Putting in a 90 amp alternator, do you have to change your battery


Information and questions on GL1500 Goldwings (1988-2000)
Post Reply
User avatar
ShannonFoster69
Posts: 3
Joined: Sun Apr 17, 2022 1:52 am
Location: United States
Motorcycle: 1989 GL1500

Putting in a 90 amp alternator, do you have to change your battery

Post by ShannonFoster69 »



I was just curious if I had to change my battery, I have a duralast Gold battery in it now if I put in a 90 amp alternator on my 89 Honda GL 1500


User avatar
Rambozo
Posts: 3700
Joined: Sun Apr 01, 2018 8:36 pm
Location: Disneyland
Motorcycle: 1992 GL1500 Aspencade
Ducati Monster

Re: Putting in a 90 amp alternator, do you have to change your battery

Post by Rambozo »

As long as your battery tests good, no need to replace. You do have to replace your main dogbone fuse. Usually, you just double them up to deal with the higher current.
User avatar
blupupher
Posts: 786
Joined: Sun May 17, 2020 5:47 pm
Location: Katy, Republic of Texas
Motorcycle: 2013 BMW K1600GT

Re: Putting in a 90 amp alternator, do you have to change your battery

Post by blupupher »

If your current battery is good, no need to change it.

I did not "upgrade" my dogbone fuse.
My view is the dogbone is meant to protect the wiring of the bike, which is rated to 55 amps. Just because it is a "90 amp" alternator does not mean it is putting out 90 amps.

I put on a 95 amp LActrical because I was tired of having only 12.4v at < 1300 rpm's and dealing with dimming lights when sitting at a stoplight with the turn signal on.
Plus the LActrical was a good price with decent reliability compared to any other 40 amp unit.
Current ride: 2013 BMW K1600GT

Former rides: 2002 GL1800A, 2001 CB750, 1994 GL1500 SE, 1994 VT1100C , 1984 VF500F, 1982 CB750C, 1982 GS250T, 1981 CB900C, 1978 CB125s, 1976 TS185
User avatar
DenverWinger
Posts: 2441
Joined: Thu Jun 23, 2011 2:20 pm
Location: Denver, CO
Motorcycle: (s)
'80 GL1100 STD Vetter (2005-)
'93 GL1500 Aspencade (2017-)
'83 Trav-Lite Camper (2010-)
Past rides
'72 CL350 (1980-1988) sold
'78 Suzuki GS550 (1985-2005) sold
'77 GL1000 (2002-2006) sold

Re: Putting in a 90 amp alternator, do you have to change your battery

Post by DenverWinger »

blupupher wrote: Sun Nov 06, 2022 7:49 pm My view is the dogbone is meant to protect the wiring of the bike, which is rated to 55 amps. Just because it is a "90 amp" alternator does not mean it is putting out 90 amps.
+1 on that. I too have high output alt. Just because the alternator CAN output 90 amps doesn't mean it WILL output 90 amps. The alternator (controlled by the regulator) will only output as much as the bike asks for to hold the correct charging voltage, on my bike it has never exceeded the capacity of the 55 amp dogbone.
A local inventor has figured a way to turn a sausage grinder backward to manufacture pigs. :lol:

♫ 99 Little Bugs in the Code, ♪
♪ 99 Bugs in the Code. ♫ :(
♫ Take one down, Patch it around, ♪
♫ 127 Little Bugs in the Code. ♫ ♪ :shock:
~Mark
User avatar
Nlmman47
Posts: 148
Joined: Thu Mar 31, 2022 8:03 am
Location: Middlesex, NC
Motorcycle: 1993 GL1500 Goldwing Aspencad

Re: Putting in a 90 amp alternator, do you have to change your battery

Post by Nlmman47 »

is it real hard to change the alternator i might want to change mine
User avatar
Rambozo
Posts: 3700
Joined: Sun Apr 01, 2018 8:36 pm
Location: Disneyland
Motorcycle: 1992 GL1500 Aspencade
Ducati Monster

Re: Putting in a 90 amp alternator, do you have to change your battery

Post by Rambozo »

Pretty easy job. Some of the aftermarket ones like Compufire are a bit larger so it can be tricky to get them positioned to fit in the space. Plenty of people have done it on the side of the road. :shock:
User avatar
blupupher
Posts: 786
Joined: Sun May 17, 2020 5:47 pm
Location: Katy, Republic of Texas
Motorcycle: 2013 BMW K1600GT

Re: Putting in a 90 amp alternator, do you have to change your battery

Post by blupupher »

Nlmman47 wrote: Mon Nov 07, 2022 1:46 pm is it real hard to change the alternator i might want to change mine
Really not that hard. Several youtube videos and I think there is a how to with pics here on the site.

The biggest pain is having to take off most of the plastic on the left side to get to the wire from the alternator to the main harness.
The rest is pretty simple. Take off both side panels on both sides, disconnect battery, 3 bolts on the alternator, 1 nut for the power, and the above mentioned plastics to disconnect 1 wire (some just clip and splice the wire).
It is recommended to use new isolators (the "bushings" that cushion the alternator from the engine).
Installing a 40 amp is super easy, my 95 amp was not that much harder (just try to remember the angle that allowed you to remove it, installation is just the opposite, and my 95 amp was really not that much bigger). Getting the splines lined up was a bit of a pain, but not that hard.
The rest is just the opposite of removal.
I was maybe 2 hours total time, and I took my time.
Current ride: 2013 BMW K1600GT

Former rides: 2002 GL1800A, 2001 CB750, 1994 GL1500 SE, 1994 VT1100C , 1984 VF500F, 1982 CB750C, 1982 GS250T, 1981 CB900C, 1978 CB125s, 1976 TS185
User avatar
newday777
Posts: 2422
Joined: Tue Jan 11, 2011 5:21 pm
Location: Milford NH
Motorcycle: 2008 Cabernet Red. Level 4 bought at 15,000 now 172,000

1975 CB750 K5 Planet Blue 11,00 miles

Project bikes
1976 CB750 K6 Anteres Red 25,000 miles, 2 more K6s, 1 K4, 1 K8

Past rides
1983 GL1100A Wineberry 63,000 miles(sold)

1999A Restored from PO neglect & sold at 19,000 miles

1999SE Totaled by cager at 105,000 miles

Re: Putting in a 90 amp alternator, do you have to change your battery

Post by newday777 »

ShannonFoster69 wrote: Sun Nov 06, 2022 6:57 pm I was just curious if I had to change my battery, I have a duralast Gold battery in it now if I put in a 90 amp alternator on my 89 Honda GL 1500
As long as it is an AGM battery that is still good, you'll be fine.
Limpy45
Posts: 57
Joined: Mon Jan 11, 2021 2:42 pm
Location: Grand Forks, ND 58201
Motorcycle: 80 GL1100 standard and a 99 GL1500 SE

Re: Putting in a 90 amp alternator, do you have to change your battery

Post by Limpy45 »

The only thing you have to change is possibly the battery when it expires by itself. Just check it frequently to add water if it is not a sealed
battery. AGM is recommended with a higher amp alternator. The fuses will be just fine as they are. I have a Dodge Caravan with a 110 amp alternator and all the fuses are the same value as on my old VW diesel I used to have. The fuses are to protect the vehicle wiring from a fault, not to limit amperage in the charging system. Sorry if I offend anyone by this, but study some books on automotive charging systems. That is basically what our motorcycles have, except for 4 cylinders and HD's.


Post Reply