Lithium Battery test

[Urlauber]

Considering the purchase of one of the Hymer things with EcoTrek 400. Batteries seem to be discharged, even driving the rig for a while doesn't do anything. Seller promises to charge them up.

How would you go about testing if the batteries are any good, i.e. can store and deliver about 400 Ah?
Is there a quick/easy way to do this? I suppose charging them up and putting a load on them. Preferably something static, DC? Air Condition runs through the inverter, plus it cycles on and off. Or boil something for a while on the induction stove? There must be an easier way...

[markopolo]

1500 Watt space heater set to max temperature / 13 volts DC = 115 amps

115 amps * 3 hours = 345 amp hours

2 heaters would halve the time but would be a 3000 watt load. Does it have a 3000W capable inverter?

[DUTCH in Atlanta]

If driving the coach doesn't deliver even a little bit to the battery charge, I would be concerned that something isn't right.

[Rockwood27]

Don't forget that Hymer went out of business, so factory support is nonexistent.

[Urlauber]

Originally Posted by markopolo

1500 Watt space heater set to max temperature / 13 volts DC = 115 amps

115 amps * 3 hours = 345 amp hours

2 heaters would halve the time but would be a 3000 watt load. Does it have a 3000W capable inverter?

Thanks MP, that sounds simple enough. The inverter I believe is 2000W, so a 1500W heater should work. There are some losses due to the inverter inverting, not sure how much, maybe between 20 and 50W?

I wonder if adding a 1500W heater would trip a breaker though...

[markopolo]

120V AC circuits in the van will have a 15A or 20A circuit breaker.


15A x 120V = 1800 Watts so running a 1500W heater shouldn't be a problem.

[Urlauber]

Originally Posted by DUTCH in Atlanta

If driving the coach doesn't deliver even a little bit to the battery charge, I would be concerned that something isn't right.

I am concerned... that's why the question.
If this would happen to me (reviving the batteries) I would be totally screwed... I think. That's why I want to make sure they are not damaged.

[W9TR]

There is a wealth of EcoTrek info on the Hymer Aktiv Owners and Wannabe's FB page. Basically all these came from the factory needing modification of the shore power and underhood generator wiring to eliminate safety and problematic battery management issues.

To check out the whole system you would need a good DC voltmeter and DC clamp on ammeter. You can then determine if the underhood generator is charging the batteries, that the shore power converter is charging the batteries properly, and that the onboard inverter is operating correctly. The advice to check the battery capacity with a heater is spot on - but only after you have verified that the batteries are fully charged.

Given the number of unsold 2019 Actives in dealer inventory, even if the batteries are toast one of these might still be a great deal if you are handy.

[Boats]

There is a couple of YouTube channels that are still active from Roadtrek that are great tutorials for operating the ecotrek system Roadtrekmotorhomes, and Hymer, these are very informative and helped us out a lot. We have a 2017 Agile Sprinter that we love and use every day we have off from Spring to when the snow flies and have never had a bit of problem with the ecotrek system, its worked amazingly well, you might hear different on the forums but I've talked to many people out camping with Roadtreks/ecotrek and have the same opinion as we do, so I guess the take away is know your system, know how to operate it and how it operates.
One of the things that I have to remember every year we take it out if winter storage is that it won't charge unless you turn the system on, you have to press the round rocker switches AND the reset switches above it to turn the system on before it will charge, you can turn on each bank with each set of switches depending on how many you have, either with shore power, underhood generator or solar...simple but easy to forget.
Also the new owners of Roadtrek (Rapido) have started manufacturing and are still using the ecotrek system and have a parts supply left over from the old Roadtrek, that may help too.

[nebulight]

Don't forget to factor in inverter losses. Roadtrek used pretty lousy inverters so expect about 85-88% efficiency. 1500 / 12.8 x 1.15 = 134.76ah. If you get 2.5 hours into the test I'd say you'll be fine as I don't think the BMS will allow you to pull all 400ah of the cells.