Reply
 
Thread Tools Display Modes
 
Old 02-19-2018, 01:48 AM   #1
Platinum Member
 
Join Date: Nov 2014
Posts: 416
Default Hymer new Lithium/AGM combo

Hymer Europe introduced a new energy package that combines Lithium and AGM batteries. Although it has a very limited energy capacity (230 Ah) compared the huge banks some members of this forum have installed in their rigs, it is an original hybrid solution that could be an interesting transition toward the onerous all-Lithium systems. Aren't Tesla cars equiped with an AGM battery to keep the BMS system working?

It is composed of a 95 Ah AGM wired in parallel with a 135 Ah lithium battery.

Is it combining the best of both technologies or simply making it more complicated with limited benefits? Time will tell.


As mentioned in the press release:

...The lithium batteries undertake the majority of the charging cycles, whilst the lead batteries serve as backup storage devices.

…By connecting together two different battery systems, the entire winter-proof system can even be operated at temperatures below 5 C, without any adverse impact on the lithium battery. This is because the operation of the entire system at lower temperatures is ensured by the lead battery, which is impervious to the cold.



The press release:
https://www.eriba.com/assets/files/m...y%20System.pdf

An article in Motorhome Full time
Hymer introduces energy package | Motorhome Full Time











.
__________________

GeorgeB is offline   Reply With Quote
Old 02-19-2018, 02:07 AM   #2
Platinum Member
 
Join Date: Aug 2010
Location: Minnesota
Posts: 6,093
Default

The Roadtrek systems here all have an AGM which is needed to recover the lithiums if they go into shut down. Likely Hymer is using that same thing in Europe, but with a smaller battery.
__________________

booster is online now   Reply With Quote
Old 02-19-2018, 02:23 AM   #3
Platinum Member
 
Join Date: Feb 2016
Location: Portland, Oregon
Posts: 859
Default

Interesting development, seems as Roadtrek influence on Hymer. With a higher sensitivity to gas mileage with EU fuel costs weight savings will have significant value there. Estimated life of 3 years for AGM and 10 years for Li/AGM combo is a little pessimistic for the AGM and optimistic the combo.

No cost data yet, but having a well-engineered system will help to penetrate the market successfully.

For my needs of 230Ah AGM or more weight saving in US is still insufficient to switch.
__________________
George
2013 Sprinter VOILA
https://goo.gl/photos/2NCR3teXLSwNYSwN8
GeorgeRa is offline   Reply With Quote
Old 02-19-2018, 02:34 AM   #4
Platinum Member
 
Join Date: Nov 2014
Posts: 416
Default

Quote:
Originally Posted by GeorgeRa View Post
Interesting development, seems as Roadtrek influence on Hymer. ...
No cost data yet, but having a well-engineered system will help to penetrate the market successfully.
Yes I'm curious if Roadtrek had any input on this European option. Just hope they didn't consult the same engineers. :-0 The Hymer system is offered as a 3000 € option.

The originality of the system seems to be that the two batteries are wired in parallel and are working together to supply power. What kind of hybrid BMS could manage both types?
GeorgeB is offline   Reply With Quote
Old 02-19-2018, 02:37 AM   #5
Platinum Member
 
Join Date: Aug 2010
Location: Minnesota
Posts: 6,093
Default

Quote:
Originally Posted by GeorgeB View Post
Yes I'm curious if Roadtrek had any input on this European option. Just hope they didn't consult the same engineers. :-0 The Hymer system is offered as an 3000 option.

The originality of the system seems to be that the two batteries are wired in parallel and are working together to supply power. What kind of hybrid BMS could manage both types?
The parallel of the battery types has been an issue here with Roadtrek systems from what I have heard. The AGMs can have very short life in them and need replacing nearly every year in some of the examples I have seen mentioned.
booster is online now   Reply With Quote
Old 02-19-2018, 02:26 PM   #6
Platinum Member
 
Join Date: Mar 2014
Location: Herndon, Virginia
Posts: 165
Default

That fact in itself is discouraging and inflates the cost of operation for an already expensive system, as well as adding to the overall weight of the system. It appears that some of the other Li systems out there do not need an auxiliary AGM so apparently it is an issue with the BMS used by Roadtrek (and now, apparently, Hymer). This aspect certainly bears watching.
JohnnyFry is offline   Reply With Quote
Old 02-19-2018, 02:58 PM   #7
Platinum Member
 
Join Date: Aug 2010
Location: Minnesota
Posts: 6,093
Default

Quote:
Originally Posted by JohnnyFry View Post
That fact in itself is discouraging and inflates the cost of operation for an already expensive system, as well as adding to the overall weight of the system. It appears that some of the other Li systems out there do not need an auxiliary AGM so apparently it is an issue with the BMS used by Roadtrek (and now, apparently, Hymer). This aspect certainly bears watching.
We don't know about the new Xantrex system or the Volta system yet, but best guess is that they don't use an AGM.

As far as I have been able to determine, the AGM is only really needed if the BMS has shut the charging down due to under 32*F and there is no way to heat the batteries back up until they will accept charge. ARV doesn't have the AGM, and they are OK if there is still enough charge in the batteries to run the heaters and heat up the batteries until they come back online, but if they are in cold shut down for charging and low battery shutdown you are out of luck and need to get the van to someplace warm. The heaters won't work because none of the charging sources will activate and hold hold voltage without a battery reference. Roadtrek had similar problems before they added the AGM, which allows the charging sources to come on and run the heaters.

IMO, the obvious solution is to make sure there is another way to heat the batteries without going south or inside. The van power system is totally separate and will work normally through all of this, so it seems that all you would need would to be able to switch the heaters to van power until the batteries warm up and a charging source comes on. Unless I am missing something, I just don't see the need for the AGM if you have well designed system.

There is also likely another reason the Roadtrek had to go with the separate AGM, which is not disconnected when the lithium modules are, and that is their horrendously large parasitic losses in lithium modules. They will drain themselves with no loads in only a couple of days, so whenever not being used or able to be recharged, they have to be shut off, and that would mean the charging sources would not activate and the heaters would not work.
booster is online now   Reply With Quote
Old 02-19-2018, 03:28 PM   #8
Site Team
 
avanti's Avatar
 
Join Date: Jul 2013
Posts: 2,487
Default

If I were designing a DIY Lithium system today, I would take a close look at using a small Espar hydronic system as a cold weather backup. I could imagine a well-insulated battery compartment that also housed the expansion tank for the Espar. That way, there would be a lot of thermal mass to minimize cycling of the Espar. In the grand order of things, such a setup would not be all that expensive.

I am, of course, just making all of this up.
__________________
Formerly: 2005 Airstream Interstate (Sprinter 2500 T1N)
Now!: 2014 Great West Vans Legend SE (Sprinter 3500 NCV3 I4)
avanti is offline   Reply With Quote
Old 02-19-2018, 03:28 PM   #9
Platinum Member
 
Join Date: Feb 2015
Posts: 828
Default

Quote:
Originally Posted by booster View Post
The parallel of the battery types has been an issue here with Roadtrek systems from what I have heard. The AGMs can have very short life in them and need replacing nearly every year in some of the examples I have seen mentioned.
I am on three Facebook pages for Roadtrek/Hymer owners and no one has reported having to replace the AGM that works with the lithiums. Many of the owners don't even know that it is there.

Many issues with Promaster starting batteries, but that is a whole different issue that Dodge dealers having been handling.
__________________
Mumkin
2019 Roadtrek Simplicity SRT (almost a Zion)
2015 Roadtrek 170
2011 LTV Libero
2004 GWV Classic Supreme
mumkin is offline   Reply With Quote
Old 02-19-2018, 03:37 PM   #10
Platinum Member
 
Join Date: Aug 2010
Location: Minnesota
Posts: 6,093
Default

Quote:
Originally Posted by avanti View Post
If I were designing a DIY Lithium system today, I would take a close look at using a small Espar hydronic system as a cold weather backup. I could imagine a well-insulated battery compartment that also housed the expansion tank for the Espar. That way, there would be a lot of thermal mass to minimize cycling of the Espar. In the grand order of things, such a setup would not be all that expensive.

I am, of course, just making all of this up.
Those of us that are old enough and live in the cold still remember the gasoline fired engine block tank heaters. They were passive pump "tank" heaters in the terminology of the day and actually worked quite well as long as you kept the exhaust from melting things under the hood.
__________________

booster is online now   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


» Featured Campgrounds

Reviews provided by

Powered by vBadvanced CMPS v3.2.3

All times are GMT. The time now is 02:00 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2018, vBulletin Solutions, Inc.