Since my recent upgrade to the larger group 65 Odyssey battery, after installation of Sasquatch adaptation tray, something keeps on nagging me, and I would like to clear it once and for all.


As I was searching for the battery locally I spent some time at the local distributor and it came out during one of those conversations, which was unknown to me prior, and needles to say very surprising, that hose batteries CAN NOT be charged with your old school 10-12 A battery chargers, and absolutely NOT with and 2A tricklers as not only they will damage the battery but also will void the warranty. In Odyssey case, they have special 20A chargers meant specifically for their AMG batteries, and they insist that this is the only way to charge batteries if needed.


Now, my question is, how well will the OEM alternator work to keep it charged? Is there a necessity to upgrade the existing alternator to a stronger unit? If so, is there something on the market that will work in the space of CRD? I am told upon a quick inspection that my alternator needs new pulley and new bearings, so I will be taking this out soon to be rebuild but I also ight use the time to replace the unit for something more proper. Any ideas?

How often do you make those overnight charges? Regularly or just every now and then when you think the battery down after testing?

Different charging methods are needed to properly charge AGM batteries,anyone who says otherwise is misinformed.

Your alternator is a high amp charging device and AGM's do like higher amp charges for there initial charge from a deep cycle discharge and you can ruin a AGM battery by slow charging it when in a deep discharge state(this mainly applies to marine applications or race cars).To maintain and "top off" charging low amps is okay for AGM's but you do need a approved AGM charger which supplies slightly higher voltage then your standard wet cell battery chargers.Don't have a AGM battery charger? Optima has a chart showing how to charge a AGM battery with a wet cell battery charger,you will need a regular wet cell automotive battery though.


1 thing is you will need to charge the battery every few months as your alternator is not designed to fully charge a 850+cca battery,keep that in mind and prepare.You can buy some real nice AGM chargers that will not break the bank and yes Odyssey even offers some low priced chargers for there batteries and will work for the group 65 as long as it's not in a deep discharge state which is under 10-11 volts.

Is this right, that the original battery in KJ CRD was AGM?? I would not know that as I bought my CRD used, with a regular wet battery installed by the dealer just as I was buying the vehicle. First of all, he installed that battery because he had difficult time with starting it when cold and assumed the battery was to blame. Second, as there is nothing stamped on that battery I don't even know what is/was the CCA on it, but what I know is that it was definitely underperforming right from the start especially in cold weather. NOW, to add to the problem, as was suggested in previous post, I do rather short commuting, which I am aware of, and try to compensate with longer rides on weekends. I don't know however if such a compensation will work without an additional charging. Just trying to cover that gray area before I run this brand new group 65 Odyssey battery to the ground.

This is the sellers pitch trying to sell you a "AGM" battery charger !!!!

The battery I got in my Jeep is the Odyssey 34M-PC1500ST TROLLING Thunder Marine Dual Purpose Battery and it's a deep cycle battery putting out 880CCA . It's was taken out of an industrial forklift as the pack of 4 batteries where consider bad. I found that this one wasn't that bad. and it still going strong after 5 years.

For fast industrial charge you will need a specialized charger to charge this kind of battery daily, but for use in a passenger vehicule a little smart charger at low amp do just fine.

And yes you can use a deep cycle battery in a car if the cranking amp is there but they usually take longer to charge and it can be a problem if you do short commute only. And you don't need a "deep cycle" battery charger , this is another mith as well !

I'm planning on putting a 3amp battery tender in my project crd. With a cord adapter joining it with my block heater. Both on at night when needed. Or get a Schumacher electronic charger that's what we use on our AGM Odyssey's at work. Even duralast at autozone http://m.autozone.com/test-scan-and-specialty-tools/battery-charger/duralast-10-6-2-amp-charger-maintainer/837570_0_0/ ten amp is plenty. It's high voltage that kills agm batteries. Makes them gas too much and dry out. My Schumacher charges at regulated voltage and doesn't go over something like 14 or 14.5 bolts. Guess what our alternator Max is?

I'm planning on putting a 3amp battery tender in my project crd. With a cord adapter joining it with my block heater. Both on at night when needed. Or get a Schumacher electronic charger that's what we use on our AGM Odyssey's at work. Even duralast at autozone http://m.autozone.com/test-scan-and-specialty-tools/battery-charger/duralast-10-6-2-amp-charger-maintainer/837570_0_0/ ten amp is plenty. It's high voltage that kills agm batteries. Makes them gas too much and dry out. My Schumacher charges at regulated voltage and doesn't go over something like 14 or 14.5 bolts. Guess what our alternator Max is?

If your in a cold climate look at the at the temperature rating of your charger !

that was my idea when I bought the .75 amp noco charger but in the manual they say not to use below -20 celcius