Skip to main content ↑ ↓
Topic: Trickle charge and isolator options (Read 836 times) previous topic - next topic

Trickle charge and isolator options

So I was thinking today as I was driving,why can't we put a fused wire with a diode and a switch between the isolators.  That way during storage, if you are plugged in it will charge the start batteries.
2025 Wanderbox Outpost 32 on F600 Expedition Motorhome
2015 Born Free Royal Splendor on Ford 550 nonslide version  for sale
Former Coaches  covering. 360,000 miles
1999 34 U270
2000 36 U320
2001 42' double slide U320
2018 Jeep Rubicon

Re: Trickle charge and isolator options

Reply #1 –
Would that not be the same as having the boost switch on?
Peter & Beth Martin
No Forrest? What have you done?
MC# 15890 until Dec 2016; FMCA #F329677
Cincinnati, OH

Re: Trickle charge and isolator options

Reply #2 –
A diode would lower the voltage too much. 
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Trickle charge and isolator options

Reply #3 –
Quote from: wolfe10 –
A diode would lower the voltage too much.

Unless it's germanium. There are some fairly substantial germanium diodes out there. I used one as a blocking diode on the sailboat between the solar panels and the batteries. Found it at a surplus electronics outfit in Oakland, CA (which is no longer there).

Craig
1993 U225 36' Unihome GV with PACBRAKE exhaust retarder, Banks Stinger and Solar Panels.
Toad: 1999 Jeep Wrangler 2-door soft-top.

"No one has ever had to evacuate a city because the solar panels broke."

Re: Trickle charge and isolator options

Reply #4 –
We ran with your fused diode idea for over nine years and it kept our start batteries charged. This is the same idea that the very popular Trik-L-Start uses.

We are fine with the diode voltage drop on keeping our start batteries under charge. But with last year's hot summer we noticed that our Xantrex Prosine 2000 was float charging 100 degree batteries around 12.9 volts which is correct for hot batteries. But after diode voltage drop, we were not charging start batteries.

So we purchased, first a Magnum combiner, then BlueSea combiner. We ran each for several months. These smart combiners do not use diodes, so start battery was being charged at house battery voltage, which is a good thing. But because the smart part of the combiners have voltage sensing circuit boards to decide when to close & open relay they were disconnecting just under 13 volts, which did not charge our house battery during hot weather. So we were no better off than using simple diodes. We purchased Trik-L-Start and are back to doing fine again.

We have a switch on the Trik-L-Start to stop combining when we want to remove start battery cables for cleaning, etc. Nice to know that when we remove start battery ground cable that the start battery circuits will be dead. We put the Trik-L-Start, which is water proof on the isolator.

If using a separate start battery charger, it should be temperature compensated to keep start battery from being overcharged in hot temps.

Re: Trickle charge and isolator options

Reply #5 –
Barry,
Did you put the switch in the ground wire of the trickle charge?
Felix and Gail Mathieu
99 U320
Jeep Liberty CRD
Build number 5522

Re: Trickle charge and isolator options

Reply #6 –
John,

I installed a 5A Battery Tender connected to the chassis batteries. The Battery Tender keeps a charging voltage on the house batteries any time 120VAC is available at the outlet into which it is plugged. I installed the small charger over a year ago. I've been pleased with results.
J D Stevens
1997 U295 CAI 36' Build #5085
2002 Subaru Outback
Motorcade 16869
Bellville, TX

Re: Trickle charge and isolator options

Reply #7 –
Thanks guys. Barry,I wondered about the temp issue too.  Might just add a new trickle charge unit. Think the one I had on died.  Will test that tomorrow or later today when I get into Nac. 
2025 Wanderbox Outpost 32 on F600 Expedition Motorhome
2015 Born Free Royal Splendor on Ford 550 nonslide version  for sale
Former Coaches  covering. 360,000 miles
1999 34 U270
2000 36 U320
2001 42' double slide U320
2018 Jeep Rubicon

Re: Trickle charge and isolator options

Reply #8 –
Just replaced echocharger which died with a amp-l-charger, big brother to the trickle charger. It charges chassis batteries up to 15 amps. Works great so far.
Felix and Gail Mathieu
99 U320
Jeep Liberty CRD
Build number 5522

Re: Trickle charge and isolator options

Reply #9 –
That is great I  will look for that.
2025 Wanderbox Outpost 32 on F600 Expedition Motorhome
2015 Born Free Royal Splendor on Ford 550 nonslide version  for sale
Former Coaches  covering. 360,000 miles
1999 34 U270
2000 36 U320
2001 42' double slide U320
2018 Jeep Rubicon

Re: Trickle charge and isolator options

Reply #10 –
Quote from: fjm502 –
Barry,
Did you put the switch in the ground wire of the trickle charge?

Trik-L-Charge has 3 wires, house positive, start positive, ground. The ground wire may only be to light the indicator LED lamp and may not affect charging.

Our charger is connected to isolator terminals, with a switch on the start battery wire.
 

Re: Trickle charge and isolator options

Reply #11 –
Thanks Barry,
Charger is already installed and connected to the isolator terminals.  I have not put in the switch yet.
Felix and Gail Mathieu
99 U320
Jeep Liberty CRD
Build number 5522