Lead Acid battery charger not providing rated current!

Thread Starter

Syed Jahanzeb Ibrar

Joined Oct 7, 2019
5
I have a 24V lead acid battery charger rated at 20A with boost and trickle modes for a standby generator. The charger is connected in parallel with the battery and a load(generators auxiliaries). The auxiliaries consume a load of ~10A when the generator is in service and, 1.5A when it is on standby mode. When the genset is in service the battery charger goes into boost mode and only supplies a max. current of 8-9A causing the batteries to drain. When the battery charger is on trickle mode it only supplies 0.5-1A, again, causing the batteries to drain. What should i do if i want to drive the load and charge the batteries at the same time?
 

crutschow

Joined Mar 14, 2008
23,314
Do you have any info on the charger (brand name, manual, model number, etc.).
It seems strange that it's rated at 20A but only delivers 8-9 amps. :confused:
 

Thread Starter

Syed Jahanzeb Ibrar

Joined Oct 7, 2019
5
Unfortunately no there was no information from the vendor about the manufacturer, manual, etc. they only guaranteed that its rated at 20A. Could it be that the charging algorithm has a current limit?
 

AlbertHall

Joined Jun 4, 2014
8,330
I have a 24V lead acid battery charger rated at 20A with boost and trickle modes for a standby generator. The charger is connected in parallel with the battery and a load(generators auxiliaries). The auxiliaries consume a load of ~10A when the generator is in service and, 1.5A when it is on standby mode. When the genset is in service the battery charger goes into boost mode and only supplies a max. current of 8-9A causing the batteries to drain. When the battery charger is on trickle mode it only supplies 0.5-1A, again, causing the batteries to drain. What should i do if i want to drive the load and charge the batteries at the same time?
What current does it supply if connected to only the battery?
At what battery voltage?
 

Ramussons

Joined May 3, 2013
797
I have a 24V lead acid battery charger rated at 20A with boost and trickle modes for a standby generator. The charger is connected in parallel with the battery and a load(generators auxiliaries). The auxiliaries consume a load of ~10A when the generator is in service and, 1.5A when it is on standby mode. When the genset is in service the battery charger goes into boost mode and only supplies a max. current of 8-9A causing the batteries to drain. When the battery charger is on trickle mode it only supplies 0.5-1A, again, causing the batteries to drain. What should i do if i want to drive the load and charge the batteries at the same time?
How many output terminals does the charger have?
Separate Battery and Load terminals?
If you connect a load in parallel to the battery, a Float-cum-Boost charger will not do its job properly.
 

tautech

Joined Oct 8, 2019
13
Likely the charger is a POS. Adjust its float voltage if you can.
Typically an automotive charger cutoff point is 27.6- 28.4V depending on the battery chemistry. (2* 13.8 - 14.2V)

Are you sure your volt meter is accurate ?
What is the battery type ? FLA, SLA or something else ?
 

Thread Starter

Syed Jahanzeb Ibrar

Joined Oct 7, 2019
5

Thread Starter

Syed Jahanzeb Ibrar

Joined Oct 7, 2019
5

nsaspook

Joined Aug 27, 2009
6,270

RIKRIK

Joined Oct 11, 2019
24
so are the batteries a back up for the generator? or does the generator charge up the batteries? or do you have mains or solar charging them up. Also what sort of batteries, heres a artical on how fast you can charge a battery, "Did you know that a deep cycle battery may actually charge quicker using a slower charge rate? It is true. By slowing the current flow you have removed the 'bottle neck' created by the increased resistance. The resulting heat and friction from trying to charge too fast is gone and the battery can actually absorb the charge faster at the slower speed." https://www.impactbattery.com/blog/2017/05/how-fast-can-i-charge-my-car-battery/

theirs also using less power , the thing isnt a super capacitor ;).
 

Ramussons

Joined May 3, 2013
797
How come? If there is a current limit would we expect the voltage to drop as the load requirement exceeds the current limit?
An Automatic Float cum Boost charger needs to Monitor the Battery Current - particularly the Charging Current for setting its output voltage. In the setup where both the load and Battery are in parallel, there is no way the battery current can be monitored.
If its a charger which is manually set to Float or Charge by reading an Ammeter (which monitors only the Battery current), then its a different matter.
 
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