Do AGM's charge quicker?

Ed, thanks for the link to the article. I think this is the most comprehensive and through test I have seen on charging AGM batteries. Lots of good info. Thanks again.

Ken

"then I should just charge to 90% when dry camping. Anything beyond 90% will take up to 15 hours to achieve 100% that's a waste."

Another reason for solar! No waste, noise etc. Just full batteries.

Ed_Gee wrote:

SFVdave wrote:
Looking to cut generator time. Have solar but sometimes have little to no sun when dry camping. Read AGM's charge up to 5X faster than flooded. How can that be, converter charger only puts out so much?

Word in the industry is that AGM batteries can be charged UP TO 5 times faster than flooded batteries. I did a little digging and if you can stomach the rather lengthy read, I believe all your questions will be answered here in the outstanding test. Fast Charging AGM batteries. Worse case, just scroll to the bottom for the resulting graph.

Good link, thanks! (That guy could have saved himself a lot of work if he had seen my "ugly graph" on here :)

SFVdave wrote:
Anything beyond 90% will take up to 15 hours to achieve 100% that's a waste.

If you want true 100% charging, Li batteries can do that. But, there's the cost.

I think it may be best to buy Trojan SCS 200 group 27 which has 115 amp hours. That will give me an extra 30 amp hours with the two batteries then I should just charge to 90% when dry camping. Anything beyond 90% will take up to 15 hours to achieve 100% that's a waste.

You're right, charger only puts out so much.

SFVdave wrote:
Looking to cut generator time. Have solar but sometimes have little to no sun when dry camping. Read AGM's charge up to 5X faster than flooded. How can that be, converter charger only puts out so much?

Word in the industry is that AGM batteries can be charged UP TO 5 times faster than flooded batteries. I did a little digging and if you can stomach the rather lengthy read, I believe all your questions will be answered here in the outstanding test. Fast Charging AGM batteries. Worse case, just scroll to the bottom for the resulting graph.

Does that mean when I am down 70 amp hours on my batteries and my converter charger is putting out 30 amps out of the 55 A available, it will put out closer to the 55 Amps?

It only helps if you upgrade the charger to suit. And it still takes many hours to complete the absorption phase.

But it’s true you can do bulk faster with AGM, which is one of the reasons I prefer them.

If you don't change your converter, you probably won't notice much difference but maybe a little.

An AGM has a lower internal resistance and will draw a higher charging current for longer than conventional lead acid.

That makes little difference if your converter is running at MAX now.
It may charge at MAX a bit longer but that probably won't get you much.

While they CAN charge a lot faster, it might not be a good idea to push them hard enough to get 5X the speed. And I don't think any charger commonly available on the consumer market will charge with a high enough voltage to make that happen.

AGMs have several small advantages that I think are worth the extra money. Many people don't. It's your call.