Reply
 
Thread Tools Display Modes
 
Old 11-27-2018, 11:32 PM   #1
Platinum Member
 
Join Date: Dec 2015
Location: Arizona, Tempe
Posts: 567
Default 2003 Roadtrek hybrid battery system

More parts yet to arrive but the location for the A-B-Both switch (left of refrigerator, right of access door to water valve and water heater)and the 100 amp hour lithium battery (aft of fender well, driver's side, behind inside access door) Expect to put lithium charger in there, too. Haven't located the DC to DC charger yet. There is room behind the A-B switch but not comfortable putting it in with the water system.

Expect we will forego a dedicated lead acid charger for space reasons and use the DC to DC charger, solar, isolator or the converter.

Battleborn sold the 100 amp hour lithium battery yesterday for $849 so decided to get started.

We have found that a 50 amp circuit breaker connected between the lithium battery and the Kisae charger keeps popping even though Kisae specs a 30 amp breaker. We don't have the instrumentation to figure that out but a 100 amp one seems to work. Obviously a current spike, but why.

We will do the parallel hybrid battery testing as soon as I get the class C back from the shop. (Deer strike) I expect a switchable system to be better than a parallel system but we will see when someone puts one together with more fancy circuitry than I have. A no user input system would be nice.
Harry
__________________

hbn7hj is offline   Reply With Quote
Old 12-17-2018, 03:07 AM   #2
Platinum Member
 
Join Date: Dec 2015
Location: Arizona, Tempe
Posts: 567
Default

There is no indication that anyone else is putting in a hybrid battery system but in completing such in the Roadtrek I have made an observation. A fifty amp capable DC switch between the lithium battery and the DC to DC charger is not necessary.

The Kisae DMT1230 charger will not charge the lead acid battery till 12 volts is applied to the control input. The lithium battery can be connected directly to the charger. A switch with minimal current capability is connected between the control input and 12 volts.

Will post the performance of the system when the final connections are made, probably next week. This will essentially triple my battery capacity. I would put in a second lithium battery when/if I go to a compressor fridge.
__________________

hbn7hj is offline   Reply With Quote
Old 12-17-2018, 02:50 PM   #3
Platinum Member
 
Phoebe3's Avatar
 
Join Date: May 2017
Location: California
Posts: 674
Default

Quote:
Originally Posted by hbn7hj View Post
Will post the performance of the system when the final connections are made, probably next week. This will essentially triple my battery capacity. I would put in a second lithium battery when/if I go to a compressor fridge.
Thank you for continuing to keep us updated. I'm not ready or capable of fooling around with our battery systems yet, but I'm still pretty interested in your experiments because I hope to someday take advantage of your results.
__________________
2018 Coachmen Crossfit/Beyond
Phoebe3 is offline   Reply With Quote
Old 12-18-2018, 03:23 PM   #4
Platinum Member
 
Join Date: Dec 2015
Location: Arizona, Tempe
Posts: 567
Default

Thanks for the note. I will confess I don't understand the lack of interest. It works so very, very well. The AGM battery box is not heated so it may as well carry AGM batteries. Adding lithium inside is perfect for them and charging AGMs from the lithium with the DC to DC charger reduces generator charging time by at least 3/4. Solar works better, too. Being able to always use the top 20% of the AGMs, rain or shine, is a plus and keeps them healthy.

We discussed this before and decided many don't understand the importance of keeping the AGMs at 100% daily, some don't like the complexity (grandma can't run it) and the cost of a lithium battery is considerable.

Power is no longer a problem for me. With charge rates up to 130 amps you can always top up before quiet time.

We keep looking for a fire hazard. There doesn't seem to be one with flooded batteries but AGM may be different so be careful.
Harry
hbn7hj is offline   Reply With Quote
Old 12-18-2018, 03:27 PM   #5
Site Team
 
avanti's Avatar
 
Join Date: Jul 2013
Posts: 3,267
Default

I wouldn't interpret lack of action as lack of interest. I think that the rather small population of people who would feel qualified to attempt such a project mostly already have solutions that are "good enough" not to be immediately discarded for such an improvement.

I, at least, have tucked your very interesting project away for future reference.

Thanks for the effort and for taking the time to report.
__________________
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 12-18-2018, 04:08 PM   #6
Bud
Platinum Member
 
Join Date: May 2016
Location: LA
Posts: 840
Default

"I wouldn't interpret lack of action as lack of interest."

Agree, and thanks for posting and posting all of the updates, but........ This has occurred over time and not a couple of weeks. You could post sort of a:

-summary of what is involved
-the application(s)
-pros and cons compared to the conventional lithium or lead-acid solutions

might even assist someone, somewhere in the Hymer Euro-land
Bud is offline   Reply With Quote
Old 12-18-2018, 05:40 PM   #7
Platinum Member
 
Join Date: Oct 2010
Location: VA
Posts: 477
Default

I have followed with interest. My present electrical system is adequate but if I get a compressor fridge I will need more power available. Please continue to post your progress, as it is a great asset to this site.
peteco is offline   Reply With Quote
Old 12-19-2018, 03:58 AM   #8
Platinum Member
 
Join Date: Dec 2015
Location: Arizona, Tempe
Posts: 567
Default

May as well have the discussion here.

Lithium is a better battery than lead acid. It charges like adding fuel to a fuel tank: the same rate till full. A full lithium system would be the best except for the temperature problem. Victron sells a 200ah full lithium system for $7k. I don't know where all the money goes but you can build your own 200ah system using the batteries with the built in BMS for ~$2k.

The only advantage of a hybrid system, which someone else mentioned, is startup of a cold soaked RV (15F?). Turn on the AGM system and warm the place up then lithiums are good to go. You can add lithiums, as we are doing, for 1/3 the cost of a Victron system or an AM Solar sold system.

In a temperate time of the year leave the switch on lithium and keep your AGMs at 100%. It certainly won't hurt them and the complexity is gone.

Camping with a low of 12F I will go through the night on lithium leaving the AGM at 100% to start the generator in the morning. Starting a generator at 12F is not a sure thing and takes a few starts and a bit of battery to get it warm enough to run. The auto choke comes off too early and the thing putt putts until it warms up a bit. Last time it took six starts to get it warm enough to run.

AGM to me means flooded lead acid. AGM is easier to write.

The advantage to us is that our coaches already have the AGM system in a non temperature controlled area so why leave it empty. Heating pads, to me, are not a viable option.
Harry
hbn7hj is offline   Reply With Quote
Old 12-19-2018, 02:04 PM   #9
Site Team
 
avanti's Avatar
 
Join Date: Jul 2013
Posts: 3,267
Default

Quote:
Originally Posted by hbn7hj View Post
AGM to me means flooded lead acid. AGM is easier to write.
AGM does NOT mean "flooded lead acid". The two are disjoint. AGM batteries are a species of Valve-Regulated Lead-Acid (VRLA) batteries. They are not "flooded"--there is no liquid electrolyte present in VRLA batteries, and they have significantly different characteristics.

I am not trying to be pedantic, but we don't want to confuse people.
Quote:
Heating pads, to me, are not a viable option.
Why is that?
__________________
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 12-19-2018, 02:19 PM   #10
Platinum Member
 
Join Date: Dec 2015
Location: Arizona, Tempe
Posts: 567
Default

"Heating pads are not a viable option"

"Why is that?"

Waste of energy and we have so little. Were we talking of 800ah systems it would be different, I think.

I'll take your admonition. And use the terms flooded or flooded lead acid to describe the batteries I have.
__________________

hbn7hj is offline   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 11:02 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2019, vBulletin Solutions, Inc.