Charger: Incorrect absorption and float voltages

Yoshimura · 10-15-2018, 06:57 PM

Hello,

My LW2000 inverter/charger is set to AGM2 but instead of the expected 14.6V absorption and 13.7V float voltages, the voltages are respectively 15V and 14V. Should I have the inverter/charger verified?

Thanks!

markopolo · 10-15-2018, 08:02 PM

I would get that checked.

Are you checking with your own multi-meter or is that from the inverter display?

Do you have Lithium or AGM batteries?

Yoshimura · 10-15-2018, 08:05 PM

I have a AGM battery and the measurements are from the panel voltmeter and a multimeter.

booster · 10-15-2018, 08:05 PM

Does that charger have temp compensation, maybe built internally so no battery sensor? OP looks to be in Canada, so it could be cold enough to see those kinds of voltages.

cruising7388 · 10-15-2018, 08:45 PM

Quote:

Originally Posted by booster

Does that charger have temp compensation, maybe built internally so no battery sensor? OP looks to be in Canada, so it could be cold enough to see those kinds of voltages.

The Powerstar units have a temperature compensation RJ-11 port but AFAIK, since there may be multiple batteries at different ambient temps because of their different locations, Roadtrek doesn't implement any battery temp sensing probe. FWIW, the charger powers up in the boost mode for a programmable time period which perhaps accounts for these readings although I have never seen shoreside charging voltages this high on our 2017 210. These units are programmed for a specific VIN, so the program parameters should be looked at to ensure the charging profile is compatible with the batteries installed.

booster · 10-15-2018, 08:49 PM

Many chargers that have temp compensation ability but no sensor attached at an input will revert to an internal temp sensor for the compensation, which is certainly better than nothing. It would be interesting to see if that is the case with that charger.

markopolo · 10-15-2018, 10:32 PM

That would end up being the same as no temperature compensation if the interior of the van is maintained at say 72F for comfort.

Yoshimura - can you tell us what brand and model # battery you have? It might be easy to lookup the recommended charge profile for the actual battery.

I recall that the 185Ah battery used in the Zion had peculiar charge requirements and maybe yours is the same brand.

booster · 10-15-2018, 10:38 PM

Quote:

Originally Posted by markopolo

That would end up being the same as no temperature compensation if the interior of the van is maintained at say 72F for comfort.

Yoshimura - can you tell us what brand and model # battery you have? It might be easy to lookup the recommended charge profile for the actual battery.

I recall that the 185Ah battery used in the Zion had peculiar charge requirements and maybe yours is the same brand.

Yes, that is absolutely true if the van temp is at 72*, but if the van is stored outside in Canada in cold weather, the inside of the van would be at ambient, so this time of year might only be 30*F. As the say "it all depends....."

I think the battery is the 185ah, but touted as 400 amps by Roadtrek Northstar TPPL battery.

Here is the generic Northstar TPPL manual. At 32* F they want 15v, it appears, and 14.7v at normal temp.

https://www.batteryplex.com/Sheets/N...ion-Manual.pdf

markopolo · 10-15-2018, 11:17 PM

Quote:

Originally Posted by cruising7388

The Powerstar units have a temperature compensation RJ-11 port but AFAIK, since there may be multiple batteries at different ambient temps because of their different locations, Roadtrek doesn't implement any battery temp sensing probe.............

That's what the manual indicates. I think cruising7388 posted this link the other day: https://www.sigineer.com/wp-content/...-2017-July.pdf

The temperature compensation looks to be more of a safety feature than continuous adjustment. The only details I can find are:

Quote:

When the battery voltage is over 40°C (104°F), it will reduce the charging voltage by 0.1Vdc with every degree of temperature rise.

and

temperarture control.JPG

on page 19.

cruising7388 · 10-16-2018, 02:23 AM

Quote:

Originally Posted by booster

Many chargers that have temp compensation ability but no sensor attached at an input will revert to an internal temp sensor for the compensation, which is certainly better than nothing. It would be interesting to see if that is the case with that charger.

If it's the case with any charger, I think it's a bad design. If the port is not terminated it should default to no temperature compensation. If the charger environment and the battery environment are not at least similar in temperature, the charger temperature compensation could well be in the wrong direction. Our batteries are below chassis while the Powerstar charger is under the power sofa in a fairly confined space. Only rarely will the two ambient temperatures resemble each other.

cruising7388 · 10-16-2018, 04:15 AM

Quote:

Originally Posted by markopolo

That's what the manual indicates. I think cruising7388 posted this link the other day: https://www.sigineer.com/wp-content/...-2017-July.pdf

The temperature compensation looks to be more of a safety feature than continuous adjustment. The only details I can find are:

and

Attachment 6572

on page 19.

LOL! When battery voltage is over 40 deg C, it's time to take cover!

JohnnyFry · 10-16-2018, 03:41 PM

Be very careful about accepting voltage readings at face value, especially when you are discussing differences tn the sub volt range. The meter should have a recent calibration with a recognized standard, in addition there are thermocouple errors to consider when you connect the meter using dissimilar metals with temperature gradients. Small differences to be sure, but you are discussing small voltage differences in the first place.

Yoshimura · 10-19-2018, 12:09 AM

Quote:

Originally Posted by markopolo

That would end up being the same as no temperature compensation if the interior of the van is maintained at say 72F for comfort.

Yoshimura - can you tell us what brand and model # battery you have? It might be easy to lookup the recommended charge profile for the actual battery.

I recall that the 185Ah battery used in the Zion had peculiar charge requirements and maybe yours is the same brand.

There is nothing connected to the RJ-11 port and the van is currently maintained at 70F, so there should be no temperature compensation (if the unit has an internal temperature sensor).

The battery is a 8A31DT and according to its label, the charging requirements are as follow:

Absorption: 14.1 - 14.4
Float: 13.44 - 13.56
Equalize: 14.4 - 14.6

I verified the charger parameters and the battery type is currently set to B-3 - AMG2 (14.6 / 13.7) which is probably too high for this battery. Probably B-2 AMG1 (14.1 / 13.4) would be more appropriate.

By the way, the GU was defective when I took delivery of the van (voltage was at 19.6V!!!) so maybe the high voltage damaged the charger?

I explained the situation to the dealer and he will open a claim.

Yoshimura · 10-19-2018, 12:13 AM

Quote:

Originally Posted by cruising7388

The Powerstar units have a temperature compensation RJ-11 port

You have more information about this? I would really like to have temperature compensation. You have a part number for the sensor?

booster · 10-19-2018, 12:22 AM

I think there is a definite possibility that any 12v electronics connected during the 19+v period could be compromised. I would confirm the voltages you are getting with a second meter to be certain, and if they are bad tell Roadtrek you want a new charger, being sure to mention the high voltage it saw.

cruising7388 · 10-19-2018, 12:39 AM

Quote:

Originally Posted by Yoshimura

You have more information about this? I would really like to have temperature compensation. You have a part number for the sensor?

Page 19 of the owner manual describes and provides a photo of the sensor and cable but doesn't provide a part number. I've emailed Sigineer in China ;for the part number and a source. I'll let you know what I hear back.