Shredded belts after lifepo4 upgrade

[Dave Lochner]

We went through this issue last summer after an upgrade to a 165 a Balmar with a Balmar serpentine kit. The core problem was the tension and load on the belt was greater than the single adjusting tensioning bolt on the alternator could cope with. The alternator would gradually slip, the looser belt would then rub against an engine fitting wearing a groove in the belt until the belt shredded.

The solution was to use a Balmar Belt Buddy and adjustment arm.

[IBlake]

BenCo Sorry, I didn't see your post that you already have Serpentine belts. Try different tension on belts, maybe too loose.

[IBlake]

BenCo I agree with Dave Lochner above.

[swisel]

As a workaround, consider trying a belt dressing product; usually in an aerosol.

[j.g.evans]

I had a similar problem going to a 100 A Balmar. Balmar suggested going to a larger sheave which they provided free. Single belts now last for many years.

[PineyWoodsPete]

Originally Posted by j.g.evans

I had a similar problem going to a 100 A Balmar. Balmar suggested going to a larger sheave which they provided free. Single belts now last for many years.

Great suggestion! I still don't get the OP's reticence to share specs of his alts. and battery banks - the "lifepo4 upgrade" that started the alt. belts a'shredding...as in trying to pump 200A/12V into the bottomless pit of a depleted 10 kWh lithium bank?

[Phil_Fr]

Originally Posted by BenCo

Hello all,

The alternators were retrofitted for lifepo4 and connected to mc614 Balmar voltage regulators and cyrix-li-ct to keep the lead acid starter batteries topped off.
Unfortunately since the upgrade I have been shredding belts one after the other and I can’t explain it. Does anyone have advice to get this working well and stop the belt massacre? Thank you in advance

You have retrofitted alternator, right, but name, type of alternator, type of belt and pulley can help.

Did you move or remove the alternator > misalignment.

[MJH]

Originally Posted by BenCo

Hello all,
I have a newly upgraded electrical system with 1400w of solar (4x350LG panels) on 2 mppt 100/50 victron that feed into 2 x multiplus 2000w inverters.
The alternators were retrofitted for lifepo4 and connected to mc614 Balmar voltage regulators and cyrix-li-ct to keep the lead acid starter batteries topped off.
Unfortunately since the upgrade I have been shredding belts one after the other and I can’t explain it. Does anyone have advice to get this working well and stop the belt massacre? Thank you in advance

With 1400W of solar you should not be needing much augmentation from the alternators unless you are using excessive electrical power...something isn't right. Sounds like your alternators are undersized and your solar isn't charging like it should.

The general rule on alternator size is 25% of the total battery bank your charging. I assume you have two engines, one alternator per engine. What are the alternator sizes? What is the total battery bank wattage?

You didn't give your location. Do you have sufficient sunlight this time of year?

Starter batteries generally don't need too much to top them off. It is the house battery bank that needs more charging. I think an Automatic Charging Relay, such as a Blue Seas System #7610, would ensure your starting batteries are always full.

Using the Balmar MC-614 you can reduce the load on the alternator which should reduce belt ware. Look at the instructions.

Lastly, I suggest calling Balmar tech support and pose your issue. I have found them very helpful for many years.

Good Luck.

~ ~ _/) ~ ~ MJH

[DeValency]

Originally Posted by MJH

With 1400W of solar you should not be needing much augmentation from the alternators unless you are using excessive electrical power...something isn't right. Sounds like your alternators are undersized and your solar isn't charging like it should.

The general rule on alternator size is 25% of the total battery bank your charging. I assume you have two engines, one alternator per engine. What are the alternator sizes? What is the total battery bank wattage?

You didn't give your location. Do you have sufficient sunlight this time of year?

Starter batteries generally don't need too much to top them off. It is the house battery bank that needs more charging. I think an Automatic Charging Relay, such as a Blue Seas System #7610, would ensure your starting batteries are always full.

Using the Balmar MC-614 you can reduce the load on the alternator which should reduce belt ware. Look at the instructions.

Lastly, I suggest calling Balmar tech support and pose your issue. I have found them very helpful for many years.

Good Luck.

~ ~ _/) ~ ~ MJH

+1 Finally the answer I think is the most appropriate!

As it looks, there is an excessive output current demand by the new batteries, this creates a higher resistance by the alternator and overload the belts. The Balmar external regulator can be adjusted to a lower output, but probably the more important step is to first adjust the Victron DC-DC chargers to lower current (say 15-20A) and check the alternator output current (before and after changing the settings).

Misalignment of the alternators sounds less possible as what the OP says is the issue is with both engines alternator AFTER the new batteries were installed

[CaptainRivet]

Originally Posted by captstu

On a previous catamaran, I fitted a 200 A alternator to each engine. The alternator was driven with a second drive pulley, a duel belt system using "high power" belts by various manufacturers.

They all failed after about 200 hours. I think the alternator was demanding demanding more power than they could deliver - even though I had a slow-start Balmar regulator.

I just changed belts often - even after professional alignment checking, each time I accelerated the engine, the belt slipped until the alternator caught up.

The answer, I found years later, was a toothed high power belt. Change out the drive pulley, install a dedicated toothed drive pulley, and you won't eat any more belts.

BTW, both my 3GM35F engines failed after 5000 hours due to excessive heat. The extra power demands were more than the engine cooling would support. Even after the rebuilds, the setup was less costly than an auxiliary generator. And, it provided underway air conditioning, a washer and dryer, and ample power via 1200 Ah of flooded cells and a 3kW inverter.

You don't need a genny but additional cooling off the engine.
Lessons learned, high current alternators on small diesels already on the limit speced by producer need additional cooling
Was wondering how long it takes till this comes up. A 100A constant charge eats between 8 and 12hp, if you have the underpowered standard engines its in constant stress and limit, even with the 10hp more optional engine.
30hp with the 115A Mitsubishi alternator that can deliver 70A constant on a 12t Lagoon 400S2 is already totally in the limits.... Additional cooling required....Lagoon spec LFA that never pull more then 30A from the alt....

[PineyWoodsPete]

Originally Posted by CaptainRivet

You don't need a genny but additional cooling off the engine.
Lessons learned, high current alternators on small diesels already on the limit speced by producer need additional cooling
Was wondering how long it takes till this comes up. A 100A constant charge eats between 8 and 12hp, if you have the underpowered standard engines its in constant stress and limit, even with the 10hp more optional engine.
30hp with the 115A Mitsubishi alternator that can deliver 70A constant on a 12t Lagoon 400S2 is already totally in the limits.... Additional cooling required....Lagoon spec LFA that never pull more then 30A from the alt....

OK, 100A @ 12.5V is 1.25kW, or about 1.7HP. With your 8-12 engine HP estimated needed for this, your efficiency is in the range of only15-20%. My understanding is that alternator efficiency is in the 60-80% range, giving only a 2-3 HP draw. Where are your numbers coming from?

[CaptainRivet]

Originally Posted by PineyWoodsPete

OK, 100A @ 12.5V is 1.25kW, or about 1.7HP. With your 8-12 engine HP estimated needed for this, your efficiency is in the range of only15-20%. My understanding is that alternator efficiency is in the 60-80% range, giving only a 2-3 HP draw. Where are your numbers coming from?

Alternator efficiency is bad around 20-25% in reality and not 60%,thats theoretical Wikipedia nonsense. Why do you think they need to be so beefy to really withstand the heat and need an external regulator to manage heat....
The wildly used 115A Mitsubishi alternator produces 1000W heat (in a well ventilated cat engine room) when delivering 30A,measured that myself and thats already a quite good and efficent one...
With 60% efficiency i would mount a heavy duty 300A alternator on each engine and run them all 2 days for 30min (which happens anyhow going into an anchorage) ..but well on these levels your lucky to get 20%,mostly around 15% with these monsters...
The less RPM, the less cooling, the less efficiency

[PineyWoodsPete]

Originally Posted by CaptainRivet

Alternator efficiency is bad around 20-25% in reality and not 60%,thats theoretical Wikipedia nonsense. Why do you think they need to be so beefy to really withstand the heat and need an external regulator to manage heat....
The wildly used 115A Mitsubishi alternator produces 1000W heat when delivering 30A,measured that myself and thats already a quite good and efficent one...
The less RPM, the less cooling, the less efficiency

Then I'm wondering why the portable air-cooled gas-powered 5kW genny's only need a ~0.4 L engine producing ~11-12 HP at continuous full output? There's little difference in generator vs alternator output native efficiency...

You might check out the Chainsaw Journal, where I get my info...

[CaptainRivet]

I knew that exactly this would come.... There is a big difference in genny and inboard propulsion diesel with an off the shelf alternator to fullfil the minimum spec of the boat manufacturer.
Again i don't know how you run 5kw with only 0.4l gas,you seem to have magic engines.
Honda eu22i needs 1l per hour running 1800W. You can find this in reviews and its a very efficent one.
That is a genny running in the optimum range of an optimized engine exactly for that purpose.

[PaulCrawhorn]

If you can keep it under 3.5HP per kW that's pretty good IRL.

A 200A alternator at 12VDC will likely take at least 8hp and needs either a dual vee or a serpentine belt to drive it.

A purpose built dedicated DC genset by German engineers might get near 2HP per kW.