On my fourth Alternator?

[B.Babs]

I installed drop-in lifepo4 and the first failure they told me was bad diode? paid for that repair and it happen again two weeks later. I finally bought a brand new alternator. By week two that alternator basically caught on fire and the internal componentry were totally melted. It looked like burnished maple syrup. They replace it under warranty. now the replacement is burn and dead too? Engine is a Yanmar on a Pearson Sailboat. All this frustration after being sent defective cells for a DIY project that I finalle gave up on..

Why is LiFePO4 so complicate? I was told drop them in and use(by the manufacturer.....? I should mention that after the second diode failed I called a marine sparkie ABYC who installed an argus FET and Balmar alternator protector but he says only external regulator can prevent alternator from getting too hot? Alternators have all been stock Yanmar 80A from Mack Booring..Batteries are groupe 31 Battleborn...I have now spent more on alternators than I did on batteries. I ran AGM for last 17 years with no issues other than only lasting 2-3 years.?

[smac999]

a stock alt charging a lithium bank is going to cook... lithiums are not drop in..

an external regulator with temp sensor and max current limiting is one way.

[Sailmonkey]

I’ll second the “lithium are not drop in” sentiment.

You’re going to continue to cook alternators until you have some way to control the alternator.

[PippaB]

Small case alternators will rarely (ever?) provide their rated power for very long without dying of heat exhaustion. Internal regulators don't deal with this, so the only way to get there is external regulation with current limiting and temperature sensing.

Another consideration is engine speed - at what RPM are you trying to charge your lithium? In the bad old days of LA you could charge at high idle and the drop off in current was so quick that your were OK. Since current intake by LiFePO4 doesn't taper much, you need better cooling. Without adding some form of external cooling, better cooling on a stock alternator comes from higher RPM. The fan on the alternator turns faster, moves more air, and provides more cooling.

[Scott Berg]

1) there is NO SUCH THING as a drop in LI battery 2) work with an experienced professional to design a compatible charging system 3) if in the US or Canada review the recently released E13 standard

[Paradox111]

https://www.youtube.com/watch?v=XAOhT2HwKWM

[mrcarson]

Li-Po are different to Li-Ion. I had to buy a different charger for my battery's That did both with separate setting on switch.and that was around 5 yrs ago. Still charging well and cutting out at set ampage. AC Alt, to 3 way (Recharge/Li-Ion/Li-po) Charger to Battery/s I bought from Internet from China.

[NPCampbell]

Originally Posted by B.Babs

I should mention that after the second diode failed I called a marine sparkie ABYC who installed an argus FET and Balmar alternator protector but he says only external regulator can prevent alternator from getting too hot?

The alternator protector will guard against a "load dump" which occurs when the battery management system in the drop-in LFP cuts off when the battery is full.

However, it won't guard against the alternator overheating. The overheating problem can actually be worse when your engine RPM is low because at high RPM the fan mounted on the alternators output shaft is providing cooling. At low RPM, the load is still there but there is no cooling.

There are alternator + regulators that will limit current based on temperature.

[Q Xopa]

The first thing I recommend is some education. You have come to the the right place as there is a lot of discussion about Lithium issues on here. However I suggest the most concise source to start is https://marinehowto.com/drop-in-life...ated-consumer/

As it seems you have found being a ABYC Sparky is not a guarantee they know or understand everything about these, or know the best solutions.

I agree with the previous posts that Lithium are NOT drop in, as marketed.

Charging as you have learnt the hard, ie expensive way is a lot different.

The other bad news is that education does take a bit of an investment in time.

Apart from not being 'drop in' the other issues are that the fix isn't quick, simple or cheap.

But if you learn a bit and get them going right they are great.

As the previous guys have said a good start is-

External customizable regulator with temp sensors- Wakespeed or Balmar,

A heavy duty Alternator, large cases are better. They require around an extra inch wider.

Multi rib drive belts and pullies,

Alternator protection device, either Sterling or Balmar.

Some wiring, solar chargers, shore chargers may need to be upgraded.

Speaking of ABYC, they are bringing out their new Lithium battery guidelines soon. Which many Insurance companies follow. One of the touted recommendations is likely to be communication between batteries and chargers and warning of impending disconnects.

Some people are lucky and get away with doing nothing. But I dont think anyone here would recommend it.

So the above list doesn't sound so 'drop in'.

[goboatingnow]

You don’t need a new alternator. You need a better alternator regulator, one with temperature monitoring

[Q Xopa]

Originally Posted by goboatingnow

You don’t need a new alternator. You need a better alternator regulator, one with temperature monitoring

Agreed regulator is IMO the best place to start.

As for needing a new Alternator, none of it, including Lithium batteries, is 'needed'.

The PO didnt give many specifics, so making a few assumptions. The Battleborns charge acceptance rate is 100A, but better 30-50A each. Most house banks have more than one battery.

I dont know what he has but 'standard' Alternator is 'cold' rated 60-85A.

This means that the Battleborns are not going to be charging at what they often want.

That's all fine but seems like a waste of potential time and diesel saving capacity that you paid good money to get.

It also means that poor little Alternator is going to be running flat chat/ BTTW. Of course we know how things last whe run at their max limit. 4 Alternators later I'm pretty sure the OP has a good idea.

Of course as correctly stated with an adjustable external regulator this can be de rated. This circle back to my previous comment about wasted Lithium charging capacity.

I agree a new Alternator is NOT needed. Point well noted.

[Rumrace]

You have a dead short or a broken ground.
I’d get an electrician in with one of those spooky machines which read continuity through walls. My best friend happens to be tech expert on all things wired. He says my lithium are nothing special but the chargers are. I have a Bosch liquid cooler serpentine belt on a Yamar with Honda billet pulleys.
I think we wrecked Yamars warranty
The Bosch has a circuit to protect itself. Some type of zeener diode I suspect
He found some UL CSA code violations. The French boats version of a 120v outlet was not in a proper box nor ground fault. Made him so angry he wrote Jeanneau a letter and he’s not a boater.

[rgleason]

Totally agree. He needs a wakespeed ws500 or balmar mc-618 external regulator with belt manager or field limiting adjustible control and an alternator thermal sensor.

What a waste. The alternator will need to be using the external regulator, obviously.

[BobFord]

Perhaps of interest to you- I had a series of failures with a 24v add on alternator. The problem was finally traced to overheating ,on turn off . It seems that the device holds a lot of heat , as soon as it's inbuilt fan stops , the device 'cooks', Answer was a blower aimed directly at the alternator. This dissipated excess heat whilst it was running . Definately prevented overheating .

[Maine Sail]

Originally Posted by Paradox111

Neither the ISO (European standards) nor North American Standards allow this..