Welcome to the UK Window Cleaning Forums

Starting or own a window cleaning business? We're a network of window cleaners sharing advice, tips & experience. Rounds for sale & more. Join us today!

Voltage drop when split relay connected to 13.3 down from.14.4

Messages
140
Location
Northumberland
Hi

I recently put up a post Regarding low flow.

I decided to do some digging around and got hold of an auto electrician who tested most of the connections and what we found was the Live going in in was indeed 14.4 but once the split relay is connected there is a 1 volt voltage drop going in strangely to about 13.3 is that normal?

my low-flow issues happened once I added 2 electric rules to the system and I'm starting to wonder if if this leisure battery has never been charged correctly but I never noticed because I never had the extra equipment drawing more power.

Do you normally lose about 1 volt when a split relay is connected? My next point of call would be to try another relay and see if we still get a 1 volt drop.

Does anyone know @spruce or anyone cheers!

 
Was the leisure battery connected when you measured the 1v drop across the split charge relay? If it was then maybe it was leisure battery trying to charge it's self!

If you are running 2 pumps and 2 reels off a single battery then that is asking quite a lot unless you do lots of miles between jobs. My guess is the leisure battery is on it's last legs and wont hold a charge. 

You might need 2 x 110Ah batteries in parallel and charge on mains each night.

I think you need to investigate a bit more as I wouldn't want you to buy stuff without you testing more and finding the issue as opposed to me guessing.

 
Hi

I recently put up a post Regarding low flow.

I decided to do some digging around and got hold of an auto electrician who tested most of the connections and what we found was the Live going in in was indeed 14.4 but once the split relay is connected there is a 1 volt voltage drop going in strangely to about 13.3 is that normal?

my low-flow issues happened once I added 2 electric rules to the system and I'm starting to wonder if if this leisure battery has never been charged correctly but I never noticed because I never had the extra equipment drawing more power.

Do you normally lose about 1 volt when a split relay is connected? My next point of call would be to try another relay and see if we still get a 1 volt drop.

Does anyone know @spruce or anyone cheers!
13.3 v isn't going to charge much.

If the auto electrician couldn't tell you/identify the problem then you picked the wrong auto electrician. If the voltage is 14.4 volts on one side of the scr and 13.3 volts on the other side there's a fault inside the scr. When the scr activates the battery voltage should be the same both sides.

Unfortunately your alternator will not fully recharge the amount of current you are drawing a day using electric hose reels. With 2 hose reels winding in together you are expecting the leisure battery to work way above its design application. 2 hose reels working at the same time could draw more than 40 amps. I'd be pretty sure your leisure battery is toast.

You are looking for a combo leisure/starter battery, like a Numax or equivalent Lucas (nobody seems to have Numax stock and battery suppliers are sending a poor spec battery as a replacement,) a Battery with a CCA rating is a good start - something in class2 that will drive a motor mover and do wild camping.

Under normal conditions you have to recharge that leisure battery every night you get home, so you need a decent smart battery charger, one that can be left on continuously.

I have a single 105 amp Lucas battery that is a class 2 and the identical specs to a Numax I originally ordered. Comes from the same supplier.

On Saturday we did about 4 hours work on a gutter clear, fascia and gutter clean and window clean. We drew 16 amps from a 105amp battery. On the way home I replaced 6 amps via my B2B charger. I immediately put the charger on the van when I got home and removed it this morning.

As I mentioned previously, I had an old leisure battery that was 7 years old. It was a standard leisure battery. It has been replaced with this Lucas. I see no difference in charging rate when comparing charging rate of both batteries. Just because a combo leisure battery can also deliver enough power to start an engine, it doesn't mean it will accept a faster charge than a standard leisure battery will.

A combo battery isn't as good as a standard leisure battery and neither is it as good as a starter battery. Because of this I don't expect it to last as long as my old battery did.

 
Was the leisure battery connected when you measured the 1v drop across the split charge relay? If it was then maybe it was leisure battery trying to charge it's self!

If you are running 2 pumps and 2 reels off a single battery then that is asking quite a lot unless you do lots of miles between jobs. My guess is the leisure battery is on it's last legs and wont hold a charge. 

You might need 2 x 110Ah batteries in parallel and charge on mains each night.

I think you need to investigate a bit more as I wouldn't want you to buy stuff without you testing more and finding the issue as opposed to me guessing.
I didn't think of this conundrum but basically we are reeling in the two reels alot and using 2 pumps.

I was told reels are low usage.asuming it would be fine seems more trouble now then worth but I thought it was a very good step in the right direction..

If battery need to be bench charged every day that is a step backwards as in a flat.

And previously didnt bench change for a very long time.

 
Last edited by a moderator:
13.3 v isn't going to charge much.

If the auto electrician couldn't tell you/identify the problem then you picked the wrong auto electrician. If the voltage is 14.4 volts on one side of the scr and 13.3 volts on the other side there's a fault inside the scr. When the scr activates the battery voltage should be the same both sides.

Unfortunately your alternator will not fully recharge the amount of current you are drawing a day using electric hose reels. With 2 hose reels winding in together you are expecting the leisure battery to work way above its design application. 2 hose reels working at the same time could draw more than 40 amps. I'd be pretty sure your leisure battery is toast.

You are looking for a combo leisure/starter battery, like a Numax or equivalent Lucas (nobody seems to have Numax stock and battery suppliers are sending a poor spec battery as a replacement,) a Battery with a CCA rating is a good start - something in class2 that will drive a motor mover and do wild camping.

Under normal conditions you have to recharge that leisure battery every night you get home, so you need a decent smart battery charger, one that can be left on continuously.

I have a single 105 amp Lucas battery that is a class 2 and the identical specs to a Numax I originally ordered. Comes from the same supplier.

On Saturday we did about 4 hours work on a gutter clear, fascia and gutter clean and window clean. We drew 16 amps from a 105amp battery. On the way home I replaced 6 amps via my B2B charger. I immediately put the charger on the van when I got home and removed it this morning.

As I mentioned previously, I had an old leisure battery that was 7 years old. It was a standard leisure battery. It has been replaced with this Lucas. I see no difference in charging rate when comparing charging rate of both batteries. Just because a combo leisure battery can also deliver enough power to start an engine, it doesn't mean it will accept a faster charge than a standard leisure battery will.

A combo battery isn't as good as a standard leisure battery and neither is it as good as a starter battery. Because of this I don't expect it to last as long as my old battery did.
My battery is a banner bull 115ah so what would you say how long that should last on average domestic work say reeling in 20x a day x2 and ofcourse 2 pumps going..?

If I remember correctly strangely once the split charge relay is connected the feed-in from the battery that's before it reaches anywhere else

Shows 13.3 when you disconnect the split charge relay then it measures 14.4 so basically from the split charge relay you only getting 13.3 in I think this could be an issue and I'm thinking about out swaping the relay

And going from there . All that said it looks like won't be able to power this just with one battery? 

 
My battery is a banner bull 115ah so what would you say how long that should last on average domestic work say reeling in 20x a day x2 and ofcourse 2 pumps going..?

If I remember correctly strangely once the split charge relay is connected the feed-in from the battery that's before it reaches anywhere else

Shows 13.3 when you disconnect the split charge relay then it measures 14.4 so basically from the split charge relay you only getting 13.3 in I think this could be an issue and I'm thinking about out swaping the relay

And going from there . All that said it looks like won't be able to power this just with one battery? 
1 day and that's it, if you ain't doing much travelling you will need to bench charge your battery every night I am a sole trader with a electric reel and my 105ah battery gets charged every night as it's depleted between by about 50% after a days work and I might only reel in less than 10x a day

 
You need a starter/leisure battery... (a numax 105ah for example) and you need to charge it  every night...the split charge  relay will hardly put any power back in if your doing very little driving with 2 electric reels on the go....

 
Looks like I moved a little bit too soon I totally love the reels they make your life so much easier but I don't think it's suitable unless you have an easy access point to charge every night or 2. Electric reels definitely make life easier for their amazing but I may need to revert to mechanical if I need to be charging batteries every day or two.

There is just one one question left the 13.3 volts when the split relay is connected to the system isnt normal Its meant to be 14.4 all the way until the battery which makes me wonder if there's an issue perhaps I should iron out first and either bypass the split relay to test it or change it?

 
There is just one one question left the 13.3 volts when the split relay is connected to the system isnt normal Its meant to be 14.4 all the way until the battery which makes me wonder if there's an issue perhaps I should iron out first and either bypass the split relay to test it or change it?
Disconnect the leisure battery and isolate the connection at battery end. Then test the voltage either side of the split charge relay with engine running and starter battery fully charged (a good 10 min drive after starting). If there is very little, ideally zero, voltage difference then relay is fine. If it's above a few tenths of a volt then double check the connections to the split charge relay. If they are all clean and tight then does sound like relay has dirty/pitted contacts. If you have skill and if you can get at contacts you might be able to repair the split charge relay.

 
When I had my electric reel fitted. They said when driving the scr will top up the 110 amp battery. But I do very little miles, like has been previously said. So I asked @spruce
it became really clear to me then I needed to manually charge. So I have one pump, one electric reel, so I charge every other day. A while ago I had a small problem. I took it to someone who knew far more than me, he found the earth wire wasn’t quite connected properly so he sorted it out. He said you can easily get three days out of a fully charged battery. But I stuck with my every other day charge. But last week I forgot to charge my battery as normal so on the 3rd day, I found my flow slow. I tried everything air locks etc. Got to lunch time it drove me crackers. Came home put it on charge next day flow back to normal. This is just to put you in the picture with one battery, one pump, one electric reel. So as been said it’s definitely a problem running all your stuff off one battery. 

 
He said you can easily get three days out of a fully charged battery. But I stuck with my every other day charge. But last week I forgot to charge my battery as normal so on the 3rd day, I found my flow slow. I tried everything air locks etc. Got to lunch time it drove me crackers. Came home put it on charge next day flow back to normal. This is just to put you in the picture with one battery, one pump, one electric reel. So as been said it’s definitely a problem running all your stuff off one battery. 
If you didn't know, taking a lead acid below 50% of it's capacity will quickly kill it!!! So much better to charge when required. I would check the rested voltage the morning before work on second day. 50% charged is about 12.2 volts, So if on second morning it's lower than 12.4 v (75% charged) then you might need to charge each night.

 
Last edited by a moderator:
The Spruce Father says charge once every 2 days in summer and each night through the colder months 

*Amendment* 
                      My 105ah battery will deplete down to just under 75% in the warmer months so it gets charged every night 

 
Last edited by a moderator:
If you didn't know, taking a lead acid below 50% of it's capacity will quickly kill it!!! So much better to charge when required. I would check the rested voltage the morning before work on second day. 50% charged is about 12.2 volts, So if on second morning it's lower than 12.4 v (75% charged) then you might need to charge each night.
Thank for that I will check it in the morning. I’ve had this battery 3 1/2 years. Will let you know the answer. Cheers. 

 
If a leisure battery is just running a pump and kept fully charged it will last a long time.

The problem comes when a cleaner starts to demand more and more from his battery. While an electric hose reel wouldn't take much power from the battery's capacity it will require a standard leisure battery to deliver a high current output for the time the reel is working. Leisure batteries aren't designed to do that. 

Even when working on my own with a single Shurflo pump my alternator didn't fully recharge my leisure battery on the way home.

As a leisure battery's charge drops it will accept a higher rate of change, but as the battery becomes more fully charged the charge rate it will accept become less and less. A near fully charged battery may only accept a couple of amps, less than you took out running your Shurflo pump. If you ran your Shurflo pump for 10 minutes from a fully charged battery it would take longer than 10 minutes for your alternator to fully charge that battery up again.

If your leisure battery is very flat it will accept a high charge rate. That charge rate can be well over the recommended charge rate for the capacity of the battery. I've seen my battery taking up to 45 amps when I first start my van's engine after a full days work for a brief few moments before it starts to drop quickly to around 10 amps.

Numax advised me that we should never charge a leisure battery at more than 10% of its capacity for battery longevity. A 110 amp battery shouldn't be charged faster than 11 amps. That's why Numax advised that a 10  charger is suitable for charging leisure batteries up to 165 amps. It's the chargers capacity output the regulates the charge going into the battery.

As Numax says, window cleaners are battery abusers. I'm also a battery abuser by the very nature of our occupation. 

A caravan's motor mover draws a lot a power from the battery, but in most cases the caravan is then connected to 'shore power' and the caravan's in built charger will trickle charge the leisure battery back to fully charged. Our industry doesn't afford our batteries the same luxury. Little wonder the battery manufacturers refuse to action any warranty claims we make.

 
Last edited by a moderator:
Thank for that I will check it in the morning. I’ve had this battery 3 1/2 years. Will let you know the answer. Cheers. 
So my starting point is 2nd day of use with no charge the night before. 12.7 so guys over to you for advice. Should I be charging daily? 

 
So my starting point is 2nd day of use with no charge the night before. 12.7 so guys over to you for advice. Should I be charging daily? 
The battery experts will tell you your battery is within tolerance of being fully charged. 12.7v and above is fully charged. I say tolerance because at 12.7 volts there is still some 'space' for additional charge.

Depending on the length and/or time traveled to your first customer this morning your battery would have had a bit of an additional charge. 

But I would take that 12.7 as ok and bench charge every 2nd night and see how it works out. But monitor it. In winter your battery is less efficient so monitoring it now will be the litmus test provided all things stay equal. If I can use the words of the Numax tech guy I spoke to, "you must be doing something right for your battery to have lasted as long as it has. Keep doing what you are doing. Most window cleaners only get 6 months from their batteries."

 
The battery experts will tell you your battery is within tolerance of being fully charged. 12.7v and above is fully charged. I say tolerance because at 12.7 volts there is still some 'space' for additional charge.

Depending on the length and/or time traveled to your first customer this morning your battery would have had a bit of an additional charge. 

But I would take that 12.7 as ok and bench charge every 2nd night and see how it works out. But monitor it. In winter your battery is less efficient so monitoring it now will be the litmus test provided all things stay equal. If I can use the words of the Numax tech guy I spoke to, "you must be doing something right for your battery to have lasted as long as it has. Keep doing what you are doing. Most window cleaners only get 6 months from their batteries."
Thanks for the advice. 12.7 was before any travelling. It had stood in the garage over night. So I checked it before setting off. But I will bear in mind to check it everyday. I would rather save this battery as long as I can. I charge with a creek 7.0. Put it on charge now, leave it overnight till morning. I’ll see what voltage in the morning and report back. I do keep going to get the numazu charger but not got on with ordering it yet. 

 
Thanks for the advice. 12.7 was before any travelling. It had stood in the garage over night. So I checked it before setting off. But I will bear in mind to check it everyday. I would rather save this battery as long as I can. I charge with a creek 7.0. Put it on charge now, leave it overnight till morning. I’ll see what voltage in the morning and report back. I do keep going to get the numazu charger but not got on with ordering it yet. 
? I looked up a Creek 7.0 charger. If its a CTEK MXS 7.0 then that charger has good recommendations for charging a leisure battery. I would stay with it.

It may have a slightly lower charging rate than my 10 amp Numax but that's no problem.

As I said earlier, your battery won't accept more than a few amps when it comes closer to fully charged so your charger is no worse off than my 10 amp is. If your battery will only accept 5 amps in the recharge cycle then both our chargers will only be able to charge the battery with 5 amps.

 
Last edited by a moderator:
? I looked up a Creek 7.0 charger. If its a CTEK MXS 7.0 then that charger has good recommendations for charging a leisure battery. I would stay with it.

It may have a slightly lower charging rate than my 10 amp Numax but that's no problem.

As I said earlier, your battery won't accept more than a few amps when it comes closer to fully charged so your charger is no worse off than my 10 amp is. If your battery will only accept 5 amps in the recharge cycle then both our chargers will only be able to charge the battery with 5 amps.
Ok thank you. May as well save my money?. Sorry only just noticed it spelt that. Yes it’s a ctek ???. It is a good charger, just thought the numax was supposed to be better. Thanks again 

 
Back
Top