Catch 22

[John&Ria]

We are currently in the break-in period for a new 6kw Northern Lights generator . The manual strongly recommends a draw of at least 25-35 amps (50 to 70 percent load) for the first 100 hours of operation. Our Catch-22 situation is that the charging system appears to limit the charging rate to the batteries to only 8 amps if the overall load on the generator goes over 22 amps. As mentioned this is significantly less than what is recommended to properly break in the generator. I can get to the 25 to 35 amp range by running various systems (e.g A/C, auxiliary heaters, etc.), but charging the batteries alone, even at bulk charge rates, only puts a load of about 5 amps on the generator.

Perhaps the inverter can be adjusted to address this situation? I’m a novice when it comes to electrical matters, so I’m seeking the collective wisdom of this forum before sourcing local expertise.

Thanks for any advice that can be provided.

Cheers,

John

[duetto]

hi,

we have/had victron, magnum, and xantrex. all allow you to adjust the maximum rate of charge which in turn will increase the load on genset. with that said i'm not sure the charger alone will provide the load you're looking for. when we run genset in addition to battery charging, we run water heater, electric stove, coffee maker, etc.

we have one of the original entec 4.2kw gensets, so getting the smaller genset to the 50-70% load is easier. years ago the owner of entec told me if possible run "rotary" loads (i.e. pumps, fans, etc) which leads you to ac. he said just turn it on to load up genset.

[John&Ria]

Thanks for your comments John. Our inverter/charger is a xantrex, original to the boat. It looks like I need to read the manual to see what can be done to increase the charge rate. I don’t mind running other systems to get the load up on the generator when we are charging the batteries, as long as I can achieve a high rate of charge and the recommended load rate at the same time.

Thanks again.

[deising]

Relying on the battery charger to load the generator has severe limits because the load falls off as the battery state of charge increases toward full. Something like the main A/C unit is a much better option.

Good luck with your new generator.

[MikeH]

Hi John !

On my Xantrex remote control panel, there is a "power share" button on the right side. Check that it's set to the highest point ">30".

I have a 2010 Xantrex. The manual says that the charger will pull 20 amps, but the highest I've seen on genset is about 12 amps.

[John&Ria]

Hi Mike,

Thanks for weighing in. At max bulk charge to the batteries I have also observed a load of about 12-15 AC amps on the generator (on shore power too for that matter), similar to your experience.

This week I spoke with tech support at both Xantrex and Northern Lights, and learned quite a bit.

Based on what I heard I verified that my inverter/charger is set at the maximum (30 amps), which limits the amount of load I can place on the generator while charging the batteries. From my experience this is a load of about 24 AC amps. Above that the charger automatically decreases the charging rate to the batteries to about 8 DC amps. At that charge rate it takes many hours to fully recharge my house batteries.

When discussing this with the Northern Lights technician he advised that a load on the generator of 24 AC amps is 'acceptable' during the break-in period, even though the manual says a minimum of 50% load (50 AC amps) is required. When using the generator as the power source to charge the batteries, he strongly advised that it's best to add loads from other appliances (e.g. space heaters etc.) as this helps to regulate ('smooth out') the power demands on the generator. Apparently the least desirable thing for the generator is to use it to only charge the batteries. In our ignorance this is something we did frequently with our previous generator, but we won't make that mistake again. Live and learn!

In summary, I'm going to continue doing what I learned from trial and error (i.e. when charging the batteries, use other appliances to set the load on the generator to about 24 amps AC, which will allow for reasonably fast 3-stage charging) and stop worring that I'm not sufficiently loading the generator.

My thanks to all who offered advice.

Cheers,

John