intelligent battery charger

I had a smart charger do that Found out the battery was stuffed and got so hot it nearly melted


Was the one in a post above this one about smart chargers

I would take graham advice and have battery checked I run a projecta IC750 in my van charging two deep cycle calcium batteries in parrallel and I leave on all time much better than the converter that was in it at least you get your batteries fully charged. I have another one is the cruiser to maintain the AGM 120 ah battery which gets turned on on weekend to do its thing and the battery does not get hot regards Alan.

Hello John,

here are a couple of checks I recommend to do:

measure the voltage of your battery several hours after it's come off the charger, and record it.
Then connect a load of several amps (like a fridge, or a 12V incandescent light bulb of 21W or similar) to the battery.
And the voltmeter goes across it to let you take readings every 10 minutes over a 2 hour time span.
If the voltage holds up above 12,6V under load at the end of the 2 hour period, there is still hope your battery hasn't suffered too much.

Don't get confused about the anti sulphation voltages/pulses etc, this is marketing gimmick.
Your charger starts off with the bulk charging stage with a voltage of up to 14.4~14.8V.
Ideally, the charger should also check for a shorted out cell, before it applies the full bulk charge voltage.
Some chargers achieve this by sending pulsing current through the battery. This gives the controller enough info about the general state of the battery, and whether or not all cells are intact.
Marketing folks interpret this pulsing as desulphation stage while in reality, this is only a way of testing for the integrity of the battery before subjecting it to the high bulk charging current.

Depending on the state of charge of your battery (say 90% fully charged), this voltage level should be reached within 30 to 60 minutes at the latest.
After another 60 to 120 minutes or so (while the battery absorbs the charge at this voltage level), the charging current should have tapered off sufficiently, causing the charger to drop the voltage back to float level of around 13.6V.

Observe the temperatures carefully because your battery may have dried out to such an extent, that the charging current won't taper off. Thus, the battery gets hotter and hotter while the (dumb, or blindfolded)* charger doesn't notice this and keeps the boost (bulk) voltage up, causing the battery develop even more heat.

If your charger came with a battery temperature sensor, please use it.
Check in the manual, if the charger's got an overriding time limitation on the bulk/absorption stages.

*dumb in this context means, the charger doesn't notice there is anything wrong with the battery.
Blindfolded means, it's got no additional feedback loop via a battery temperature sensor.

Question: did you ever have some loads connected to your battery while it was being charged?

Just let us know and we'll try to pinpoint the problem.

Best regards, Peter

Have you tried to charge the battery with any another battery charger ??

Does the battery still get HOT ??

If so there is a common elemant, the 2 x battery chargers make it Hot, so more than likely it's stuffed

Maîneÿ . . .

Without sounding rude is the charger on the correct setting ( gel, etc) for your type of battery? I have the same charger in my camper and are impressed so far. I'll be watching this thread with interest!

"My plan is to use the onboard battery to power my 12v lights and appliances and to replace the 240v – 12v power converter with the charger so I may use the charger as a power supply."

ANY Smartcharger with 3 or more stages will stay in Absorption Mode (14.4 volts ) FOREVER if you are using it as a Power Supply and the appliances are drawing more than 10 % of the maximum current. i.e. 1.5 amps for a 15 amp charger.

This high voltage apllied for a long time will cook any LeadAcid Battery (Wetcell, GEL, AGM).

If you want to use a Power Supply as a permanent charger it has to put out the FLOAT volatge - 13.6 volts. This will still charge batteries to 100% - it just takes longer.

Solar Regulators have 3 separate connections for Appliance, Battery and Solar Panel to avoid this problem.

Just to follow up, I believe one of you guys were right in that the items using power were causing the charger to remain in charge mode, this was probably the cause of the battery getting hot. Fortunately the battery is still ok. But just an addit the chat=rger itself also had problems and has now been replaced under warranty. Thanks for all of the replies.
John