Battery Light in cockpit coming on after new alternator installed

[tfox2069]

I recently had a local diesel mechanic install a new externally regulated 80 amp alternator with a Wakespeed WS100 regulator to replace the OEM 60 amp internally regulated alternator on a 2008 Yanmar 3YM30. This was the last piece in a full battery/charger upgrade which included 2 new Firefly Group 31 batteries (232ah total) and a Sterling ProCharge Ultra 60 amp shore charger. I manage my charging system through a Victron BMV-712 battery monitor and the Victron Bluetooth app.


Since the install, after 45 or so minutes of motoring the red battery charge light comes on at the B panel in the cockpit, and the #5 error light comes on at the WS100. Typically the B panel battery light indicates the alternator is not charging - but the Victron says this is definitely not the case, and the alternator is putting out a charge to the batteries. The WS100 #5 error light means either batteries are overheating (they're not according to the Victron, and that lead is not hooked up to the WS100), the alternator or the regulator is overheating (the alternator temp lead IS hooked up, but a temp gun confirmed neither the alternator nor the regulator are overheating), or low or high system voltage (neither is indicated on the Victron - always above 13 and below 14 volts).



Neither me nor my mechanic can figure this out. It only seems to go away if I open up the engine cover and flood fresh air through the engine area, even though the highest temp item is 192 degrees fahrenheit (the alternator belt). Everything is within normal range of temperature that I can hit with the temp gun.


I'm attaching some data from a run I did this past Sunday if anyone is interested in taking a look. We're stumped. Any ideas? Troubleshooting advice?

[smac999]

unpluge the temp sensor from the reg for a min and see if the light goes off? it it does you know the issue is the heat sensor.

192 sounds pretty hot to me.

the balmar reg would tell you the alt temp it's reading. never used your reg before.

that 80a alt is barly charging. it's bulk charging at 40a

18a at 1200rpm is also very sad

[tfox2069]

Good troubleshooting thoughts. The manual on the WS100 actually advises against disconnecting the temperature sensors while the regulator is energized. BUT, I did so when underway, not having read that bit of the manual, and it did not make any difference (lights still illuminated), so that rules out the alternator overheating (also, the engineer at Wakespeed advised me to try the same thing, so I think its probably pretty safe!)


192 was the temperature of the hottest thing in the engine compartment - the running alternator belt. I would expect, due to friction, that the belt would be pretty hot while being run. Everywhere else was 120-130, so that didn't concern me.


A further talk with the Wakespeed engineer revealed an undocumented setting in the regulator itself that signals overtemp at 150 degrees, which is possible INSIDE the regulator box at the temps I was shooting on the outside of the box. Such an overtemp reading inside the box would cause the regulator to shut off alternator output until the temp dropped below 150. We think that's exactly what's happening.


It turns out Wakespeed has been working on this issue for awhile, and are now manufacturing their WS100 with a higher max temp of 200, which they believe is safe (and may go higher). They are willing to exchange a newer WS100 at no charge and see if that solves the issue. If not then relocating the WS100 outside the engine compartment will definitely do it. That would be a PITA, so I'm hoping the updated WS100 will do the trick. Swapping that out will be a 10 min job.



I'll update when I get things in place and test it out. FWIW Wakespeed has been great to work with and I really love the simplicity of their regulator.

[witzgall]

What is the make of the Alternator? Without sounding like I am trying to push our products, there are differences in alternator construction that can affect the units tolerance for heat. As long it is from a reputable manufacturer, you should be good.

One of the #1 sources of heat in an alternator installation can be incorrect belt alignment and tension. If that is the hottest point you are measuring, I would double check that it is tensioned properly with good alignment.

Chris (From Balmar)

[tfox2069]

Chris - appreciate the very valid thoughts. The alternator is conservatively rated and hand built by Compass Marine out of Cumberland, Maine. Its not a Balmar, but it is a Rod Collins special


I don't have a reference temp for the running alternator belt (e.g. what the old belt's temperature was when running), so I have no way of knowing whether the temp on the new belt is high. It's already operating in an ambient temp around 140 degrees, so I would expect that with the added friction of a running belt it would be noticeably higher in temp than anything else. What I might do is shoot the temp of the alternator belt on my 4Runner and to get an idea of whether its way out of range, or roughly in the same ballpark. If anyone has ever checked the temp of their alternator belt while under load in a heat soaked engine compartment I'd be very interested to hear.



Belt tension is something I checked, both at initial installation and then after re-tensioning after a few hours of break in. I also upgraded to a toothed Gates Green Belt as the OEM Yanmar belt wouldn't fit the new alternator. So I think we're good there.


Alignment is something I have NOT checked, and will do so this weekend. It wouldn't be the first thing I found the mechanic hadn't squared away when installing the new alternator (e.g. hooking up the tach, sigh).

[witzgall]

You are good with Rodd, he takes this stuff seriously. just check that alignment, so you can tick that off of the list as an issue. Do you have good engine room ventilation? Or even ok ventilation?

Chris

Originally Posted by tfox2069

Chris - appreciate the very valid thoughts. The alternator is conservatively rated and hand built by Compass Marine out of Cumberland, Maine. Its not a Balmar, but it is a Rod Collins special


I don't have a reference temp for the running alternator belt (e.g. what the old belt's temperature was when running), so I have no way of knowing whether the temp on the new belt is high. It's already operating in an ambient temp around 140 degrees, so I would expect that with the added friction of a running belt it would be noticeably higher in temp than anything else. What I might do is shoot the temp of the alternator belt on my 4Runner and to get an idea of whether its way out of range, or roughly in the same ballpark. If anyone has ever checked the temp of their alternator belt while under load in a heat soaked engine compartment I'd be very interested to hear.



Belt tension is something I checked, both at initial installation and then after re-tensioning after a few hours of break in. I also upgraded to a toothed Gates Green Belt as the OEM Yanmar belt wouldn't fit the new alternator. So I think we're good there.


Alignment is something I have NOT checked, and will do so this weekend. It wouldn't be the first thing I found the mechanic hadn't squared away when installing the new alternator (e.g. hooking up the tach, sigh).

[tfox2069]

Engine room ventilation is OK - not great. I run the blower exhaust, which helps, and I've never noticed any overheating there by smell, visual cue, lights or a temperature gun, until this regulator was installed. The regulator is also installed in probably the absolute worse place - near the top of the compartment and above and behind the alternator, so I imagine it gets the most heat possible when the compartment is closed.



I'll def check pulley alignment this weekend.