Gel Battery Charging
- Thread starter Sea Biscuit
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NO to automotive charger.....
unless (highly unlikely) it is set up to handle gel cells. Regular car batteries are fairly tolerant to high charging voltages, but that is the absolute fastest way to kill a gel cell. The charging voltage MUST be carefully controlled, or you end up with an expensive and heavy piece of junk that has a recycle value of about 20 cents per pound. If you already have the gel cells, you should invest in a top-quality charger, such as the Xantrex TrueCharge or XC. Also, you will most likely need a new alternator and/or regulator, as most of those are not equipped to handle gel cells If you haven't bought the gel cells yet, you might want to reconsider, depending on your boat and usage. For most sailors, they are about as useful or necessary as a stainless-steel anchor.
Cheers, Bob s/v X SAIL R 8
unless (highly unlikely) it is set up to handle gel cells. Regular car batteries are fairly tolerant to high charging voltages, but that is the absolute fastest way to kill a gel cell. The charging voltage MUST be carefully controlled, or you end up with an expensive and heavy piece of junk that has a recycle value of about 20 cents per pound. If you already have the gel cells, you should invest in a top-quality charger, such as the Xantrex TrueCharge or XC. Also, you will most likely need a new alternator and/or regulator, as most of those are not equipped to handle gel cells If you haven't bought the gel cells yet, you might want to reconsider, depending on your boat and usage. For most sailors, they are about as useful or necessary as a stainless-steel anchor.
Cheers, Bob s/v X SAIL R 8Proper charge and longer life.
If you want to get the proper charge and a longer life, you really want a smart charger. Now that you have spent the money on the batteries, you just need to spend some money on the proper charger. Depending on the size of your banks, you want to get a high quality charger like the Xantrex TrueCharger 20+, 40+ or one of the newer units (Xantrex xc) that can charge multiple battery chemistries at the same time.
If you want to get the proper charge and a longer life, you really want a smart charger. Now that you have spent the money on the batteries, you just need to spend some money on the proper charger. Depending on the size of your banks, you want to get a high quality charger like the Xantrex TrueCharger 20+, 40+ or one of the newer units (Xantrex xc) that can charge multiple battery chemistries at the same time.
But, an AGM...
supposedly has charging profiles very much inline with flooded cell batteries. Smart chargers are certainly the way to go, but I have read that you can combine AGM "start bank" with your flooded Trojans on the "house bank" all off one smart charger like the True Charge 20. Other comments???
supposedly has charging profiles very much inline with flooded cell batteries. Smart chargers are certainly the way to go, but I have read that you can combine AGM "start bank" with your flooded Trojans on the "house bank" all off one smart charger like the True Charge 20. Other comments???
AGM not the same as gel cell
AGM's are touted as the next generation: All the advantages of both gels and flooded. There is some truth to that, but all batteries die eventually, and eventually is further in the future the more you control the charging cycles. I highly recommend the Xantrex products, as I have staked my life on them in extreme situations on more than one occasion (and obviously haven't regretted it....yet). A top-end battery charger will allow you to realize the advantages of gel or AGM batteries. That being said, the cost of high end batteries, amortized over the extended life of those batteries, is about the same as the cheap, shorter-lived batteries. Over a prolonged period (say 10 years), you will have spent roughly the same amount of money on batteries no matter which kind you buy. In the case of the AGMs, you will have had half as many instances of potentially inconvenient battery failures during that time.
AGM's are touted as the next generation: All the advantages of both gels and flooded. There is some truth to that, but all batteries die eventually, and eventually is further in the future the more you control the charging cycles. I highly recommend the Xantrex products, as I have staked my life on them in extreme situations on more than one occasion (and obviously haven't regretted it....yet). A top-end battery charger will allow you to realize the advantages of gel or AGM batteries. That being said, the cost of high end batteries, amortized over the extended life of those batteries, is about the same as the cheap, shorter-lived batteries. Over a prolonged period (say 10 years), you will have spent roughly the same amount of money on batteries no matter which kind you buy. In the case of the AGMs, you will have had half as many instances of potentially inconvenient battery failures during that time.
Mike, maybe!
Mike: I agree with you that you are going to get many more years out of Gel/AGM batteries than most cheap batteries (if they are on a proper charger). I also agree that you are going to have several more years without worrying about replacing and maintenance. What I am not sure about the overall cost. I just purchase 2 G31 Gel's for $170 each ($340 total) for about 210 amps. These batteries have more usable amps than flooded and should last for 10 years. If I am paying $65-85 for an equivalent flooded battery and I only get 2-3 years of life, they are going to be more expensive over the life of the system. This is taking into account that I have properly maintained the flooded batteries (which I personally may or may not have done over the period of 10 years). My take on Gel/AGM's is that they are generally a good investment if you plan on keeping a boat. Get the proper charging system and they will serve you well.
Mike: I agree with you that you are going to get many more years out of Gel/AGM batteries than most cheap batteries (if they are on a proper charger). I also agree that you are going to have several more years without worrying about replacing and maintenance. What I am not sure about the overall cost. I just purchase 2 G31 Gel's for $170 each ($340 total) for about 210 amps. These batteries have more usable amps than flooded and should last for 10 years. If I am paying $65-85 for an equivalent flooded battery and I only get 2-3 years of life, they are going to be more expensive over the life of the system. This is taking into account that I have properly maintained the flooded batteries (which I personally may or may not have done over the period of 10 years). My take on Gel/AGM's is that they are generally a good investment if you plan on keeping a boat. Get the proper charging system and they will serve you well.
Mixing battery chemistries is not recommended....
and the Xantrex TrueCharge chargers only have one output, so you can't really mix types. It's true that AGM and flooded cells are very similar during bulk, acceptance and float phases, AGM should never be hit with an equalizing charge, but this is necessary for flooded cells. The more expensive Xantrex (I think it's the XC) chargers DO have multiple outputs, so you can mix battery types. Mixing battery types on one charger also isn't recommended because they have different charging rates - you may find that one battery is 'hogging' the bulk charge and the other is getting starved in the process... not a good situation to be in. I'm still not convinced that AGM are necessary or advantageous for weekend-type sailors. Batteries that aren't cycled deeply or often will last a LONG time. I have a flooded 8D battery that just celebrated its 11th birthday. I'm rooting for it to last, because I don't really look forward to having to hoist it out of the cabin. After all, most batteries fail either because plate material gets knocked off and falls to the bottom of the cell and eventually shorts out, or sulfation builds up to the point that there isn't enough plate material exposed to the acid to hold a decent charge. Proper care and few deep discharge cycles will prevent these failures for a long time. Cheers, Bob s/v X SAIL R 8
and the Xantrex TrueCharge chargers only have one output, so you can't really mix types. It's true that AGM and flooded cells are very similar during bulk, acceptance and float phases, AGM should never be hit with an equalizing charge, but this is necessary for flooded cells. The more expensive Xantrex (I think it's the XC) chargers DO have multiple outputs, so you can mix battery types. Mixing battery types on one charger also isn't recommended because they have different charging rates - you may find that one battery is 'hogging' the bulk charge and the other is getting starved in the process... not a good situation to be in. I'm still not convinced that AGM are necessary or advantageous for weekend-type sailors. Batteries that aren't cycled deeply or often will last a LONG time. I have a flooded 8D battery that just celebrated its 11th birthday. I'm rooting for it to last, because I don't really look forward to having to hoist it out of the cabin.
After all, most batteries fail either because plate material gets knocked off and falls to the bottom of the cell and eventually shorts out, or sulfation builds up to the point that there isn't enough plate material exposed to the acid to hold a decent charge. Proper care and few deep discharge cycles will prevent these failures for a long time. Cheers, Bob s/v X SAIL R 8Your mileage may vary
Being relatively new technology, AGM costs may have improved enough to tilt the equation in favor of them, investment wise. Most applications in which I install AGM are where I expect serious discharge abuse and/or where replacement is a major logistical issue (i.e., remote installations and anticipated long periods during which power is needed but a charging source may not be available). I've got flooded cells in my weekender because I am cheap and the only thing that draws power when I'm away from the dock is the stereo.
Being relatively new technology, AGM costs may have improved enough to tilt the equation in favor of them, investment wise. Most applications in which I install AGM are where I expect serious discharge abuse and/or where replacement is a major logistical issue (i.e., remote installations and anticipated long periods during which power is needed but a charging source may not be available). I've got flooded cells in my weekender because I am cheap and the only thing that draws power when I'm away from the dock is the stereo.
Not hoggin' the charge with the XC
Bob: The XC charger actually cycles through the banks (up to 3) and changes the charging algorithm to match whatever you program into the charger. The only problem with this is your alternator. There are some of the charging systems that will allow the alternator to also charge different battery chemistry's.
Bob: The XC charger actually cycles through the banks (up to 3) and changes the charging algorithm to match whatever you program into the charger. The only problem with this is your alternator. There are some of the charging systems that will allow the alternator to also charge different battery chemistry's.
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