Odyssey Batteries - How to Charge? Diode or DC DC Charger?

[Markuson]

Please update with your experience once you've done this mod. Very curious but very uncomfortable with anything electrical. That said, this so far sounds like it makes sense. Don't want my expensive AGMs to go mammary skyward early if I can prevent it.

I will. Not delivered yet. Shipped from Australia Dec 30... ?

 

[Atwalz]

I ordered three, one for each rig. Stock charges at 13.6v at idle.

 

[RET2]

I will. Not delivered yet. Shipped from Australia Dec 30... ?

For the measly cost of a Big Gulp I would offer my opinions and directions should you require them ROFL

 

[619TOY]

Why do I always feel like the last one to the party? Sorry about that... Assuming you have access to the parts, you can make one of these adapters in about 15 minutes. That said, I know do it yourselfing something like this isn't for everyone but I wanted to do a quick "how to" for anyone interested: I started with a 30 amp factory type fuse as I wanted the filament portion to be as robust as possible for soldering to. I whittled away a little of the plastic case and soldered in my fuse holder and diode. The orientation of the diode is critical and the band of the diode should be closest to the front of the vehicle/fuse to work correctly. Here are a few progress pics:

 

[619TOY]

Results battery at rest:

Factory Charge voltage at idle:

After diode added:

 

[RET2]

Thanks Steve!! What rating was the diode? Good rainy day project for tomorrow I think

 

[619TOY]

I just used a common 3A diode. I considered measuring the actual current first, which is probably next to nothing so I could use a 1A diode, but I was lazy haha...

 

[Markuson]

I will. Not delivered yet. Shipped from Australia Dec 30... ?

Well HOT DOG!

I swapped my Australian Fuse with resistor in just now, and BOOM!

My IBS monitor makes it easy to see the difference immediately, since it has a built-in charge monitor.
Although it's just a range indicator (13.0v, 13.5, 14.0, 14.5 actively indicated)...
...it IMMEDIATELY showed a jump from it's typical 13.5 or 14.0 range when revved to 1500RPMs....right up to the 14.5 range. Note the 14.5 red indicator in the lower left of IBS photo. It NEVER reached this range until now.

This still won’t charge batteries independently, but at least my AGMs are getting the V.

The swap couldn't be easier. You literally just yank the existing 5A fuse from the Alt-S slot under the hood...and pop in the replacement.

It comes with detailed instructions on how to make sure polarity is correct...but you basically just put it in and check for a lit charge light on the dash. If it stays lit...reverse it in the socket and all good.

And ya, one might build one for less, but this fuse adds zero wires or size. Looks just like the normal fuse, with no protrusions of wires raising up into the fuse box.

Super clean manufacture:
HKB Electronics

 

[TonyP]

Someone can have mine when I get my Redarc system.

 

[RET2]

Well HOT DOG!

I swapped my Australian Fuse with resistor in just now, and BOOM!

My IBS monitor makes it easy to see the difference immediately, since it has a built-in charge monitor.
Although it's just a range indicator (13.0v, 13.5, 14.0, 14.5 actively indicated)...
...it IMMEDIATELY showed a jump from it's typical 13.5 or 14.0 range when revved to 1500RPMs....right up to the 14.5 range. Note the 14.5 red indicator in the lower left of IBS photo. It NEVER reached this range until now.

This still won’t charge batteries independently, but at least my AGMs are getting the V.

View attachment 1607390

The swap couldn't be easier. You literally just yank the existing 5A fuse from the Alt-S slot under the hood...and pop in the replacement.

It comes with detailed instructions on how to make sure polarity is correct...but you basically just put it in and check for a lit charge light on the dash. If it stays lit...reverse it in the socket and all good.

And ya, one might build one for less, but this fuse adds zero wires or size. Looks just like the normal fuse, with no protrusions of wires raising up into the fuse box.

Super clean manufacture:
HKB Electronics

View attachment 1607391

So I don't get the Big Gulp?

 

[Markuson]

So I don't get the Big Gulp?

You deserve a Big Gulp anyway, Ralph.

 

[9780LC]

Someone can have mine when I get my Redarc system.

I expect to see a lithium aux battery connected to the Redarc too. Are you looking at them? There are so many to choose from now. When my Odyssey dies I'm getting, I hope a Redarc bms30 (US version) and lithium power.

 

[mark71]

So my question to the people on this forum with knowledge of electronics: is there any chance this will damage other electronics in the car? Higher voltage potentially hard on computers?

Forgive my ignorance.

 

[Markuson]

So my question to the people on this forum with knowledge of electronics: is there any chance this will damage other electronics in the car? Higher voltage potentially hard on computers?

Forgive my ignorance.

My understanding (gurus can correct me...) :

All it's doing is making the alternator think the battery's charge is lower than it actually is. This prompts the alternator to put out a higher voltage (like .5V more) as it would to a low battery. Higher charge voltage is what AGM batteries need anyway...so this helps with that.

It has no effect on anything else.

 

[TonyP]

I expect to see a lithium aux battery connected to the Redarc too. Are you looking at them? There are so many to choose from now. When my Odyssey dies I'm getting, I hope a Redarc bms30 (US version) and lithium power.

I'm VERY tempted. The cost of entry is tough to handle though. A 55ah battery which would replace my 110ah AGM but provide the same power, is about $600. But if I'm going lithium I'd want the same group 35 size which would cost well over $1200... for a 100ah battery. Granted, that's twice the usable power. We'll see.

 

[9780LC]

I've seen group 34 size lithium batteries producing 335ah that cost $1,500 and good to 8000 to 10,000 charging cycles. Never have to be concerned about power again especially because almost all of those amp hours are usable. Looking forward to it.

 

[TonyP]

I've seen group 34 size lithium batteries producing 335ah that cost $1,500 and good to 8000 to 10,000 charging cycles. Never have to be concerned about power again especially because almost all of those amp hours are usable. Looking forward to it.

Do you have a link?

 

[RET2]

It would seem to be an easy fix to just limit what we retro install to fit to work with OEM electrical output. But then what fun would that be?

 

[Taco2Cruiser]

My understanding (gurus can correct me...) :

All it's doing is making the alternator think the battery's charge is lower than it actually is. This prompts the alternator to put out a higher voltage (like .5V more) as it would to a low battery. Higher charge voltage is what AGM batteries need anyway...so this helps with that.

It has no effect on anything else.

Correct, only the battery itself receives an increase voltage. I spent an afternoon with the FSM making sure everything else was still in correct range.

 

[9780LC]

Do you have a link?

This is the one I've been looking at.....it's out of stock right now. They just hit the market and sold out quick.

XS Power XS15K 12V BCI Group 34 Lithium Battery