BM 1 battery monitor

grafozz

grafozz

Well-Known Member
Joined
11 Jan 2004
Messages
785
Location
kefalonia ,greece
Visit site
Before disconnecting my batteries today ,theBM1 monitor read 100% charged( from solar panels ) after re-connecting them it read 10% charge ! what happened ? another battery volt monitor shows they are fully charged . does the BM1 have no memory ?
 
[ QUOTE ]
...does the BM1 have no memory ?

[/ QUOTE ]Don't think it does - it's intended to be permanently connected to the batteries.
 
According to the operators handbook, if you dissconect the BM-1 from the battery then you need to run a discharge current for a while so it can re-establish itself.
Just switch on a load (a couple of light etc.) and wait a few mins until the % capacity settles. Then you can resume charging. .
 
[ QUOTE ]
[ QUOTE ]
...does the BM1 have no memory ?

[/ QUOTE ]Don't think it does - it's intended to be permanently connected to the batteries.

[/ QUOTE ]
That is correct.
 
Thanks , for the replies ,

ok- so why ,when I do connect it to the fully charged batteries does it read 9% charged ?? -today . is it faulty ?

supposing i had just fitted a new BM1 , with no previous , why would it read such a low battery state ? they are most definitely charged. the boats out on the hard with the solars pumping up the batteries every day .

any more ideas ,please ?
 
crossbones , thanks , I did try firing up both fridges to put it under load but still reading 9%

I will try leaving them on for a while to see if that has any effect , grafozz .
 
i have abandond mine as a reliable source of state of battery and use only to see voltage or amps. A friend suggested using magic marker pen and go over the the bit that tells percentage of battery state. Sorry but I am not impressed with them at all

I have since splashed out and bought a merlin battery monitor that works as it should
 
I don't have the instructions in front of me, but I wonder if having disconnected and reconnected it, is there an initialisation that you have to go through again? Maybe for instance it needs to be told the capacity of your batteries again?
I have had one of these for about 3 years and think it is an excellent piece of kit, but I can't say that I have ever disconnected it..
 
when you connect it, does it show a flashing "charge battery full" indication ?
if so, then you should continue charging the batteries (even on float voltage) and in a matter of minutes it should be calibrated, indicate 100% charge and so on

that is the case with mine anyway ..
 
thanks vic ,
I have the manual , and tried re- setting again today , but it still reads 11% I switched on fridge , lights , but the only change in the reading was from 0.5 amps to 0.4 amps ??? its weird !
 
I have the manual , and tried re- setting again today , but it still reads 11% I switched on fridge , lights , but the only change in the reading was from 0.5 amps to 0.4 amps ??? its weird !
-----------------------------------------------------------------------
Sounds like it's not connected properly. Have a word with nasa, they are usually very helpfull.
 
You must log in or register to reply here.

Share this page

Top