Old Crow
Searching....
I have solar maintainers on the starting batteries of several of my vehicles. I installed the first one on my mother-in-law's car in January 2018 as a result of this Frozen Battery thread. The short version of that is the battery froze because it wasn't being kept charged by the rarely-driven car. The thread discusses how the battery was restored to service.
After the battery was charged back up, I put the solar maintainer on and that worked well. I was surprised to see a 5-watt panel could do that and, in fact, could do it from inside the car (on the dashboard) with the car parked pointing north. I checked it many times and with the panel in place the little Civic's battery was always right around 13 volts and it always started very easily. That one is the 5-watt version of the Battery Tender Solar Battery Charger. I had selected it because of its built-in controller, reasonable price point (for both panel and controller) and my experience with Battery Tender-brand wired maintainers.
It went so well that when my brother told me he kept finding one of his truck's batteries too low for starting, I bought another and had it delivered to his address. It was the same situation--- a vehicle only used occasionally and no AC power anywhere close. That too has worked well (since April 2018).
When we sold Mom's Civic, I moved its solar maintainer to my lawn tractor. I've noticed I'd find voltage sitting at 12.9 to 13 volts when i went out to mow. But one time I found it sitting at 12.3 volts... but that was because my CRS had flared up and I had forgotten to plug in the maintainer after using the tractor the previous time.
I recently went out and found the battery at 12.6....and the maintainer was connected. Ugh. That's an OK resting voltage but not with a maintainer running (I'm thinking). I unplugged the panel from the wire loom and checked with a voltmeter. Zero volts. Rats.
Given the relatively short lifespan, I didn't want to just replace it like for like. I had paid about $60 for it and a direct replacement is now about $70 on Amazon. But I found I could get an 18-watt one for $75 and its built-in controller is an MPPT one. So I ordered that one.
I installed the 18-watt one last week and once again tested the old 5-watt one at the connection leads-- still nada.
Later that day, I started this post with the title "My solar maintainer died". But when I went to find a web link to it I saw a review say the maintainer must see at least 3 volts to work. Did I just screw up?
Long story short-- yes. I subsequently contacted tech support and learned that's indeed the case. It will show no voltage as that's part of the reverse polarity and lead-shorting protection. (This one has the controller built in so I wasn't measuring raw panel voltage, I was measuring output of the controller.)
I then ran a different test of the 5-watt maintainer. After opening the hood I measured voltage at the battery and allowed it to settle from opening the door and then put on the maintainer. Current is so low that it takes time to see battery voltage rise but it did indeed rise. The maintainer isn't bad after all.
So what happened? All I can think is I must have found that 12.6 volts figure -- the one that caused me to suspect it--- at a time when 12.6 was normal and I just didn't realize it. I'm used to looking at powered-all-the-time maintainers and seeing a voltage above 13 volts. But solar maintainers drop power daily (when the sun goes down) and the battery will settle to its resting voltage (in the mid-12s) overnight. And the maintainer doesn't just instantly go back up to its peak when the sun comes up.
.
After the battery was charged back up, I put the solar maintainer on and that worked well. I was surprised to see a 5-watt panel could do that and, in fact, could do it from inside the car (on the dashboard) with the car parked pointing north. I checked it many times and with the panel in place the little Civic's battery was always right around 13 volts and it always started very easily. That one is the 5-watt version of the Battery Tender Solar Battery Charger. I had selected it because of its built-in controller, reasonable price point (for both panel and controller) and my experience with Battery Tender-brand wired maintainers.
It went so well that when my brother told me he kept finding one of his truck's batteries too low for starting, I bought another and had it delivered to his address. It was the same situation--- a vehicle only used occasionally and no AC power anywhere close. That too has worked well (since April 2018).
When we sold Mom's Civic, I moved its solar maintainer to my lawn tractor. I've noticed I'd find voltage sitting at 12.9 to 13 volts when i went out to mow. But one time I found it sitting at 12.3 volts... but that was because my CRS had flared up and I had forgotten to plug in the maintainer after using the tractor the previous time.
I recently went out and found the battery at 12.6....and the maintainer was connected. Ugh. That's an OK resting voltage but not with a maintainer running (I'm thinking). I unplugged the panel from the wire loom and checked with a voltmeter. Zero volts. Rats.
Given the relatively short lifespan, I didn't want to just replace it like for like. I had paid about $60 for it and a direct replacement is now about $70 on Amazon. But I found I could get an 18-watt one for $75 and its built-in controller is an MPPT one. So I ordered that one.
I installed the 18-watt one last week and once again tested the old 5-watt one at the connection leads-- still nada.
Later that day, I started this post with the title "My solar maintainer died". But when I went to find a web link to it I saw a review say the maintainer must see at least 3 volts to work. Did I just screw up?
Long story short-- yes. I subsequently contacted tech support and learned that's indeed the case. It will show no voltage as that's part of the reverse polarity and lead-shorting protection. (This one has the controller built in so I wasn't measuring raw panel voltage, I was measuring output of the controller.)
I then ran a different test of the 5-watt maintainer. After opening the hood I measured voltage at the battery and allowed it to settle from opening the door and then put on the maintainer. Current is so low that it takes time to see battery voltage rise but it did indeed rise. The maintainer isn't bad after all.
So what happened? All I can think is I must have found that 12.6 volts figure -- the one that caused me to suspect it--- at a time when 12.6 was normal and I just didn't realize it. I'm used to looking at powered-all-the-time maintainers and seeing a voltage above 13 volts. But solar maintainers drop power daily (when the sun goes down) and the battery will settle to its resting voltage (in the mid-12s) overnight. And the maintainer doesn't just instantly go back up to its peak when the sun comes up.
.
