[Jonny D]

Can any one help please I have a 110ah battery running 2 pumps and 2 controllers. Today I went out to work with a fully charged battery and after just 9 small and 1 large house the battery started playing up. It started running slow so I checked my controller it said the battery was at 10.5  but I needed to finish the job I was on so just put up with it but the number just kept getting lower and by the time I managed to finish the house it was at 7 4 and the water was just trickling out the brush. So I had to finish up there and just go home. I was just about to put it on to charge and decided to check the battery again with a volt reader thing my step dad gave me and it now says the battery is sitting at 12.1. I haven't done anything to it since I finished today when it was down at 7.4 and now it's up at 12.1. Does anyone know why it's doing this and what can I do to stop it from happening tomorrow or do I have to just get a new battery?

[Jonny 87]

Check all connections and continuity (if you have a volt metre)

How old is the battery? What make?

[Smudger]

How old is the battery?

They can be effected by the cold weather, personally I'd never rely on just charging it up I much prefer to have it wired into the van and split charge relay.

You do get quite a drop in charge when using 2 pumps at the same time and it's more noticeable on older batteries, the 110 I have that's 18 months old will do about 1.5 hrs before showing signs of needing a recharge my 7 month old batt ( which is also 110 but a good make ) will run over 5 hours before the controller flashes batt

Darran

[Jonny D]

It about 2 year old I think so I can't really complain if I need to get a new one.

[Neil Worsnop]

Voltage will drop when you put a load onto a circuit so that it can appear to 'recover' when you stop working it.

Also some batteries are good at providing a lot of power very quickly whilst others are good at releasing a smaller amount over a long period.  Car batteries for example give lots of power quickly but don't like a gentle trickle for long periods.  Even if two batteries are both rated 110Ah their real world performance can be different.

Insulating a battery and keeping the connections clean and corrosion free will help but ultimately they have a useful life beyond which they need replacing.

As suggested a spit relay will keep it charged and if the situation allows you can always leave the engine running.

[will77]

on some batteries you can unscrew compartments at the top. mine ran low on water a while back and i was just getting 1 day of use. filled it up with pure water. now  get about 3 days from a charge.

[Ian Sheppard]

Very good advice given here. The older the battery the less well it will hold a charge. Most leisure batteries are designed to be deplete to 50% of capacity so with you 110AH battery you can deplete to 55amps.
some batteries can be depleted by 80% occasionally

As the pumps draw amps the voltage will also fall. Now dependent on the battery condition and age how fast the fall off occurs will vary. Also the lower the amps in the battery the more volts falls to compensate in effect the Battery has to work harder to maintain any power output.

The more often the battery is drained below its advised  threshold the less well it will hold a charge.

Certainly check all your cabling replace any worn or damage cable/connectors also keep the cables between the battery - controller and pump as short as possible. Long cable and damage cable increase the effect of volt drop as already mentioned. http://www.thehub360.com/what-is-volt-drop.html

Next your two pumps are drawing around 6 - 8 amps an hour between them, so with good connection cable and a good condition battery 55 divide 8 gives 6.8 hours. However a worn battery or damage cable, Volt drop will reduce this significantly.

If all the cables connectors and fuse are ok, It is likely time for a new battery.

[SherwoodCleaningSe]

2 Pumps really needs a very good battery or 2 batteries.  I was getting through batteries about every 6 months and then invested in an AGM battery, expensive but so far it's lasted 3 years.  Also just because a battery shows 12-13 V it is no real indication of the Amp Hours in the battery.

Simon.

[firefly123]

split charge relays only work if you do lots of miles get your self a ctek battery charger that will charge a110 amp battery they have a desulfation mode this will recover the battery charge up every night mine will run 6 hours with two hose reels they are about 60 quid but well worth it

[SherwoodCleaningSe]

Ditto on the cTek charger.

[Rob Knapman]

If the battery is showing volts as low as that in that short time, its probably ferked

[matthewprice]

Had same problem last week /newish battery  enough charge but when under load controller was flashing bat .cut all connections off , spliced wires together ,all worked great .must have been a bad connection but I could not see it

[colin bird]

I had a 110ah battery do the same thing,when I charged battery,charger light would got out telling me battery charged,went to work,and pump running slow after a couple of jobs.
Had battery checked and it was fully charged.

Tha problem was where the system was connected to lead battery terminals.
The problem was sorted by cleaning terminals and connectors.