15V 10A Regulated PSU + Kemo M102A splitter

[Refueler]

OK ... this is not an invitation to suggest other items - as I already have these two items ... at present on different installs.

But the thought occurred that the PSU - being regulated at 15V .... the Kemo unit being a charge controller that splits to two batterys as required ... 10A being its spec ...

https://www.amazon.co.uk/M102A-crossover-batteries-separately-alternator/dp/B004AVGSBA

Would it work to maintain two Lead Acids on board while moored and shore power available.

I have smart chargers on board - that usually do kick in when battery level drops - but every so often they don't kick in and when I go on board - I have to cycle the modes to reset them.

If the PSU + Kemo could work .. could be the answer.

Like I say - I already have these and not looking to buy anything instead.

 

[B27]

I can only guess what's in the Kemo unit, the description hints that it needs cooling for high current, which implies voltage drop...
I guess it's got two diodes in it?
It doesn't know whether it's got 6 0r 12 or 24V?
Does that imply no regulation?
Or maybe it senses the battery and regulates?

I think you want to get your 15V down to about 13.6, even at low current.

Given the high price of batteries and the hassle factor, I wouldn't be starting from there when you can get a maintenance charger which works or a regulated supply of the right voltage quite cheaply.

 

[William_H]

The splitter does not indicate it has a low voltage drop when passing current. Presumably then it will drop about .7 volt typical silicon diodes. That will be ideal as 15v will be a bit too high for float battery charge voltage. ie 14.3 should be ok. Check the voltage at the battery after a while of charging. If it does go to 15v I think that a bit too high. In any case check for bubbling of battery electrolyte and loss of electrolyte indicating excessive charge. Even then 14.3 might be too high.
Open up the PSU and hopefully you will find an adjustable resistor to vary (reduce voltage). If that fails then buy 2 more silicon diodes each to go in series with each battery +ve to reduce voltage a further .7volt. Something like this using just 2 diodes. https://www.jaycar.com.au/8a-800v-i...c11edc2&sort=relevance&searchText=power diode. ol'will

 

[Refueler]

OK ..

1. It does not drop 0.7V as in diodes ... the unit I had before only dropped about 0.2 - 0.3v
2. Maintenance charger - cheap ? I have been searching for such .. and as I say - I have so-called already - but they need resetting every so often ..
3. A regulated PSU is the way to go with the splitter - as smart chargers make the splitter shut down.
4. Cooling at 24V ... w hen you see how small the unit is - its no surprise that cooling may be required. Ever felt a 24V charger ? or a 12V at reasonable ampage ?

I agree that 15V may be a bit high ... but PSU's are mostly based on 5V , 6V , 12V , 15V , etc. I cannot recall seeing a 14V version .. and of course I have a 15V unit on my bench.

 

[PaulRainbow]

OK ... this is not an invitation to suggest other items - as I already have these two items ... at present on different installs.

But the thought occurred that the PSU - being regulated at 15V .... the Kemo unit being a charge controller that splits to two batterys as required ... 10A being its spec ...

https://www.amazon.co.uk/M102A-crossover-batteries-separately-alternator/dp/B004AVGSBA

Would it work to maintain two Lead Acids on board while moored and shore power available.

I have smart chargers on board - that usually do kick in when battery level drops - but every so often they don't kick in and when I go on board - I have to cycle the modes to reset them.

If the PSU + Kemo could work .. could be the answer.

Like I say - I already have these and not looking to buy anything instead.

It won't work, unless you want to kill the batteries.

The splitter does just that, splits whatever you feed into it and that's meant to be a regulated alternator current. If you feed 15v into it, it will charge the batteries at 15v, minus the small voltage drop. 14.7v continuous will destroy the batteries in a short time.

 

[B27]

OK ..

1. It does not drop 0.7V as in diodes ... the unit I had before only dropped about 0.2 - 0.3v
2. Maintenance charger - cheap ? I have been searching for such .. and as I say - I have so-called already - but they need resetting every so often ..
3. A regulated PSU is the way to go with the splitter - as smart chargers make the splitter shut down.
4. Cooling at 24V ... w hen you see how small the unit is - its no surprise that cooling may be required. Ever felt a 24V charger ? or a 12V at reasonable ampage ?

I agree that 15V may be a bit high ... but PSU's are mostly based on 5V , 6V , 12V , 15V , etc. I cannot recall seeing a 14V version .. and of course I have a 15V unit on my bench.

There are lots of 13.8V regulated supplies about, they were popular for CB and Ham radio, also built in to many units with sealed lead acid back up batteries, like alarms and emergency lights. 13.8V less a drop of 0.2V should be an acceptable float?
Many 'equipment' PSUs have some adjustment.

A lot of off the shelf psus and regulators are not really intended to have the output powered by a battery when the input isn't powered.

Maybe there's a reason or two behind actual decent battery chargers costing what they do?

 

[rogerthebodger]

I have one of those dual battery regulators on my boat charging 2 separate batteries and powered by a solar panel and had worked OK for 10 years.

I used Kemo single battery regulator for over 15 years without an issue.

They will not fully charge a LA battery but will keep the battery live and keep up with self-discharge

 

[Refueler]

"Maybe there's a reason or two behind actual decent battery chargers costing what they do?"

Have you seen the price of a decent PSU ? I can easily spend similar money on a decent PSU as a decent charger ...

 

[Refueler]

I have one of those dual battery regulators on my boat charging 2 separate batteries and powered by a solar panel and had worked OK for 10 years.

I used Kemo single battery regulator for over 15 years without an issue.

They will not fully charge a LA battery but will keep the battery live and keep up with self-discharge

Thank you RB ...

 

[PaulRainbow]

I have one of those dual battery regulators on my boat charging 2 separate batteries and powered by a solar panel and had worked OK for 10 years.

I used Kemo single battery regulator for over 15 years without an issue.

They will not fully charge a LA battery but will keep the battery live and keep up with self-discharge

Why will they not charge a battery ? Do they regulate the voltage or just split what the input voltage is ?

 

[rogerthebodger]

Why will they not charge a battery ? Do they regulate the voltage or just split what the input voltage is ?

They are a simple on /off regulator that switches off at about 13.6 volts so will prevent over charging but on the downside will not charge fully

M102A Second battery charger 6 - 24 V/DC

This is the single battery regulator similar to the one above but for 2 separate batteries

M149N Solar Charging Controller 12 V/DC, 10 A / 20 A

Thay do charge the battery but only up to the set voltage then shut off unlike a PWM regulator that showily reduce the effective voltage by PWM

 

[PaulRainbow]

They are a simple on /off regulator that switches off at about 13.6 volts so will prevent over charging but on the downside will not charge fully

M102A Second battery charger 6 - 24 V/DC

This is the single battery regulator similar to the one above but for 2 separate batteries

M149N Solar Charging Controller 12 V/DC, 10 A / 20 A

Thay do charge the battery but only up to the set voltage then shut off unlike a PWM regulator that showily reduce the effective voltage by PWM

Gotcha, thanks for the explanation.

 

[William_H]

OK ..

1. It does not drop 0.7V as in diodes ... the unit I had before only dropped about 0.2 - 0.3v
2. Maintenance charger - cheap ? I have been searching for such .. and as I say - I have so-called already - but they need resetting every so often ..
3. A regulated PSU is the way to go with the splitter - as smart chargers make the splitter shut down.
4. Cooling at 24V ... w hen you see how small the unit is - its no surprise that cooling may be required. Ever felt a 24V charger ? or a 12V at reasonable ampage ?

I agree that 15V may be a bit high ... but PSU's are mostly based on 5V , 6V , 12V , 15V , etc. I cannot recall seeing a 14V version .. and of course I have a 15V unit on my bench.

The .2 v drop would be applicable to schotky diode type splitter. In it's intended function less volt drop is desirable. So yes necessary to check voltages in operation. Yes it would be ok to use silicon diodes for volt drop. Being aware that at 10 maps they will dissipate 7watts which will need a heat sink of perhaps 4 square inches of aluminium or similar. it looks like none of my usual sources sell single silicon diode rectifiers with stud mount that were common once. The 4 diode bridge rectifier has 4 diodes wired in a bridge form. (cheap enough) But you can access one or 2 diodes easily. By the time you fit diodes you may as well leave out the splitter you have. Especially if drop is only .2v. You might end up with 3 of those bridge rectifiers. giving 2 diodes in series to each battery. PM me if you choose to go that way and are confused with connections. ol'will