B0138c

I bought the 100A + 100A/75mV shunt - Useful in helping prolong the life of my leisure batteries. Because I have a 95AH battery (total ~ 1100 watts), when the energy shows 600w after use following a full charge, I know I am around 50% discharged and can switch batteries. For those who don’t know, a cycle of 50% discharge followed by full charge is recommended to extend battery life. If, like me you can’t afford full Vitron kit then this is very useful to monitor battery usage. It measures energy consumed rather than load voltage as some do (some meters show a percentage battery consumption based on load voltage) so it can tell me when I’ve used 50% of my leisure battery. For those with solar kit, the energy used number won’t help much on its own if you are solar charging. You will see battery drain current and load volage which is still useful but because it doesn’t show current flowing into the battery only out and therefore it’s difficult to work out charge state. (You could use several units but I haven’t tried multiple units) Before I put this in my self-build motorhome, I thought I would test it as the shut resister looked bent. I have 2 leisure batteries; one a 95 Ah 12v wet acid by Bosch and one an import brand 110Ah AGM. I have a switch to connect 1 or 2 or both. The idea being that I charge them fully, reset the meter (hold down the button until it says reset) then use battery 1 on its own until energy reads 600w then switch to battery 2. As most our trips are off mains, short trips I suspect I am draining one battery too much by switching after 3 days as I do now. The picture shows my lab bench PSU throwing out 12.5v @ 3amp and is powering a 40w bulb. The shunt is connected to the negative terminal as it does in the van. My bench PSU is rounding the numbers to 1 decimal place and the Ketotek is showing a more accurate 2.98 amp. Not bad for a 100amp shunt resister. I left it running for many hours and the energy reading was also accurate. It doesn’t come with a surface mount box for the meter or the shunt but that’s ok because I am recessing mine. I also have a suitable box for the shunt resistor. I also like the LCD back light which is a single button press on/off. You can set voltage alarm which flashes the backlight so you could set it to 11.9 but I don’t think that would be much use. All in all, my view is that it is accurate and good value for money.

I made some ally U-brackets for the shunt and mounted using the supplied 8mm bolts. I put the display in a plastic box. These were mounted on a plywood base with two input and output connectors (choc block that could take max 16mm in my case). Yes you will need some 16mm (depend on your intended load) cable lengths and some hook up wire, the diagrams are clear. This is accurate, I checked against good quality test gear, spot on. The shunt ran cold, I bought the 100A version, it will never be used above 25A, this is a good factor of safety to aim for. Check the instructions, clear and easy to follow, like the diagram. It remembers the readings too, next time powered up can continue or easy reset. Highly recommended, aimed at somebody who has some experience in wiring and electronics. A remarkable price on Amazon.

The instructions were spot on, the readings are really useful on my boat. the night light is not too bright but is readable during the day too

A current of 0.02A would be displayable but does not get registered hence the Watt meter does tend not to register the standby usage, despite minimal cable length to the shunt. The voltage display is slightly off (~0.1V) , but I need to resite the unit anyway with slightly longer cables, that may bring the display closer to that of my multimeters. I use the unit for monitoring a 24V battery. I assume I could have used the 50A shunt instead for a better resolution in the lower range, especially as I limit the current to 30A anyway. But the battery would happily deliver 70A and I had found myself before upgrading fuses. Generally I would say the unit does what you would expect it to do for this price. The one star deduction is for not registering lower currents at all. Given the price even 5 stars would have possibly been justified.

Was working fine, good readings, very accurate but as soon as it touched 100amps. that was it. Killed it. Has no over amp protection. Make sure u only buy if if u know u won't exceed 99amps

This was bought to replace a similar one that had failed shortly after fitting. As supplied and if connected correctly the meter is great and the accuracy is quite good for the price. Now here it the bit you need to be aware of. The sensing inputs to the meter come from across the shunt and are virtually connected directly to the A/D input of the micro-controller without any real protection over and above a pair of 1k resistors and a parallel connected capacitor. This means that if you accidentally input more than 3.3 volts to either of these lines, r a dose of static, the internal micro-controller gets damaged. As the A/D is only expecting a maximum of 75mv ensure that the shunt is connected securely before applying any system power. Also ensure that you do not discharge any static into the sense lines. All is safe once the shunt is wired in place. For my setup I connected a pair of, reverse parallel, 1N4148,diodes from each input line to ground inside the meter after the 1k resistors. This has so far been successful and I am surprised the designers of this device did not consider this possibility

So long as you know how to wire it well, this works well, and works well within it’s rated current. If you try to put more through it, it will heat up quite a lot but then again it isn’t designed for more than 100a. Display is good. Only thing is that there is no mounting holes on the display so it is difficult to mount on anything but that’s it.

I like the fact that it displays Watt Hours, and that this can easily be reset to zero. I've made up my own solar panel battery charging system, and this device shows me exactly how much energy has been produced each day (or since the last reset). It also displays the current battery voltage, the rate of charge, and the wattage being generated. I can't actually confirm its accuracy but it reads the same as two other meters which I have. The instructions are typical "chinglish", and could be better.

Comes with no cables, and there connection are a bit backwards, read instructions ! Nice back lit display, light can be turned off from front. Got memory that can be reset. Simply works. DO NOTE IT WILL ONLY SHOW LOADS, not any charge of battery.

Didn’t work

funciona correctamente.

Have this working a while now and it’s a very good product

j'ai réussi a intégrer ce petit module de mesure dans un boitier électrique prévu pour 8 modules divisionnaire il est parfait et me permet de contrôler et tester ma première installation solaire ! débutant dans le solaire et ayant mais ayant quand même un diplôme de maintenance électronique toutes les mesures que je fait grâce a ce module vont me permettre de fabriquer ma propre électronique et ensuite d'en mesurer les performances quand le système sera u point seul petit bémol je me suis aperçu les premiers jours qu'il gardait pas la mémoire des kwh et repartait donc a zéro le lendemain matin au lieu de cumuler avec ceux produit la veille puis j'ai fait un test en coupant l’arrivée de courant des panneaux solaire le soir des qu'il ne produisait pratiquement plus rien en les réenclenchant le matin et la oh miracle il gardait en mémoire les kwh produit la vielle je coupe donc les panneaux le soir et je les réenclenche le matin le problème vient de ce que les panneaux se mette en court circuit la nuit voir inverse leur tension ce qui a pour effet de remettre le module a zéro j'ai bien essayer de mettre une diode en série au niveau de la mesure de tension mais ça n'a visiblement aucun effet je pense rajouter une petite batterie de sauvegarde pour résoudre le problème lorsque les panneaux ne produise plus ou bien faire une coupure automatique des panneaux lorsqu'il descendent en dessous de 10 volts