Older outboards and new AGM batteries not compatible!!

So needed new starting battery for my 1992 Johnson 150hp outboard and forked out for a AGM combo starting/trolling battery. Two fishing trips later tach stopped working and could smell burning electrical and found my rectifier had melted very lucky outboard didn't start on fire. This pertains to outboards with rectifier/stator type systems, mine is a 35 amp system. 

   When looking up replacement rectifier CDI electric site has a warning to not use AGM batteries with older outboards. Appears you can only use wet cell lead acid batteries that you can add water to, maintenance free, glass matt, AGM etc have to high of resistance for older outboards. They can only be used with outboards wit alternators on them.

  Just putting this out there to save someone some money my listed for $250 lucky I found it online for $169.

BB if you have one with the rectifier/ stator set up you want a lead acid.

Good topic I wonder though like what year of motor would be compatible with agm battery since I to just spent alot on 2 agm battery for my boat and because my motor is a 98 mercury 40 hp would like to avoid a problem.

Same problem with my ‘89 Evenrude.  Rectifier and power pack. Almost tossed my son out of the boat when they went out at nearly full throttle. 

The repair shop would not even hook up the battery that I had for a year.  

I posted under boats and motors in 2019 about my experience. 

This is true.I had all my ignition electronics recently replaced.

I know a gentleman who has a shop and he says this is a big issue.I ended up dropping some money on the old girl but runs better than ever.

I was told one of the best marine starting batteries is Deka brand,i was also told Interstate marine starting batteries are not a good choice.

I know the company he gets his electronics from is CDI and they warranty their parts for 3yrs.if you have a Deka battery.