Harbor Freight Mexcharger Question
Prior to going on a recent dry camping trip, I tested my new Mexicowanderer HF Charger. 2/10/55 or whatever it is. If I understand it, for regular charging, it should be set at 10 amps and Start, wh...
Forum Discussion
Hi,
THe battery will stay close to it's starting voltage until a LOT of amperage is pushed into it. If the battery tender is only rated at around 2 amps, it will take some hours for it to raise a battery from 11.8 volts to 12.8 volts (full) and them only a few more hours to raise it from full (12.8) to 14 volts.
Under no load, the battery charger might put out 14 volts, but connect it to a 11.9 volt battery, and it will limit the output.
It is a good thing you did not leave the 2/10 amp charger on the start mode a long time, or the small transformer inside would have melted or a fuse blows. It is only designed to be in the "Start" mode for less than 1 minute at a time, with a considerable rest time to allow the charger to cool off afterwords. Probably printed right on the charger is instructions to use start mode a maximum of 30 seconds, then unplug for 10 minutes (or more).
THe charger is only "Rated" to put out 10 amps all day long. The start mode is only good for a minute or so.
Once the battery is full, say by using the RV charger (should be rated at 45 amps or so) then the 2/10 amp charger will put out about 13.6 volts or 14.2 at the most (hopefully) while the "Start" mode might put out a battery cooking 15 volts or more.
What are the desired battery voltages?
Three stage chargers work like this.
Stage 1 - puts out the maximum charger rated amperage until the battery voltage is about 14.1 volts, then holds 14.1 volts while tapering the amperage until the 14.1 has been held for about 1 hour.
THen stage 2 it will reduce the voltage to 13.8 and still run a lot of amperage into the battery, at a rate so fast the battery will feel warmer than the air around it. Yes some water will be lost at this high voltage.
Then stage 3, it will reduce to 13.2 to 13.4 volts, and hold this voltage until the charger is unplugged.
Some very smart chargers will count 30 days, then go back to stage 1 for a hour or so each month. This is what the Trace Pro Chargers do.
So best thing? Let the RV charger do it's thing. If you are not getting good results from that charger, replace it with a good converter/charger.
One problem you might have is if you have a decent charger, and put on your 2/10 amp charger to "Help" it, the charger/converter will see the 14 volts, and quickly shift from the stage 1 bulk charge mode to stage 2 or even stage 3, and not put out very many amps at all. This will slow the overall charge rate for the battery, by not letting the 45 amp RV mounted charger do it's thing.
Fred.
THe battery will stay close to it's starting voltage until a LOT of amperage is pushed into it. If the battery tender is only rated at around 2 amps, it will take some hours for it to raise a battery from 11.8 volts to 12.8 volts (full) and them only a few more hours to raise it from full (12.8) to 14 volts.
Under no load, the battery charger might put out 14 volts, but connect it to a 11.9 volt battery, and it will limit the output.
It is a good thing you did not leave the 2/10 amp charger on the start mode a long time, or the small transformer inside would have melted or a fuse blows. It is only designed to be in the "Start" mode for less than 1 minute at a time, with a considerable rest time to allow the charger to cool off afterwords. Probably printed right on the charger is instructions to use start mode a maximum of 30 seconds, then unplug for 10 minutes (or more).
THe charger is only "Rated" to put out 10 amps all day long. The start mode is only good for a minute or so.
Once the battery is full, say by using the RV charger (should be rated at 45 amps or so) then the 2/10 amp charger will put out about 13.6 volts or 14.2 at the most (hopefully) while the "Start" mode might put out a battery cooking 15 volts or more.
What are the desired battery voltages?
Three stage chargers work like this.
Stage 1 - puts out the maximum charger rated amperage until the battery voltage is about 14.1 volts, then holds 14.1 volts while tapering the amperage until the 14.1 has been held for about 1 hour.
THen stage 2 it will reduce the voltage to 13.8 and still run a lot of amperage into the battery, at a rate so fast the battery will feel warmer than the air around it. Yes some water will be lost at this high voltage.
Then stage 3, it will reduce to 13.2 to 13.4 volts, and hold this voltage until the charger is unplugged.
Some very smart chargers will count 30 days, then go back to stage 1 for a hour or so each month. This is what the Trace Pro Chargers do.
So best thing? Let the RV charger do it's thing. If you are not getting good results from that charger, replace it with a good converter/charger.
One problem you might have is if you have a decent charger, and put on your 2/10 amp charger to "Help" it, the charger/converter will see the 14 volts, and quickly shift from the stage 1 bulk charge mode to stage 2 or even stage 3, and not put out very many amps at all. This will slow the overall charge rate for the battery, by not letting the 45 amp RV mounted charger do it's thing.
Fred.
