Yamaha Crank/House battery charging with supplied harness or VSR/ACR

[fairdeal]

So does the 1 - 2 switches allow each engine to be started from either start battery? I guess adding an emergency parallel switch would improve this option further?

That switch arrangement allows:
- each engine to use its own battery only
- both engines to use either battery 'together'
- both engines to use both batteries 'together' (thus no need for an "emergency parallel" switch)

[boscoe99]

Firstly, thanks all for the advice, I'm definitely learning a lot.

Could undervoltage lockout occur (below definition is taken from bluesea website)? I guess if the alternator output is good enough to stop this from happening then not an issue, although as it stands only 1 engine is charging the house battery, which could pose an issue for me

• What does “Undervoltage Lockout” mean?
  As a safety feature, some ACRs prevent combining into a severely discharged battery. A dual-sensing ACR will monitor the voltage on both batteries and will not connect if either battery is below the undervoltage lockout level. Use caution when combining into a battery with extremely low voltage, because this might represent a faulty battery or a problem elsewhere in the system.

First I have heard of Undervoltage Lockout. I will consult with Yandina, a distributor of ACR's and such, to see if their device (known as a Battery Combiner) has this feature.

[Keithbaja]

WEll, there is many, many reasons on the small vessels we deal with here. 1St of its not really a 12 volt battery. Fully charged is 12.6. Minimum charging is 13.8. Floating maintenance is 13.2. To faildeal there are many reasons to keep your batts on a Small vessel the same group size and manufacture. Rate of discharge. (ROD) depth of discharge (Dod) absorption factor
charging factor and such. If u have the time you can look up ABYC standards.. When I get time I will post a article or to so that all will have a better comprehensive on such matters. FUNNY, I work for soo many electricians on their boats, RVs, offgrid systems. Its crazy
Last yr on dodge c*****n I found and fixed a problem with the instrument cluster shorting out all day long. Fixed in under 10 mins. Guy was impressed, said do u know what I do for a living ? Me, no.

Him,, I'm the head electrician at the San Jose airport can

[boscoe99]

First I have heard of Undervoltage Lockout. I will consult with Yandina, a distributor of ACR's and such, to see if their device (known as a Battery Combiner) has this feature.

Here in Yandina's reply about their Combiner. Their name for an ACR/VSR.

"It has a low voltage lockout that disconnects if both batteries are low. It is set to around 10.8 volts and the red LED will turn on to indicate low voltage lockout.
If only one battery is low it will cycle on and off to add around 1 amp-hour of charge per minute to attempt to revive the dead battery and provide a recovery method. As the dead battery recovers the "on" time will get longer until it stays on if the battery recovers."

The second sentence is what I usually saw with my Combiner. It would cycle for a minute or so until the house battery voltage got close to the starting battery voltage. Then the Combiner would stay connected. Or engaged. Now this was seen with my Mercury outboard motor and then my Yamaha outboard motor. Both of which don't have a lot of electrical power output. If the Combiner is used to parallel two batteries that are being charged by say a 100 amp alternator, the Combiner would not cycle. There is enough electrical power available that can supply the needed current while maintaining the voltage.

[Keithbaja]

Fair deal, my reply to you is right above boscoes

[99yam40]

station batteries I have dealt with in chemical plants for backup power for process and switchgear during power outages had lead calcium and maybe some just lead acid cells.
those different cells had different float and charge voltages.
But with the batteries I have seen on boats I am not usure if any of them have different specs for float and charging voltages.

Is this the reason some say not to parallel different batteries?
do they really have different specs for charging and float?

maybe gel cells would be different?

[boscoe99]

station batteries I have dealt with in chemical plants for backup power for process and switchgear during power outages had lead calcium and maybe some just lead acid cells.
those different cells had different float and charge voltages.
But with the batteries I have seen on boats I am not usure if any of them have different specs for float and charging voltages.

Is this the reason some say not to parallel different batteries?
do they really have different specs for charging and float?

maybe gel cells would be different?

Yamaha approves flooded lead acid batteries, gel lead acid batteries and AGM lead acid batteries for use with their motors. There is no adjustment on the motor to change the output voltage or profile for the different kinds of batteries. They all get the same alternator output. A more or less constant 14.4 volts.

Oh, same with my truck. Just a simple constant voltage output from the alternator. Nothing special about it.

[99yam40]

I just looked at some smaller 12 volt gel cell sealed batteries I have,
one 7AH has specs on the label
Cycle use 14.4V - 15.0V
Standby 13.5 V- 13.8V
Maximum Charging current 2.1 A

I would think too much current flow into the sealed batteries could cause too much pressure build up inside

I am not sure if you could find the charging specs on the boat batteries

but finding specs listed for the batteries you will install, and tie together would be a good idea in case they are different enough to make it a problem

I just bought a new 12V lawn mower battery yesterday, the old one was only showing 7 volts.
I removed the sticker on it and removed the plugs on each cell ( Sticker said do not add water)
levels were very low, so I added distilled water to each cell and tried to charge the battery,

Should have added water a long time ago.

voltage only came up to 8 volts after letting it sit overnight after getting it up to 13.5 volts with my little charger for some hours, battery go very warm with only 4 amps going into it
it was too late for that battery.

[boscoe99]

I just looked at some smaller 12 volt gel cell sealed batteries I have,
one 7AH has specs on the label
Cycle use 14.4V - 15.0V
Standby 13.5 V- 13.8V
Maximum Charging current 2.1 A

I would think too much current flow into the sealed batteries could cause too much pressure build up inside

I am not sure if you could find the charging specs on the boat batteries

but finding specs listed for the batteries you will install, and tie together would be a good idea in case they are different enough to make it a problem

I just bought a new 12V lawn mower battery yesterday, the old one was only showing 7 volts.
I removed the sticker on it and removed the plugs on each cell ( Sticker said do not add water)
levels were very low, so I added distilled water to each cell and tried to charge the battery,

Should have added water a long time ago.

voltage only came up to 8 volts after letting it sit overnight after getting it up to 13.5 volts with my little charger for some hours, battery go very warm with only 4 amps going into it
it was too late for that battery.

I see that similar thing on many batteries. But using a constant voltage charger I have no control over the current. The current flow is what it is.

Maybe they are referring to the use of a constant current charging device.

My small lithium battery will draw more than rated current but the BMS will then turn off the battery. It will come back on. Process is repeated several times until the input current is below some threshold in the BMS. Battery app says that the battery is 100% healthy. BMS is doing its job.

[pstephens46]

I miss Rodbolt. His stand-in is not cutting the cake.