Good Sam Club Open Roads Forum: House and Engine Battery -Update 2-Surge? REGEN threat!
Open Roads Forum Already a member? Login here.   If not, Register Today!  |  Help

Newest  |  Active  |  Popular  |  RVing FAQ Forum Rules  |  Forum Posting Help and Support  |  Contact  

Search:   Advanced Search

Search only in Tech Issues

Open Roads Forum  >  Tech Issues

 > House and Engine Battery -Update 2-Surge? REGEN threat!

Reply to Topic  |  Subscribe  |  Print Topic  |  Post New Topic  | 
Page of 5  
Next
BFL13

Victoria, BC

Senior Member

Joined: 02/15/2006

View Profile



Posted: 10/19/20 08:42pm Link  |  Quote  |  Print  |  Notify Moderator

Update 24 Oct, Update 2- 28 Oct

I have not worried before about alternator charging with House and Engine both being flooded or even when I had AGM House and flooded for the Engine.

That included while driving and also while parked where the Engine batt is connected to the House batts and both being floated. (Same with leaving both on the same solar)

However, I am getting an SiO2 battery for the House in the TC, and am nervous about having it in parallel with the very different type of battery for the engine (flooded).

I could disconnect the parallel connection and maintain the Engine battery separately while keeping the solar and House charger just for the House. That would mean no alternator charging even as an emergency method if the House battery got too low. (no gen with the TC)

What are folks with Li batteries (also very different from flooded) for the House doing in this regard? Thanks.

* This post was last edited 10/28/20 10:13am by BFL13 *   View edit history


1. 1991 Oakland 28DB Class C
on Ford E350-460-7.5 Gas EFI
Photo in Profile
2. 1991 Bighorn 9.5ft Truck Camper on 2003 Chev 2500HD 6.0 Gas
See Profile for Electronic set-ups for 1. and 2.

theoldwizard1

SE MI

Senior Member

Joined: 09/07/2010

View Profile


Offline
Posted: 10/19/20 08:46pm Link  |  Quote  |  Print  |  Notify Moderator

What you want is a DC-DC battery charger. Just make sure that one of the supported "battery chemistries" is SiO2.


Hmmm ... Quick search did not turn up such a beast ! Worst case, run a 1000W inverter off of the engine battery and power your SiO2 battery charger. You probably should wire a relay in so that the inverter is only powered when the engine is running.

* This post was edited 10/19/20 08:52pm by theoldwizard1 *

time2roll

Southern California

Senior Member

Joined: 03/21/2005

View Profile



Good Sam RV Club Member


Posted: 10/19/20 08:58pm Link  |  Quote  |  Print  |  Notify Moderator

Still no effect while charging. In use they are separated. No issues.


2001 F150 SuperCrew
2006 Keystone Springdale 249FWBHLS
675w Solar pictures back up

Ed_Gee

Central Oregon coast

Senior Member

Joined: 01/14/2015

View Profile


Offline
Posted: 10/19/20 09:02pm Link  |  Quote  |  Print  |  Notify Moderator

My solution - long:
My Winnebago Fuse on the Ford Transit 350 HD chassis had this issue. The Ford engine alternator uses a new Ford Smart Charge technology to charge the Ford engine battery (2 AGM batteries) . However we Fuse owners have discovered that when the Winnebago Fuse House batteries are connected to the engine alternator system, the Ford Smart Charge regulator never drops charge down from its high 14.7 Volt output level. What this means is that all batteries are constantly being charged high rate for many hours a day while driving. This is a good way to cook and ruin nice AGM batteries, including the Ford chassis batteries. I resolved this issue by adding a simple switch to in the battery solenoid circuit that disconnects the Ford 12 V system totally from the House battery bank when driving. The Ford Smart Charge system now drops down to the 13.7V level as it should when the chassis batteries are full and the House batteries are kept safe - my 200W solar keep them up just fine. Same principle could be applied if one changed out the House batteries to another type.


Ed - on the Central Oregon coast
2018 Winnebago Fuse 23A
Scion xA toad

BFL13

Victoria, BC

Senior Member

Joined: 02/15/2006

View Profile



Posted: 10/19/20 09:07pm Link  |  Quote  |  Print  |  Notify Moderator

Good idea with the inverter! That would work for the emergency case of a low House battery. I did run a test for that some years ago with a 400w inverter (I still have) clamped to the engine batt in the truck (same truck) while idling and it ran the Vector charger (same charger as in the TC now) at 20 amps (which needs 320w, the running watts for that 400w inverter.) So I can just have that 400w inverter along as a back-up.

Still does not answer the issue of the very different batteries in parallel where supposedly nasty current eddies and all that get going and any other weird stuff that could be damaging.

The charging voltages, amps amount, and charging profiles are the same, so they are not an issue---it is just their being in parallel that could be.

BFL13

Victoria, BC

Senior Member

Joined: 02/15/2006

View Profile



Posted: 10/19/20 09:19pm Link  |  Quote  |  Print  |  Notify Moderator

time2roll wrote:

Still no effect while charging. In use they are separated. No issues.


No, they would be in parallel while charging or floating driving or parked. (It is a Chev with Pin 4 always live unless you pull the fuse for that or yank the 7-pin connection out)

There is something about weird things that can happen inside and between dissimilar batteries in parallel that might be more so when the batteries are very different as with Li or Si and "ordinary" flooded or AGM types.

I wonder what the Li guys are doing if anything?

shastagary

minnesota

Senior Member

Joined: 07/16/2007

View Profile


Offline
Posted: 10/19/20 10:29pm Link  |  Quote  |  Print  |  Notify Moderator

if you wanted to keep the ability to charge wit your alternator one of these would do it properly

Victron Energy Orion-Tr Smart 12/12-Volt 18 amp 220-Watt DC-DC Charger

Renogy Board 40A DC to DC Battery Charger Using Multi-stage Charging

MEXICOWANDERER

las peƱas, michoacan, mexico

Senior Member

Joined: 06/01/2007

View Profile


Offline
Posted: 10/19/20 10:30pm Link  |  Quote  |  Print  |  Notify Moderator

I caught the miscommunication BFL. He meant charging no issues, separated (isolated) same thing no issues. The parallel was stopped.

Unless finish charging voltages are different or amperage tolerances are limited, who cares? Certainly not the batteries.

A note too often ommited, is the engine battery suffers extremely high temperatures. Even at 13.4 volts temperature correct for the proper voltage at 125 degrees F and your eyes will open wide.

I hate to think what my bus batteries went through when it got to 122F at Ciudad Obregon, Mex.

You're still on Vancouver Island, right? Battery Paradise.

BFL13

Victoria, BC

Senior Member

Joined: 02/15/2006

View Profile



Posted: 10/19/20 10:44pm Link  |  Quote  |  Print  |  Notify Moderator

Mex, do you mean they can be charged together in parallel no problem, but should not be floated together in parallel or what?

I don't know if there is a threat from eddies and all that or not. Or is it only between flooded batts in parallel and it would not happen at all between an Li and a flooded or an Si and a flooded. Or what? Thanks.

BFL13

Victoria, BC

Senior Member

Joined: 02/15/2006

View Profile



Posted: 10/20/20 11:14am Link  |  Quote  |  Print  |  Notify Moderator

More reading up on the possible threat and it seems mostly for when they are in parallel but not being floated. time2roll has always said in that case the float voltage "floats all boats". The things that happen while being charged can matter, but from the incomplete info I have, are not damaging to the batts as such. Maybe more info on that will appear...

There will be longer times when the unit is parked and not plugged in with little or no solar, so I am just going to pull Stud 1, leave the 7-pin connected, and keep it that way. If the truck battery needs to be floated, I will do that with a separate maintenance charger I have.

That is easiest for my situation. If ever needing an emergency recharge for the House batt, I can put Stud 1 Pin 4 fuse back in or use the inverter method. Either way has the amps under the 25 amp charging limit for my particular House batt .

I don't know what Li guys do, but that's my plan. Ed-Gee's post is very interesting on his situation too.

Reply to Topic  |  Subscribe  |  Print Topic  |  Post New Topic  | 
Page of 5  
Next

Open Roads Forum  >  Tech Issues

 > House and Engine Battery -Update 2-Surge? REGEN threat!
Search:   Advanced Search

Search only in Tech Issues


New posts No new posts
Closed, new posts Closed, no new posts
Moved, new posts Moved, no new posts

Adjust text size:




© 2021 CWI, Inc. © 2021 Good Sam Enterprises, LLC. All Rights Reserved.