Charging Voltage Math

[Nesting Zombie]

Hi ya Merl,
Well I would have thought the same as you, That the ‘Bulk’ time of 14.7v at near to full pelt would stay on for longer until Battery is around 80% charged, Then Dropping down on to ‘Absorption’ Still at 14.7 in this case but less & less Current until it’s around 97% full & goes on to ‘Float’ (13.8v) at a trickle to Top off.
But ‘Bulk’ seems to always be around the Minute or 90sec mark irrespective of the hours parked up. & THATS what I don’t understand.

Note, Mo has a pretty consistent & acceptable draw of 1.5 to 2amp per hour running ’Stuff’ aboard 24/7 so that’s anything around the 40amp per 24hr mark.
I’m then Guessing that once I use Lights, Water Pump, Phone Charging it would be around 45amp per any 24hr period aboard normal, Rising to around 50amp if I run the Heater at a guess .

I just don’t understand HOW I can use say 40amp from the battery, Then have 40amp replaced by a 30amp charger in around 40 Minutes

 

[merl]

I just don’t understand HOW I can use say 40amp from the battery, Then have 40amp replaced by a 30amp charger in around 40 Minutes

Simple answer to that is....YOU CANT! so something else is going on.
How old is your battery?
Approximately what is the wiring distance and gauge of cable between the Leisure Battery and the DC-DC charger?

 

[Nesting Zombie]

About 800mm from Starting Batt to Charger, About 800mm from charger to the new 225ah Leasure battery.

All joking aside ive just switched the engine off -

I’ve got Heat, Power, Nothing has failed, it’s all working as it should, I just can’t get my head around the Mathe‘S’ () & that annoyed me.

I think it could be too many ambiguous readings from questionable quality meters, & I should get someone to fit a proper meter & test the system.

 

[colinm]

Despite just getting three electrical answers right on UC I hate trying to remotely diagnose these things.
I'll throw this in, how's your solar connected, if you have it, and could that be interfering with the charging figures.

 

[Nesting Zombie]

Hi ya,
Nope, No Solar fitted

 

[Robmac]

Despite just getting three electrical answers right on UC I hate trying to remotely diagnose these things.
I'll throw this in, how's your solar connected, if you have it, and could that be interfering with the charging figures.

Good wasn't it? I got some of them right tonight but not the electrical ones.

 

[colinm]

Good wasn't it? I got some of them right tonight but not the electrical ones.

I was surprised that they couldn't answer several easy questions, but then if you know the answer it's easy, if you don't it's hard. I was very impressed with the winner of tonight's Mastermind.