Questions for Mitch

justjames

justjames

Adventurist
@Mitch, I've ordered your Group 31 hold down and will go the route of one, upgraded battery in my 2016 Tacoma. I'll be running a fridge, a cpap machine which has about 10ah/night draw and the occasional LED lamp for a couple hours. I typically drive 5-6 hours per day while on a trip and rarely stay in one camp more than one night.

Should I add a DC to DC charger to keep a Group 31 AGM fully charged?

Is solar a better option?

Thanks!
 
You're running a single Group 31 as your only battery?

A DC to DC charger is when you have a dual battery setup.
 
Yes, running a single Group 31 AGM. Will the stock alternator be sufficient or do I need to play with a diode?
 
A Schottky Diode will be fine since it increases voltage only a little bit and won't cause any strange over-volt issues.

https://www.hkbelect.com/products/toyota/

HKB offers a unit that's in a nicer package, except that it's using a solid state silicon diode, the voltage drop will be greater and in turn, the voltage increase will be greater as well.

AGM Batteries typically require a slightly higher charging voltage. Odyssey, as an example, are great w/ 14.8V constant voltage (stay below 15v or risk venting). Your vehicle based electronics will, however, signal an over voltage condition. The Toyota alternators generally output 14.2-14.3V w/ no load.

I just ponied up the money for a 20AH Odyssey Charger. I'd used my BatteryMINDer® Model 2012-AGM for two years w/ decent success, but just wanted something faster.

I don't use a diode, but having a supplemental charger works well for me. All the other folks I know run a single or dual 100w panel on their roof and call it a day. Works great between spring and fall. During the winter they still need to hook it up between trips, but energy requirements drop off significantly since their fridges aren't running a whole lot.
 
Thanks for all the info. I'm in the southeast so solar is not a great alternative here with all the cloudy days. Having said that, all the trips I'm planning for 2019-2020 are from Texas to the Rockies up to Alaska. Perhaps solar should be considered since the prices keep going down and quality seems to be going up.

As to the diode conversation, I didn't follow one of your comments:
kalieaire said:
HKB offers a unit that's in a nicer package, except that it's using a solid state silicon diode, the voltage drop will be greater and in turn, the voltage increase will be greater as well.
Click to expand...

Do you mind explaining that for my feeble mind?

One last question, how do you use the supplemental charger, just plug it in when you have access to shore power?[/QUOTE]
 
justjames said:
Thanks for all the info. I'm in the southeast so solar is not a great alternative here with all the cloudy days. Having said that, all the trips I'm planning for 2019-2020 are from Texas to the Rockies up to Alaska. Perhaps solar should be considered since the prices keep going down and quality seems to be going up.

As to the diode conversation, I didn't follow one of your comments:
Click to expand...

The diode replaces the voltage sensor fuse.

Here's the order of operations:
  • If Voltage Sensor sees voltage =14.2 volts, Keep Steady
  • If Voltage Sensor sees voltage <14.2 volts, Increase Voltage
  • If Voltage Sensor sees voltage >14.2 volts, Decrease Voltage
The Diode introduces a voltage drop in front of the Voltage Sensor resulting in <14.2 volts. This in turn signals the voltage regulator to increase the voltage by the amount of the difference.

Silicon diodes introduce a .6-.7v difference

Schottky diodes introduce a .2v difference

With a .2v voltage drop, the resulting voltage increase would bring the system voltage to 14.4v which is just right. 14.8 and 14.9 is a bit high.
 
All great info from kalieaire.

Leaving it stock, you will never get an AGM to 100% charge. The diodes provide an affordable alternative to buying an upgraded alternator.

Solar is a must in my opinion, and the solution I would use given the information you've provided. A permanent installation would be ideal, but there are great portable "suitcases" available from Renogy.com.

Your battery bracket is on the way! I appreciate your business!
 
There's some good info here. I'd love to throw in a related question if I may . . .

I struggle with the same problems. I recently got some solar and that is an alternative on trips, but I park in a deck during the week. I would really like to start the trip with a full battery, but the only way to do that now is to plug it in before I go. Likewise the battery normally has less than a full charge which I am told hurts its life and capacity.

I have a 1989 Land Cruiser FJ 62, and the voltage is not as high as more modern cars. It never rises above 13.8, and often falls low enough to open the Blue Sea ACR at stop lights (12.75v for 30 seconds). I have been told that the diode trick would be a good step, but I am not enough of an electrician to build from scratch, and I can't find a kit or bolt on application. (the site liked above seems to list everybody but the FJ 60 crowd). I have looked at B2B systems, but hate to spend $300 on a $30 problem.

Any ideas?
 
Mitch said:
All great info from kalieaire.

Leaving it stock, you will never get an AGM to 100% charge. The diodes provide an affordable alternative to buying an upgraded alternator."
Click to expand...
Is there a plug and play diode solution similar to the HKB but using a Schottky diode?

If not, I have another question showing my total lack of knowledge on all things electric and solar. If I mount solar panels on the roof of my camper, can they be configured to charge my battery simultaneously with the alternator while driving or do they only work once stopped?
 
kalieaire said:
A Schottky Diode will be fine since it increases voltage only a little bit and won't cause any strange over-volt issues.

https://www.hkbelect.com/products/toyota/

HKB offers a unit that's in a nicer package, except that it's using a solid state silicon diode, the voltage drop will be greater and in turn, the voltage increase will be greater as well.
Click to expand...

I have not been able to find what fuse to replace on a 2018 Tacoma.

There is no "Alt-S" fuse. Only Zuul.
 
Emailed HKB regarding a schottky diode for my Tacoma. The result was "sorry".
 
You must log in or register to reply here.
Back
Top Bottom