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Ensign · 10-05-2006, 11:13 AM

I didn't get any response from the "Problems and Solutions" section so hopefully somebody who frequents the Toy Hauler section can help me.
Last week I installed 6 new Trojan T-105 batteries wired in series/parallel. Now I want to upgrade my converter/battery charger. My question is, what size (amps) should I get? I've pretty much decided I want to go with an Intellipower unit with the Charge Wizard. I currently have a Magnetek 7345 unit.
My total 20 hour amp hour rating is 675 AH.

Using the rule of
Charge Rate = "Capacity"/10 where Capacity is in amp hours I need a charger rated with around 67.5 Amps ( 675/10=67.5). The Intellipower units come in 60 & 80 Amp versions. I am thinking the 80 amp unit would give me maximum charging current when I am plugged into shore power or running my generator. Many time when running the generator there will be other 12v accessories on sucking down my available amps, thus my reasoning for the 80 amp unit.
Assuming my batteries are dead and the converter is putting out it highest voltage (14.4v, 80 amp current), what size wire do I need? Currently I have 6 AWG going from the terminal board almost all the way to the batteries. Right before the batteries there is a circuit breaker and a kill switch where the wire is reduced to 8 AWG. Should I replace this wire with 6 AWG if I get the 80 Amp unit?

Are there any other factors I have not considered?

Larry
2001 Forest River F37 Toy Hauler

Ensign · 10-05-2006, 11:13 AM

I didn't get any response from the "Problems and Solutions" section so hopefully somebody who frequents the Toy Hauler section can help me.
Last week I installed 6 new Trojan T-105 batteries wired in series/parallel. Now I want to upgrade my converter/battery charger. My question is, what size (amps) should I get? I've pretty much decided I want to go with an Intellipower unit with the Charge Wizard. I currently have a Magnetek 7345 unit.
My total 20 hour amp hour rating is 675 AH.

Using the rule of
Charge Rate = "Capacity"/10 where Capacity is in amp hours I need a charger rated with around 67.5 Amps ( 675/10=67.5). The Intellipower units come in 60 & 80 Amp versions. I am thinking the 80 amp unit would give me maximum charging current when I am plugged into shore power or running my generator. Many time when running the generator there will be other 12v accessories on sucking down my available amps, thus my reasoning for the 80 amp unit.
Assuming my batteries are dead and the converter is putting out it highest voltage (14.4v, 80 amp current), what size wire do I need? Currently I have 6 AWG going from the terminal board almost all the way to the batteries. Right before the batteries there is a circuit breaker and a kill switch where the wire is reduced to 8 AWG. Should I replace this wire with 6 AWG if I get the 80 Amp unit?

Are there any other factors I have not considered?

Larry
2001 Forest River F37 Toy Hauler

RustyJC · 10-05-2006, 11:22 AM

Larry,

I've put a short-cut on this thread to the RV Systems and Technologies - RV Systems and Appliances forum as well.

Rusty

diirk · 10-05-2006, 11:52 AM

This might be worth looking onto:
Magnetek Upgrade

Ensign · 10-05-2006, 09:02 PM

Rusty,
Thanks for pointing out the RV systems and Technologies and RV systems and appliances sections. I totally over looked those sections.

Diirk,
Thanks also.
Larry

Gary RVRoamer · 10-06-2006, 04:45 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Are there any other factors I have not considered? </div></BLOCKQUOTE>

The circuit breaker between the charger and the batteries must be able to handle the charge load. There may also be a solenoid & relay in the circuit - they are present in some designs to allow charging source to be switched from the converter/charger to the engine alternator.

I put a 90A Iota charger in mine and found that the controller board in my rig has a 50A breaker. It pops open if the batteries are too far down and they try to suck more than 50A. I also found that the solenoid and relay would stick sometimes after re-charging when the bateries had gotten well discarged. I'm guessing that the high amp load on re-charge may be causing this, but haven't pulled the relay out to see (don't know if I will be able see inside it anyway). If it sticks, I bang on it with a wrench and it usually switches with a "clunk" after a few whacks.

I solved the circuit breaker problem with a bypass swich - a battery switch tha allows me to select Bank 1 or Bank 2. All my batteries are wired in one bank, but I use position one to go through the controller board and circuit breaker (normal operation) and use position two to bypass the controller board and go direct to the batteries. I use that only when I'm recharging after heavy use and need all 90A.

For what its worth, 50A worth of charging is adequate for most occasions. It only takes a little while extra to chage. I use full 90A power only when I'm using the generator to recharge and want to minimize the run time (and noise).

Ensign · 10-06-2006, 07:56 AM

Great input Gary. Thank you so much. I will look to see what Amperage breaker I have and try to identify if I have a Solenoid & Relay in my trailer.

What size wire are you running from the converter/charger to your batteries?

2BlueHeelers · 10-06-2006, 04:48 PM

Go for the upgrade w/ as much amperage as you have space so you can 'properly' charge those 6 T105's. I replaced my Magnacr@p with the intellipower and the difference has been night and day.

Pointers-
-upgrade your breakers to handle the increased load
-upgrade your power wire AND ground to at least 4AWG for the best transfer of current.
-upgrade your battery bypass switch.
Here is a link to my mod Converter upgrade