On my fourth alternator....??

[B.Babs]

I installed drop-in lifepo4 and the first failure they told me was bad diodes. paid for that repair and it happened again two weeks later. They finally sold me a brand new alternator. By week two that alternator basically caught on fire and the internals were totally melted.. They replaced it under warranty now the replacement is burned and dead too? Engine is a Yanmar on a Pearson Sailboat. All this after being sent defective cells for a DIY pack that I gave up on.. Why is LiFePO4 so complicated? I was told you drop them in and go....?I should mention that after the second diode failure I called a marine electrician ABYC who installed an argus FET and Balmar alternator protector but he says only external regulation can prevent the alternator from getting too hot? Alternators have all been stock Yanmar 80A from Mack Booring..Batteries are Battleborn...

 

[efficientPV]

Your alternator has no current limit and is constant voltage, likely about 1/3V more than it should be for lithium.

 

[B.Babs]

Your alternator has no current limit and is constant voltage, likely about 1/3V more than it should be for lithium.

How doI limit the current?

 

[cs1234]

How doI limit the current?

It sounds like you need to install a dc to dc charger. Here is the Victron page.

They will properly charge your lifepo4 battery from your alternator and also limit the charging amps to the battery so you don't harm the alternator. You can either let it automatically detect the alternator is on using voltage sensing, or use a switch to turn it on or off, or use bluetooth to turn it on or off.

You can parallel as many of them as you want to increase the charging amperage, up to the limits of your alternator and the charging limit of your battery. Be sure to leave room for your alternator to power the loads it was originally intended for.

 

[B.Babs]

It sounds like you need to install a dc to dc charger. Here is the Victron page.

They will properly charge your lifepo4 battery from your alternator and also limit the charging amps to the battery so you don't harm the alternator. You can either let it automatically detect the alternator is on using voltage sensing, or use a switch to turn it on or off, or use bluetooth to turn it on or off.

You can parallel as many of them as you want to increase the charging amperage, up to the limits of your alternator and the charging limit of your battery. Be sure to leave room for your alternator to power the loads it was originally intended for.

That was one of the steps. I paid to have a Renology dc charger installed and it failed in four weeks.I suppose that is why my electrician had me sign a waiver that I was on my own for warranty? He said they were nothing but trouble and urged me to return it. Should have listened.

 

[efficientPV]

My solution would be too complicated. A cheap way would add a length of smaller wire from BAT to the
battery and #2 to the BAT. Current would cause a voltage drop and limit current. How many more alternators do you get. This could be tricky.



battery. batt

 

[mikefitz]

Pity you did not ask here before going Lithium.
All sailboats should use lead acid batteries for the engine starter battery for safety and reliability.
If you have a lithium house battery, use a battery to battery charger to charge from alternator power. Your alternator is perhaps a 80A unit, for reliability a B2B in the range 30 to 50 amps should be OK.
The B2B charger connects between the lead acid starter battery and the house battery.


For all my marine installs I only use Victron electrical units.

I was told you drop them in and go.

whoever told you that knowing the application, was either untruthful or had no knowledge of marine systems.

Mike

 

[B.Babs]

That was one of the steps. I paid to have a Renology dc charger installed and it failed in four weeks.

Pity you did not ask here before going Lithium.
All sailboats should use lead acid batteries for the engine starter battery for safety and reliability.
If you have a lithium house battery, use a battery to battery charger to charge from alternator power. Your alternator is perhaps a 80A unit, for reliability a B2B in the range 30 to 50 amps should be OK.
The B2B charger connects between the lead acid starter battery and the house battery.

View attachment 105093
For all my marine installs I only use Victron electrical units.


whoever told you that knowing the application, was either untruthful or had no knowledge of marine systems.

Mike

Battleborn told me that.

 

[Browneye]

Victron FTW.
Friends don't let friends buy renogy. PERIOD

As so well explained already, you need a regular starting battery for your engine, isolate your house circuit with the lifepo4 battery(s) and a Victron DC to DC charger. Live happily ever after.

Got a solar panel and charge controller too? Or do you plug in. Unless you motor every day you may want to consider an alternate charge source for your house batteries.

Don't listen to BB. They make a nice battery, but tend to over-simplify on the ancillaries and applications.

 

[B.Babs]

Victron FTW.
Friends don't let friends buy renogy. PERIOD

As so well explained already, you need a regular starting battery for your engine, isolate your house circuit with the lifepo4 battery(s) and a Victron DC to DC charger. Live happily ever after.

Got a solar panel and charge controller too? Or do you plug in. Unless you motor every day you may want to consider an alternate charge source for your house batteries.

Don't listen to BB. They make a nice battery, but tend to over-simplify on the ancillaries and applications.

Yes I learned that the hard way. What a terrible company to try and deal with they do not answer phones.

 

[Browneye]

You even have to be careful with how much you pull using a dc to dc - you need to calc alternator output and existing loads, then size your converter/charger to suit.
The nice thing about a victron is it's easy to turn it off with the BT app if you have a heavy intermittent load on your starting circuit, like windless, power halyards, search or spreader lights, etc. Normal running loads shouldn't be much, maybe navigation lights is all, and charge the starting battery.

The problem with lifepo4 is there is so little internal resistance that they will pull all your alternator can put out, so especially at idle it just never gets a rest and overheats. Here's learning the hard way.

I don't know why BB insists their batteries are 'drop in' - they're just not. Traditional/existing charging sources for lead acid batteries are generally not well suited for lifepo4. The whole charging profile is different, and especially they need to stop charging when they're full - FLA you can just keep charging them, they love it, burns off any plate-sulfating. Beware any 12V converter/charger as well - may well overcharge them.

I went with the Victron Orion 18A charger, not wanting to overload the 145A alternator on a Winnebago. It's hard to judge loads with a whole chassis, and all the 'to-go loads' are on that circuit - power awning, slide outs, power step, leveling jacks. The house battery stays pretty well charged with the solar panels, so driving is just an additional charge source for lots of rainy days or at night. It is set to a fairly low charge voltage so it terminates before they get completely full. The charge cycle starts over each time it powers on, which can happen a number of times while driving cross country. The boost/bulk mode timer has a minimum duration of 30 minutes, so that starts over each time you start the engine. It does taper current though, so if the battery gets near full it doesn't over charge them.

 

[svsagres]

How doI limit the current?

You have two ways of managing your alternator when charging LiFePO4.

Option 1, as others have mentioned, is to use a DC:DC charger and leave your alternator connected to a lead acid starting battery.

Option 2 is to get your alternator modified for external regulation (or buy one such), and get yourself an external intelligent alternator regulator that will monitor your alternator temperature (and other parameters) and drive your alternator appropriately.

I have a Wakespeed WS500 driving my alternator, and while not cheap, it makes having a large alternator (85A)on a small engine (Yanmar 1GM10) viable. It also fully integrates with my power system and will only generate the power my BMS calls for, both voltage and current.

The Balmar regulator can also be setup to manage lithium, but they don’t integrate and don’t have knowledge of current, but they do monitor alternator temperature and will keep it from burning out.

 

[pacman]

The Is nothing like drop in for nautical applications.
Unfortunately, if you would like to go lithium on a boat, all the system should be reviewed accurately.
Lithium batteries take so easily the charge that, as already said, without external regulation any alternator will burn after a while. You can find a lot of interesting and educative material around the Web; two starting sites can be: marinehowto.com and nordkyndesign.com.
Anyway, seen the pictures you published, I would say that your cells suffered from chronic overcharging.
Be aware that you can overcharge a LiFePo4 cell even at 3.4 volts if you keep a current flowing from a charging source.

 

[mikefitz]

What pictures?

 

[pacman]

My apologies, I was answering two threads and my pc crashed, when I resumed it and connected to the forum I mixed up the two threads.
Apart the pictures reference, all I wrote is indeed valid. I am going to modify my reply.

 

[DJSmiley]

As @svsagres says:
Go for a DC-DC if you don't need high amps and/or share the alternator for other purposes

or

With a dedicated alternator go for a dedicated controller like a Wakespeed and archieve full amps depending on the alternator used. 100A no problem.

There is no such thing as drop-in. Lead-acid and LiFePO4 are different chemistries. Everyone selling it as a drop in is just plain wrong.
It *might* work, depending on the configuration, but its higly risky to assume this.
And even if does work, that's not how it should be installed properly. Charging profiles are different. Using a 14.6V constant power might work but its not recommended for the lifespan of the lithium battery..

 

[Levo]

One question I have fielded in a related thread: What are the normal and maximum surface temperatures for a typical stock vehicle alternator?

I have just completed a season using 40A DC-DC charger (with "halvable" current switch). The 160A (nominal) alternator seems fine supplying the extra 40A, but knowing the permissible temperature would give me more confidence.

Anyway, I have found no reference or spec sheet with such info, and nothing definitive from posts in the forum. How hot is too hot?

 

[Browneye]

That is a fairly common question, with lots of replies in a google search. From cruising forums, to corvettes, trucks, and on and on.
Lots of results for: 'alternator how hot is too hot'.

The general consensus is 70-100C is max. One comment I saw said diodes start to degrade at 70C. That's about 160 degrees F.

If it's smoking it's too hot.

 

[Levo]

That is a fairly common question, with lots of replies in a google search. From cruising forums, to corvettes, trucks, and on and on.
Lots of results for: 'alternator how hot is too hot'.

The general consensus is 70-100C is max. One comment I saw said diodes start to degrade at 70C. That's about 160 degrees F.

If it's smoking it's too hot.

Must admit, that range is a little lower than I expected. My searches mostly brought up chatter, anecdotes and vague terms rather than specifics, and no OEM info.

When I start towing again in the Spring, I'll be measuring with a non-contact thermometer and sticking with 20A charging if need be. Have you measured temps on yours?

 

[Browneye]

No, mine is on a 8.1L GM gas V8, 145A. My Orion is a 18A. I really never worried about it.
I know the hydraulic leveling jack motor will dim the lights. LOL