Recharge time with a eu2000

[Dan S]

I just bought the Honda eu2000 and have a lifeline battery (group 27 or 31?). I ran the heater last night but kept it very low as it was only about 40 last night. I also have a 3 year old power max converter.

How long should I run the the generator today to ensure I have a heater fan tonight?

Thanks

Dan

[CanoeStream]

Hour-ish? A bit longer if you can manage it. Haven't tested that exactly but that's seat-of-the-pants from my using the same genset.

How much the furnace motor runs dictates how discharged you become. I find that having good bedding & setting the thermostat so that the furnace comes on maybe every 10 minutes works well -- this often dictates a setting in the mid- to upper 50s. I'll turn it down a couple degrees more if I hear the furnace running every few minutes in the colder predawn hours.

Towing works only slowly -- I've heard it takes towing for 2-300 miles or more to restore charge significantly.

[Dan S]

Thanks.

I'm in the middle of a sea of RV's all tailgating with gens running all around us so running an hour of two is no big woop.

I heard some running all night and they were not low db models!

[idroba]

It also very much depends on your converter/charger charge pattern. I don't know your powermax so I can't say much on what it will do.

A 3 stage converter/charger will do a Bulk charge to begin with, that is dump as much power back into the battery as it will take for a time period that is right for the battery. It will bring the battery up to about 70 to 80% charged quite fast. Usually an hour or two, in my experience. With one battery that you have I would guess an hour. Then it changes into an Adsorption charge, which tapers the charge current off to fill it to about 90% charge. This is much slower and generally takes 3 or 4 hours +. The final 10% is the real time consumer, and takes 24 hours or more. When the battery is fully charged the unit goes to a Float mode, which simply keeps it fully charged, as long as it is plugged in.

So with a 3 stage converter/charger and one battery, at least an hour of generator run time will probably do you OK. With a single stage one the charge is not as fast, and probably 2 hours or more will be reasonable.

If you really want to know what is going on with your batteries, a Tri Metric meter will give you a pretty good idea of where you are. It counts the Amps out, and the Amps in, corrects for efficiency and at any time you can read the % of your battery charge, as well as your rate of charge and rate of discharge. Cost is about $200 with the shunt needed for proper setup.

[DKB_SATX]

If you have a voltmeter, you can tell when the Powermax drops from "bulk charge" at 14.6v to "normal charge" at 13.6v. If you really want to know it's fully charged, you'll eventually see it back off to 13.2v but that takes several hours.

Don't just take one reading and assume it's done with the bulk-charge phase, though, because early in that phase the voltage is slowly rising until it gets to the 14.6v level where it'll plateau for a while before stepping down again.

EDIT: Hehe... timing is everything. All I really added to what idroba had to say is the voltage specs for the Powermax. BTW, the voltages I mentioned are for the Boondocker version of the Powermax converters, the ones that BestConverter sells. I think the only difference for the non-Boondocker models is a lower bulk-charge voltage.

[idroba]

Thanks DKB. So, the Powermax is a 3 stage unit? My experience is all with the Progressive Dynamics line.

[Dan S]

I believe it is a 3 stage.

[DKB_SATX]

Older Powermax converters (that I know of) are 3-stage, and the newer ones are marketed as "4 stage" because they added a desulfating cycle. The older Boondocker model number is PM3B-45 (for the 45-amp) and the new model is PM4B-45.