battery charger

[MF243RedTop]

I've got one similar to this ...you just can't kill it..
I would look through FB marketplace or eBay before buying one of fancy worthless new chargers ...
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Sticking to my guns here ...
New tech out ..ole tech..hell yeah..

 

[John_Mc]

Sticking to my guns here ...
New tech out ..ole tech..hell yeah..

Those old tech chargers are OK if you have a dead or low battery you want to bring up to full charge (unless the battery is sulfated, in which case the charge won't hold for long.) However, too many of those old tech chargers will cook a battery if left on long term. When I'm looking for a battery maintainer for a piece of equipment that is used only occasionally, or might sit idle for a season, I want one that I can set and forget, not one that I'll come back to and find it has boiled off electrolyte in the battery.

 

[bdhsfz6]

Years ago, I used to use a trickle charger on a timer for my seldom used batteries. I had to adjust it seasonally for temperature variations though. Worked fine until a diode failed and it completely discharged one of the batteries.

I eventually moved into the modern age and began using maintainers. Just set and forget with much less hassle and they also work with lithium batteries.

Use what works for you though. YMMV.

 

[John_Mc]

For some reason I don't understand, neither brand can be relied on to charge a completely discharged battery. To charge a totally flat battery I first hook it up to an old transformer type charger for an hour, then the BatteryMINDer or Noco can take over from there.

Part of that reason is to protect the charger from shorting out if someone plugs it in and the leads manage to touch each other. By not activating until it finds some minimum voltage, the charger is protected from that.

Older smart chargers used to have a floor voltage of something like 10 or 10.5 V. A Flooded lead-acid battery should be around 12.6 or 12.7 volts when at rest and fully charged. A starting battery which reads around 11.8-12 volts when at rest or less than 10.5 under load is considered "discharged" (deep cycle batteries are a bit different). A dead cell in a battery can often cause the battery to read around 10.5 volts at rest. Attempting to charge this battery can end up with that one cell still dead, and the other cells overcharged as the charger keeps trying to bring the battery up to full charge. If the charger continues for force this, it can be dangerous, as the cells will off-gas hydrogen if they are overcharged. The 10 - 10.5 volt cutoff was intended to indicate that "something is wrong here. You need to further test the battery before forcing a charge."

In more recent years, the manufacturers of smart chargers figured out how to test for a dead cell (beyond just measuring resting voltage). So the battery is tested periodically during the cycle. If it fails, the charger shuts off. (Some of them also will time out and shut off after some period of time, if the battery has failed to reach a full charge.) This testing ability allows them to set a much lower minimum voltage threshhold (some use as low as 1 volt) while still protecting the charger from inadvertent shorting of the leads. Some smart chargers also have a "force mode", which basically tells the charger "act like a dumb charger for a bit, then try to switch to smart mode and continue charging if the battery continues to pass smart chargers testing.

The idea of connecting a dead battery in parallel to another battery to bring it up enough for the smart charger to recognize it is sort of like a poor man's "force mode". You are using the the good battery to either bring the dead batty up, or to temporarily provide some voltage for the smart charger to sense. I'd recommend removing the battery from the vehicle when doing this and monitoring the batteries and cables for overheating. Discontinue if the battery gets too warm.

 

[John_Mc]

I eventually moved into the modern age and began using maintainers. Just set and forget with much less hassle and they also work with lithium batteries.

We have an all electric car which uses lithium batteries, and a whole pile of lithium-powered smaller devices. I've never tried a lithium battery as a starting battery in a vehicle.

Do you have experience with that? Were you able to just swap it in with no changes to the vehicle's charging system? I almost went with a lithium battery in my UTV (uses a small motorcycle sized battery). I decided to go with an AGM battery instead, when I read about some concerns with cold weather charging being a problem. (The electric car has a heating system for the batteries to bring them to the appropriate temperature when charging.) Since this is my snow plowing vehicle for all but the biggest storms (where the tractor and snow blower are called into duty), I did not want to chance it.

If you or anyone has experience with using lithium as a starting battery in cold climates, I'd love to her about how it is working out and any special precautions you need to take.

 

[bdhsfz6]

We have an all electric car which uses lithium batteries, and a whole pile of lithium-powered smaller devices. I've never tried a lithium battery as a starting battery in a vehicle.

I have this one:

https://www.amazon.com/dp/B0CRRKRJ2S?tag=bg1-264920-20&th=1

I like it because it holds a charge when not used for a period of time. All the lead acid booster packs I've had in the past seemed to loose their charge when stored, and are next to useless when I need them most.

 

[John_Mc]

I have this one:

https://www.amazon.com/dp/B0CRRKRJ2S?tag=bg1-264920-20&th=1

I like it because it holds a charge when not used for a period of time. All the lead acid booster packs I've had in the past seemed to loose their charge when stored, and are next to useless when I need them most.

Thanks. I do need to add a booster to my collection one of these days.

However, I was actually asking about using a lithium battery as the actual starter battery mounted in the vehicle. I have some friends who use them in their motorcycles, but those only tend to get ridden in the warmer half of the year here in Vermont, so winter starting and recharging isn't much of a concern in that application. My UTV (a Honda Pioneer 520) gets used off and on year round. Our passenger vehicles all get used even when it's -20˚F.