settings when disconnected from power so you won't have to do this multiple times.I was a bit concerned about how I was going to wire it up. I didn't really want any long wires running down to the battery pack and I suddenly realized that the charger port in the Shark controller had two wires that went to the battery in order to charge the old lead acid batteries. I had an extra connector for this port so I checked the charger one to see which was positive and negative and wired the meter into the spare connector and just plugged it into the charger port and it works perfectly and I didn't have to modify the wiring of the chair at all. I had a metal bracket left over from another project that I fastened to the arm of the chair. The meter has a threaded shaft and a wing nut to mount it to your installation. I can have the meter unplugged and off the chair in less than a minute. The bracket will take a little bit to remove but I felt like this was a winner.I have had good luck with this meter and would recommend it to anyone having a need for a way to monitor their batteries state of charge, regardless of the type of battery.

Installed this to replace an old, ugly LED battery indicator on our old, ugly AF golf cart that we only use to tool around for fun w/ the runts.Installation was easy, using standard twist wire connectors, electrical tape, and some 3M tape to mount the actual monitor to the old metal mount already on the cart.Knocked one star off only because it's fairly small (smaller than I expected) and should have come with some better wire connectors on its own, such as the Lever Wire Connectors you can find on Amazon. Overall, though, price is right and it seems to work just fine, providing accurate information in a nice, readable fashion.

I purchased this so I can monitor the capacity left on my trolling motor LiPO4 batteries. The issue with these batteries is they always report the same voltage so there is no real way to know how much capacity is left. I tested this unit on my bench with a power supply and a couple automotive lightbulbs for the load. It works as advertised when the load is connected the gauge goes down appropriately based upon the amps being pulled and when the load is disconnected but the power supply is still connected the fuel gauge goes up like the unit is charging. Setup is generally easy but the documentation could be a little better but not hard to figure out.

Very easy install and set up. Good instructions.

This is the second one I purchased for another project. I like manually setting the battery curve for better accuracy.

The function of this device is exceptional. It is now installed on my Genie lift, monitoring the 24 volt capacity of the battery bank. However, the installation was a challenge that should not have been required. This device is clearly designed to be flush mounted as most other gauges; the installation video is an insult to the product. Nowhere is the dimension for the round mounting hole. A purchased 55mm hole saw works fine. The connection wires are truly laughable. ~26 gage encapsulated in a solid sleeve, bonded to the wires so tightly that any attempt to separate them results in compromising each conductor insulation. Unfortunately, the sellers/developers clearly have never attempted to install this great product.

Used it on a golf cart. A 55mm hole saw I also got on amazon was a perfect fit. Connected it to the battery with a 2 amp inline fuse. Programming is kinda a pain ( its hard to get it to leave the settings menu ). This is a 2 wire voltage gauge, so it doesn't have the ability to turn off when the ignition is off on your golf cart. It's always on. But if you double quick press the button it shuts off. I just leave mine on, it uses so little power. If i had to do it again i would spend a-little more and get the better one which has a sensor inline for the battery and the 3rd wire to shut it off. But for something other than a golf cart it works perfect. I gave it 4/5 stars cause it isn't a true golf cart voltage gauge.

Excelente producto por su funcionamiento