Battery charging

[pmagowan]

I Have a CTEK m200 battery charger plugged into the house 110ah battery. The start battery is connected via a BEP VSR cluster. Do I need to switch the emergency parallel on to charge both? Probably a silly question and I probably knew the answer but just got 2 new batteries and the house is reading 13v whereas the start is reading 12.2v.

 

[Rigger Mortice]

Dunno, but, if it were me, with new batteries I would be inclined to charge them separately. That way the charger can do it's best for each battery; if they are both connected at the same time the charger will not be able to optimise the different phases for both batteries. If you connect them now the charger will not be "reading" a 13 volt battery, or a 12.2 volt battery. It will think it is connected to a 12.6 (?) volt or thereabouts battery.

 

[pmagowan]

The problem is it is not set up for easy disconnection and reconnection. I don't really understand the gubbins inside but my theory was that it would power all house functions when we are plugged in and that the engine battery would be taken care of by the alternator. The problem is the battery from halfords is not fully charged at 12.2 and so I would like to 'boost' it without using the engine all day. I don't know if the VSR works backwards as I think it's purpose is to make sure the start battery is charged first and then the house.

 

[Rigger Mortice]

Just disconnect one of the terminals from the starter battery and bung the charger on. It may mean a little fiddling but at least you will be certain that its had the best charge it can get.

Heaven knows what effect, if any, the VSR will have on the charger but, as you've got an intelligent charger, you may as well let it do its best for a new battery.

 

[ghostlymoron]

The spec for your charger says 'Battery capacity 28-300Ah, up to 500Ah for maintenance' so it should be OK to charge both batteries at once. Just switch the cluster to parallel as you suggest.

 

[Stemar]

The spec for your charger says 'Battery capacity 28-300Ah, up to 500Ah for maintenance' so it should be OK to charge both batteries at once. Just switch the cluster to parallel as you suggest.

Not sure about that. Either the higher voltage from the domestic will fool the charger into thinking it's got a full battery on its hands or the domestic will help charge the starter, to it's own detriment. I'd disconnect the domestic & switch to both to give the starter battery a nice breakfast,

 

[halcyon]

Not sure about that. Either the higher voltage from the domestic will fool the charger into thinking it's got a full battery on its hands or the domestic will help charge the starter, to it's own detriment. I'd disconnect the domestic & switch to both to give the starter battery a nice breakfast,

Should be okay, as the voltage required to put charge into the service bank will be 14 volt plus, the charge voltage to the engine battery will initially be lower, increasing as it's capacity comes up. This means the service will take no charge until the engine battery capacity comes up to near the same as the service battery, but it can be affected if you have large output charger, and small battery.

In theory the VSR should allow the engine to be charged from the service battery charge source, but the BEP one you have may not be bi-directional. check the part number.

 

[pmagowan]

Thanks guys. I had a bit of fun today as the boat was dried alongside to get the bottom scrubbed and repainted. I was just a little concerned as the new battery was reading 12.2 whereas the house battery has been on the charger earlier in the day. Eventually after I got off, which took a bit of chugging and winching as the second high tide was not quite as high as I anticipated, I motored back to Glenarm. I was a little worried about the alternator but the ?BEP battery monitor showed over 13V going in when I was motoring home. When I arrived back both batteries were 12.8-13V after settling. Looks like all is working OK. I will test the next time I plug in to shore power how the charge distributes. I know I had worked all this out a few years ago when I installed all this stuff (with advice from on here) but memory fades!

 

[William_H]

Turn the charger on and check that the domestic battery voltage as tested by a multimeter is over 13v on charge. You8 might want to wait for a while till it comes up. If the VSR is indeed a bidirectional VSR then the engine battery should be paralleled so should read identical to domestic battery. If not then operate the parallel switch on the VSR. Might be described as emergency start. This will put both batteries in parallel. (don't forget to open this switch when engine battery is charged. Yes current will flow form charged battery to discharged battery but not really to the detriment of the charged battery just discharges it a bit. The charger then sho0uld be able to charge both. If you have any doubts about the charge phase then switch off the charger then on again to start charge cycle. good luck olewill

 

[temptress]

I Have a CTEK m200 battery charger plugged into the house 110ah battery. The start battery is connected via a BEP VSR cluster. Do I need to switch the emergency parallel on to charge both? Probably a silly question and I probably knew the answer but just got 2 new batteries and the house is reading 13v whereas the start is reading 12.2v.

YOUR VSR should take care of everyhting for you. So a bit of trouble shooting is needed. Where are you taking the voltage reading and using what?

 

[pmagowan]

Thanks Guys. I am taking the voltage reading from the ?BEP battery monitor which tells you the voltage at each battery plus a percentage charge and amps in/out kinda thing. I only use the voltage part mostly. I presume if the batteries are paralleled prior to switching on the charger it will not mess with it's thinking.

 

[pmyatt]

I Have a CTEK m200 battery charger plugged into the house 110ah battery. The start battery is connected via a BEP VSR cluster. Do I need to switch the emergency parallel on to charge both? Probably a silly question and I probably knew the answer but just got 2 new batteries and the house is reading 13v whereas the start is reading 12.2v.

If you want to use the BEP VSR, then connect battery charger to Start Battery and, when it reaches 13.7 Volts it will automatically close and charge the House Battery.

 

[pmagowan]

If you want to use the BEP VSR, then connect battery charger to Start Battery and, when it reaches 13.7 Volts it will automatically close and charge the House Battery.

Yes, I wondered about that but then I thought it might be confused by the switch and thus a waste of money getting a 'smart' one. I dedcided that it was the house battery that was more likely to be drained and need some TLC since the start battery should only be required for a short time to start the engine and then it should top up quite quickly. I think the problem came when I bought 2 new batteries at Halfords and the charge was significantly different in each one. They say they are full when you buy them but one was and the other was only 12.2 which I would not count as full or close. Now that I have ran the motor they are both fully charged but I will have a look at how thinks work next time I am onboard. It would be nice to see how the battery charger does things. I think it might be smart enough to be good to a battery but not quite smart enough to communicate that to me!

 

[pongoglo]

Yes, I wondered about that but then I thought it might be confused by the switch and thus a waste of money getting a 'smart' one. I dedcided that it was the house battery that was more likely to be drained and need some TLC since the start battery should only be required for a short time to start the engine and then it should top up quite quickly. I think the problem came when I bought 2 new batteries at Halfords and the charge was significantly different in each one. They say they are full when you buy them but one was and the other was only 12.2 which I would not count as full or close.

Interesting. I carry a small Halfords battery as a back up, a 440 CCA. I salvaged it off a car some idiot wrote off in the Asda car-park and it has payed its way. It has convenient handles and is light enough to carry home after a weekend to put on charge. Sadly it doesn't have enough 'Oompf' to jump my starter, I have a BMC 1.5 which seems to need 600 CCA or so min. Had it off charge in the garage for over a week now and its still showing 12.75 which I believe is pretty good. Interestingly I walked around Halford's with my multimetre the other day and tested all the battery's on display - sad I know!. The best showed 12.64 ish and most averaged about 12.56, with the worst 12.43, so I guess my over four year old salvaged jobby is doing pretty well!