Omc Charging system Vs. AGM Batterys

**olboatman** · 03-05-2017, 08:38 AM

I seem to remember that I read that my 85 V4 charging system is not compatable with AGM batterys. Can anyone help me out with this before I buy one for my Viper?

Thanks Gary

**olboatman** · 03-07-2017, 08:07 AM

ttt Someone

Help!

**powerabout** · 03-07-2017, 08:11 AM

I think no agm was true right up to ficht?

**olboatman** · 03-07-2017, 08:14 AM

Originally Posted by powerabout

I think no agm was true right up to ficht?

Thanks powerabout.....could you explain a bit better for an old man! Gary

**powerabout** · 03-07-2017, 08:25 AM

Something to do with the electronics in the watercooled regulator as prior was no issue
You can get weird issues with some batteries and they wont charge from the engine but all other tests seem ok.
Must be something to do with internal resistance I guess?
I dont actually remember if it was ever explained in a service school

**olboatman** · 03-07-2017, 08:39 AM

Originally Posted by powerabout

Something to do with the electronics in the watercooled regulator as prior was no issue
You can get weird issues with some batteries and they wont charge from the engine but all other tests seem ok.
Must be something to do with internal resistance I guess?
I dont actually remember if it was every explained in a service school

Thank you sir! I will stay away from AGM units then. Gary

**rjdubiel** · 03-07-2017, 01:15 PM

I was told that the motor could overcharge the AGM battery and hurt its ability to keep a full charge. Since they are sealed batteries they cannot be filled again after gassing off or something like that, a standard battery can be filled again when overcharged. I actually got two nice aluminum battery boxes/hold downs from a member here but not sure i am going to go that route either now. One was going to run on my OMC crossflow and the other on my old merc. Anyone have some info that will change my mind?

**olboatman** · 03-07-2017, 03:17 PM

Ya know. Battery Tender makes a Lith Ion battery that is small and light. I will do some research and get back to ya. Gary

**olboatman** · 03-07-2017, 08:07 PM

OK RJ Checked out Battery Tender Lith Ion Batteries and the largest cranking bat that will spin our V4s is about 35 amphrs. I used a small 35 amp bat on my old stock 140 and it did fine.......I dont run any radios etc. It weighs ONLY 3.75 lbs and is 6" x 5" x 4"s in size. The bad news is that it costs about $300 and can only be charged @ a max of 10 amps (how I killed my 35 amp AGM from what I have learned). Do you know what amp our v4s charge at? Just thinkin out loud! Gary

**powerabout** · 03-07-2017, 08:16 PM

V4 9 amp for looper 6 for xflow 10 amp if watercooled reg rec used i seem to remember
Assuming you dont have a vented flywheel??

**olboatman** · 03-07-2017, 08:29 PM

Thanks power......does the vented flywheel charge at a different rate? Gary

**powerabout** · 03-07-2017, 09:50 PM

Originally Posted by olboatman

Thanks power......does the vented flywheel charge at a different rate? Gary

There is a 35amp kit for v4 looper and old crossflowv6 so just checking and they use a different flywheel.
Can you confirm with a few photos of your engine
Also need to see if it has a regulator or not.

**olboatman** · 03-08-2017, 07:50 AM

Originally Posted by powerabout

There is a 35amp kit for v4 looper and old crossflowv6 so just checking and they use a different flywheel.
Can you confirm with a few photos of your engine
Also need to see if it has a regulator or not.

power It is still created as the power head was shipped to me and I will post pics of this project soon. It has the same flywheel and regulater as the stock "85" crossflow 140 I have on my CVX 17. The mota was built for round track racing and talking to the builder he had said it had stock electronics and charging system. I was just curious about the "vented" flywheel. Thanks again Gary

**rjdubiel** · 03-08-2017, 09:40 AM

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I am assuming mine is 9-10 amp, but going V6 this year again on the viper so will keep the interstate green top. Most likely I will need all the cranking power I can get. And the ability to keep cranking when I flood it out on the river or some thing like that far from a charger.

**rjdubiel** · 03-08-2017, 09:53 AM

Does the V6 Crossflow with a non vented wheel, the 10 amp system, charge more than 10 amps when running? Could that be the issue for these AGM batteries?

OPTIMA BLUETOP® CHARGING INFORMATION

The following charging methods are recommended to ensure a long battery life. Always use a voltage-regulated charger, with voltage limits set as described below.
BLUETOP Type: 34M

These batteries are designed for engine starting applications. They are NOT recommended or warranted for use in deep-cycle applications.
Recommended charging information:

Alternator:
- 13.3 to 15.0 volts, no amperage limit.
Battery Charger:
- 13.8 to 15.0 volts, 10 amps maximum, approximately for six to twelve hours.
Rapid Recharge:
- Maximum voltage 15.6 volts (regulated), no current limit as long as battery temperature remains below 125°F (51.7°C). Charge until current drops below one amp.
Float Charge:
- 13.2 to 13.8 volts, one amp maximum current, time indefinite (at lower voltage).
- Strictly adhere to all limits.