Difference between charger models

A question for the more electrical-minded out there.

My dad's on-board charger died on him - there is a possibility it remained plugged in when he pulled the boat out of the garage this spring, but we get no charging lights when we plug it in now.

I did a search to try and find the same exact model so we don't have to drill any new holes.  He has a Guest Charge PRO 2623 3-bank charger.  Couldn't find any of those, but I did find a 2631 model.

The only difference I can see between the two is the 2623 is 10-5-10 amps, and the 2631 is 10-10-10 amps.

He has an 18' Lund Tyee, 130 HP Honda 4-stroke, with a 24V trolling system using 2 batteries, plus his starter battery.

Does the extra amperage going to the starter battery make any difference?

Thanks.

Apparently I need to learn some more.

They (dad and brother-in-law) got the Noco installed and plugged in Friday night.  Saturday, we had minimal juice that ran out quickly.  Got back to camp and started troubleshooting.  Found out that brand new Nocos start out in "standby mode" when you plug them in the first time, and you have to select the charging mode based on type of battery they are hooked up to.  THEN it will remember the settings after that.

I have the trolling batteries charging now, but the starter battery (at least I'm assuming it's the starter battery, will have to check to see which one it is connected to) will not come off standby mode.  Trouble-shooting says likely the battery is too low to detect (which I highly doubt because the starter battery was running all electronics and pumps and starting boat just fine all day), or could be a blown inline fuse (which I don't know if they put one on the starter battery when they spliced into it).

Any other Noco owners have an idea?  It probably doesn't matter during the summer because the motor will charge the starter battery, but dad will want it working for trickle/maintenance over the winter.

EDIT - got a reply from brother-in-law who hooked them up.  A trolling battery and the starter are charging.  One of the trollers is the one that won't come off standby.  Need to check for blown fuse, or it could be too low to be detected and we need to jump it a bit.

Well, all moot now.  They bought a Noco Genius 3-bank.

I learned a lot about batteries/chargers, anyways.....thanks.

Minn kota precision on board charger are easily the best. Most people I know switch to them if your worried about drilling new holes it's real easy. The charger is a 2 bank with 10 amps per bank the charger will compensate for voltage loss from power source and you can change each bank from agm gel or lead acid and it also has a setting to equalize lead acid battery s so they last longer. Have yet to have a problem I use all agm battery and I don't charge the starting battery as the the motor will recharge it while driving.

Newer chargers often times have a switch or mode for either Sealed lead acid or the newer AGM batteries.  At least my NOCO charger does.  My assumption is that the service rep is suggesting the "A" model will work with AGM batteries.  I use all AGM in my both for both starter and house.  

Was also told to only have all AGM or all SLA batteries and do not mix if you have a 2+ bank charger.

Yeah, I would ask for clarification, since lead acid battery chemistry is over 100 years old.

My mother spent some time with Guest customer service, asking about the 2631 - they said she needs to buy a model that ends with an A "to make sure it will charge the newer batteries."

Since the charger that was in the boat when he bought it (the 2623) has worked for over 10 years until now charging "newer" batteries, should I tell her to call them back and have them explain?

I'm thinking they're just trying to sell one of their own chargers, rather than have her buy one she found cheaper elsewhere.

The standard charge rate for industrial lead acid batteries is 17% of capacity.  Most of the lead-acid batteries installed on boats are between 85AH and 115AH, which means charges rates up to 20A or so are appropriate.

There is no lifetime degradation at these charge rates.

The alternator on your big motor puts out considerably more than this when it is charging your starting battery, at least initially.

So to answer your question, no difference at all.

The difference Nemab-man sees is likely due to different finish voltages, not different charge rates.

I have a Guest Pro myself in my Ranger which is a 5-5-5 amp version,  and I also have three batteries with two being rigged for my 24 volt trolling motor, I can check the model when I get home , don't have any issues charging with the 15 amp 3 bank, but my boat is always plugged  in between trips in my garage and not heavily on the tolling motor but run two graphs , no issues with mine .