How Much Charge Current When Battery Full?

[twistedtree]

Originally Posted by goboatingnow

all smart ones do. Otherwise they don't know when to terminate absorption.

dave

Which ones? I've been looking for one.

[ShaunJ]

Originally Posted by Maine Sail

I know of at least two manufacturers of smart marine battery chargers that do not do this and who do not operate in-line with the "all smart ones do" statement.

Would you care to share your knowledge?

[Nicholson58]

I have a pretty old Xantrex 2KW unit that wants to know the amp hours each bank. As I read & learn more I go back to the interface panel and tweak the parameters. Lots of chargers are timer operated and not very smart.

[Maine Sail]

Originally Posted by ShaunJ

Would you care to share your knowledge?

The Sterling Pro-Charge Ultra and ProMariner ProNautic-P are but two examples of smart chargers that do not use current for the transition to float. They know the current, and can display it, but they don't use it to switch from absorption to float. This info came directly from the designer....

In order to use current you'd need a shunt on the DC load side of the system and you'd need to program the banks capacity into the charger. Cruising Equipment/Heart Interface, later became Xantrex, used to make these but they were often quite glitchy. I have a number of customers with half the system working and the other half they are scouring eBay for parts to hopefully make it work again..

I don't know anyone making anything like that today but if anyone does I'd like to hear about it..

[ShaunJ]

Originally Posted by Nicholson58

You really really really need to read about Trojan (and other) battery charging. 14.8 is the magic number. Your batteries are nearly discharged according to Bob and Trojan. The short of it is the charger people don't talk to the battery makers. The added problem can be that the wire gauge is too small so the charger voltage is measured at the charger, not at the battery where the voltage will be less due to drop in the wires.

https://handybobsolar.wordpress.com/


Bob's blog is very long. It took me most of an evening to go through it. He hasn't much nice to say about the usual folks who sell us this stuff.

Nice link, thanks. I took me 2 night to go thru it but learned a bit. Has anyone else read thru this blog? What do you think?

[sailinglegend]

........... https://handybobsolar.wordpress.com/
I took me 2 night to go thru it but learned a bit. Has anyone else read thru this blog? What do you think?

I'm surprised you manage to get through it!

He's trying to do a good job, but doesn't have the skills to execute it. Sorry to be so critical but I have never seen paragraphs so long whith so many different ideas in the same paragraph. It needs severely editing and headlining to be of use to any casual reader.

I also cannot stand posters who have such strong views about subjects that they have not experienced themselves or researched properly before they make such statements. I refer to his agreement with a Mr Sterling on his ideas about AGMs.

They both maintain that with a charge voltage of only 14.2-14.4 volts they can't charge as quickly as open lead acid batteries that can go up to 14.8 volts. They ignore the "facts" that AGMs have a much lower internal resistance and their “efficiency” at accepting charge is much better. Wet cells may be only 75% efficient which means that 125 Ah or more must be put in to actually raise the capacity of a battery by 100Ah. AGMs may be 98% efficient so only 102 Ah need to be put in. That means faster charging.


"Ignorance isn't what you don't know - but what you think you know that is incorrect."