Hawker Questions

[andyh1956]

Greetings from Mississippi!
I was given two unused Hawker batteries from an estate. But build date is 05/07 & are dead. I remember when I was in Afghanistan being told about the Hawkers & in TM Monthly reading they charge funny & need special equipment to do it, but we never saw any.
Has anybody had any experience trying to bring a Hawker like mine to life?
They would sure look good in my M35A2!
Thanks

 

[droprat]

Super long slow trickle charge! I recouped a couple. Ultimately had to go civilian cause of the set up connections.

 

[andyh1956]

Thanks!
Lowest setting on my shop charger is 2 amps. That too much or should I got find a real trickle?

 

[droprat]

Try 2 amps for several days. Just check it often for heat, leaks etc! See if it comes back to life!

 

[dmetalmiki]

Use the latest version of a pulse (Recovery) inverter charger.
They cost from £12.00 to around £100.00 over here.
We have the cheaper small ones (8 off,(Auto 6volt - 12volt)).. And Two large ones Mid price, (Auto 12volt - 24 volt).
Positively Magic as far as I'm concerned. ('Scuse the pun.)

 

[NDT]

Hawkers are great but 13 years sitting dead will likely have killed one.

 

[FloridaAKM]

My last Deuce from GP came with two hawker 6TL batteries. One will smoke a 100 amp battery tester, the other one, not so much anything. I put that battery on repair mode for several days with a battery charger & it would not come back to life. Wound up replacing both batteries & use the Hawker for various duties.

 

[SCSG-G4]

The thing to remember about AGM batteries is that they cannot stand sustained high voltages! Most chargers allow the voltage to increase as the battery gets close to full charge (think over 15 V). AGM's are very sensitive to that - anything close to steady over 14.5 volts will kill them! Pulse chargers do deliver very high voltages (50 V +) but for very short duration (milliseconds) with long periods of rest (at least in relation to their charge pulse). That is also why they will break up sulfur deposits on cells - high voltage knocks them loose, but the short duration decreases the size of the particles to manageable levels.

 

[glcaines]

AGM batteries are great. You should use a battery charger that is designed to charge AGM batteries. I use a NOCO Genius Model 7200 which will handle various voltages, including 24, and also AGM. The battery charger automatically adjusts to the battery it is connected to regardless of voltage and whether it is AGM or not. I have four of them and have never had a problem. Also, there is a caveat. If the batteries are completely flat, they won't charge just by hooking up the charger. You must have some voltage present and detectible by the charger to charge them. The easiest way is to take battery jumper cables and connect the AGMs by cable to another battery that is already charged. The second battery does not need to be an AGM battery. With them hooked together, hook up the battery charger. The last time I resurrected dead AGM batteries, it took almost 24 hours before one of the batteries started taking a charge and about 5 hours before the second started charging. Once they are even slightly charged, you can remove the jumper cables and continue charging. I was given this information directly from Hawker over the phone. Don't give up. I suspect your Hawker batteries will come back to life.

 

[andyh1956]

OK, I'm sure you mean for me to connect the second charged batt in parallel to the dead Hawker, correct?
I will try this & report back in a few days. One my Hawkers had a LITTLE detectable voltage in it but the other not so much.
Thanks evebody for your help!

 

[SCSG-G4]

OK, I'm sure you mean for me to connect the second charged batt in parallel to the dead Hawker, correct?
I will try this & report back in a few days. One my Hawkers had a LITTLE detectable voltage in it but the other not so much.
Thanks evebody for your help!

Parallel is correct!

 

[andyh1956]

Update!
Happy Holidays from Mississippi everbody!
Hey I went & bought a smaller 10 amp charger from Northern Tool to use around the shop so I wouldn't have to un-hook my big charger from my Hawkers while charging & Behold! They came back to life! Left them babies charging for DAYS on 2 amps & they both hold a load halfway through the green on the tester now!
Now I gotta get my battery box in shape on my M35A2 to hold them.
Thanks for the help!
Andy