Recently I purchased a Noco genius charger to replace a Schumacher battery maintainer which had stopped working. I used the Noco a couple times before it too stopped working. I run these from under the hood. I use these 8-9 days after my last outing for about 12-24 hours, when they read fully charged. And then I’m usually driving the car a few days after. (drive little in winter, and little under covid) This is a 2012 Prius V. Advice from Toyoto was that I should take a trip and then put on a maintainer and keep it there, which no doubt solves the problem, but seems unnecessary. And it doesn’t answer the question as to why my devices stop working. I returned the noco because it cost more and time for return was running out. I still have the Schumacher which worked for about 16 months. I tried these on the battery itself and same non-results--and of course in all these situations the car itself does start which it will usually do up to 14 days. It’s a mystery to me why the maintainers stop working (zero abuse to either & and used in my garage). Anything to clear up this confusion is appreciated.
I like Battery Tender. I would be sure to disconnect it before running the car as the hybrid sytem charging algorithm might be fighting your battery maintaner if it was on.
How exactly did they "stop working" ? It is possible that your battery is now beyond it's useful life. "Smart" chargers often won't attempt to charge a battery if it's "quick test" indicates that the battery might be bad. My Schumacher will sometimes indicate a full charge or a fault if I connect it to the wall first. Try connecting to the battery first and then to the wall. And what you have been told is correct, it is WAY better to connect your smart maintainer any time that you think the vehicle will go unused for more than a few days. Two weeks is too long for optimum battery health.
We use a CTEK 7002 along with an LED battery condition 'comfort indicator' (tell-tale) on each battery in the 'fleet' and find it and they work well to smart charge and monitor.
It sounds like the chargers/maintainers you are using are being damaged from the supply side, or wall outlet. Not knowing much about power in your area of NY I would try to first have the household wiring checked from the outlet to the electric panel. If it is actual service issue from the electric company then a surge protector may help take care of future failures, or better yet a back up battery UPS, which also cleans up the waveform. (The UPS idea may be overkill, hopefully). Pardon the messy garage, but these are just three that are kept with automatic charger/maintainer 24/7/365. moto g(7) power ? View attachment 195089
